Cine EI moves the exposure mid point up and down.

Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.

XDCAM-sliding-system-v2 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.

INTRODUCTION:

This guide to Cine-EI is based on my own experience with the Sony PMW-F5 and F55. There are other methods of using LUT’s and CineEI. The method I describe below, to the best of my knowledge, follows standard industry practice for working with a camera that uses EI gain and LUT’s.

If you find the guide useful, please consider buying me a beer or a coffee. It took quite a while to prepare this guide and writing can be thirsty work.


Type



pixel Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.

If you want you can download this guide as a PDF by clicking on this link: Ultimate Guide to CineEI on the PMW. I’d really appreciate a drink if your going to take away the PDF.

In this guide I hope to help you get the very best from the Cine EI mode on Sony’s PMW-F5 and PMW-F55 cameras. The cameras have two very distinct shooting mode, Cine EI and Custom Mode. In custom mode the camera behaves much like any other traditional video camera where what you see in the viewfinder is what’s recorded on the cards. In custom mode you can change many of the cameras settings such as gamma, matrix, sharpness to create the look you are after in-camera. “Baking-in” the look of your image in camera is great for content that will go direct to air or for fast turn around productions. But a baked-in look can be difficult to alter in post production. In addition it is very hard to squeeze every last drop of picture information in to the recordings in this mode.

The other mode, Cine-EI, is primarily designed to allow you to record as much information about the scene as possible. The footage from the camera becoming in effect a “digital negative” that can then be developed in post and the final highly polished look of the film or video created. In addition the Cine-EI mode mimics the way a film camera works giving the cinematographer the ability to rate the camera at different ISO’s to those specified by Sony. This can be used to alter the noise levels in the footage or to help deal with difficult lighting situations.

One further “non-standard” way to use Cine-EI is to use a LUT (Look Up Table) to create an in-camera look that can be baked in to the footage while you shoot. This offers an alternative to custom mode. Some users will find it easier to create a specific look for the camera using a LUT than they would by adjusting camera settings such as gamma and matrix.

MLUT’s, LUT’s and LOOK’s (all types of Look Up Tables) are only available in the Cine-EI mode.

THE SIMPLIFIED VERSION:

Before I go through all the “why’” and “hows” first of all let me just say that actually CineEI is easy. I’ve gone in to a lot of extra detail here so that you can full master the mode and the concepts behind it.

But in it’s simplest form, all you need to do is to turn on the MLUT’s. Choose the MLUT that you like the look of, or is closest to the final look you are after. Expose so that the picture in the viewfinder or on your monitor looks how you want and away you go.

Then in post production bring in your Slog footage. Apply the same LUT as you used when you shot and the footage will look as shot, only as the underlying footage is either raw or Slog you have a huge range of adjustment available to you in post.

THAT’S IT! If you want, it’s that simple.

If you want to get fancy you can create your own LUT and that’s really easy too (see the end of the document). If you want less noise in your pictures use a lower EI. I shoot using 800EI on my F5 and 640EI on the F55 almost all the time.

Got an issue with a very bright scene and strong highlights, shoot with a high EI.

Again, it’s really simple.

But anyway, lets learn all about it and why it works the way it works.

LATITUDE AND SENSITIVITY.

The latitude and sensitivity of the F5/F55, like most cameras is primarily governed by the latitude and sensitivity of the sensor. The latitude of the sensor in these cameras is around 14 stops. Adding different amounts of conventional camera gain or using  different ISO’s does not alter the sensors actual sensitivity to light, only how much the signal from the sensor is amplified. Like turning up or down the volume on a radio, the sound level gets higher or lower, but the strength of the radio signal is just the same. Turn it up loud and not only does the music get louder but also any hiss or noise, the ratio of signal to noise does not change, they BOTH get louder. Turn it up too loud and it will distort. If you don’t turn it up loud enough, you can’t hear it, but the radio signal itself does not change. It’s the same with the cameras sensor. It always has the same sensitivity, but with a conventional camera we can add or take away gain (volume control?) to make the pictures brighter or darker (louder?).

NATIVE ISO:

Sony’s native ISO ratings for the cameras, 1250ISO for the F55 and 2000ISO for the F5 are values chosen by Sony that give a good trade off between sensitivity, noise and over/under exposure latitude. In general these native ISO’s will give excellent results. But there may be situations where you want or need different performance. For example you might prefer to trade off a little bit of over exposure headroom for a better signal to noise ratio, giving a cleaner picture. Or you might need a very large amount of over exposure headroom to deal with a a scene with lots of bright highlights.

The Cine EI mode allows you to change the effective ISO rating of the camera.

With film stocks the manufacturer will determine the sensitivity of the film and give it an Exposure Index which is normally the equivalent of the films measured ASA/ISO.  It is possible for a skilled cinematographer to rate the film stock with a higher or lower ISO than the manufacturers rating to vary the look or compensate for filters and other factors. You then adjust the film developing and processing to give a correctly exposed looking image. This is a common tool used by cinematographers to modify the look of the film, but the film stock itself does not actually change it’s base sensitivity, it’s still the same film stock with the same base ASA/ISO.

Sony’s Cine EI and EI modes on Red and Alexa are very similar. While it has many similarities to adding conventional video camera gain, the outcome and effect can be quite different. If you have not used it before it can be a little confusing, but once you understand the way it works it is very useful and a great way to shoot. Again, remember that the actual sensitivity of the sensor itself never changes.

CONVENTIONAL VIDEO CAMERA GAIN.

Increasing conventional camera gain will reduce the cameras dynamic range as something that is recorded at maximum brightness (109%) at the native ISO would be pushed up above the peak recording level and into clipping if the conventional camera gain was increased because we can’t record a signal larger than 109%. But as the true sensitivity of the sensor does not change, the darkest object the camera can actually detect remains the same. Dark objects may appear a bit brighter, but there is still a finite limit to how dark an object the camera can actually see and this is governed by the sensors noise floor and signal to noise ratio (from the sensors own background noise). Any very dark picture information will be hidden in the sensors noise. Adding gain will bring up both the noise and darkest picture information, so anything hidden in the noise at the native ISO (or 0db) will still be hidden in the noise at a higher gain or ISO as both the noise and small signal are amplified by the same amount.

Using negative conventional gain or going lower than the native ISO may also reduce dynamic range as picture information very close to black may be shifted down below black when you subtract gain or lower the ISO. At the same time there is a limit to how much light the sensor can deal with before the sensor itself overloads. So even though reducing the ISO or gain may make the picture darker, the sensor clipping/overload point remains the same, so there is no change to the upper dynamic range, just a reduction in recording level.

See also this article on gain and dynamic range.

As Sony’s Slog2 and Slog3 are tailored to capture the cameras full 14 stop range this means that when shooting with Slog2 or Slog3 the gamma curve will only work as designed and deliver the maximum dynamic range when the camera is at it’s native ISO. At any other recording ISO or gain level the dynamic range will be reduced. IE: If you were to use SLog2 or SLog3 with the camera in custom mode and not use the native ISO by adding gain or changing the ISO, you will not get the full 14 stop range that the camera is capable of delivering.

EXPOSURE LEVELS FOR DIFFERENT GAMMA CURVES AND CONTRAST RANGES.

It’s important to know (or better still understand) that different gamma curves with different contrast ranges will require different exposure levels. The TV system that we use today is currently based around a standard known as Rec-709. This standard specifies the contrast range that a TV set or monitor can show and which recording levels represent which display brightness levels. Most tradition TV cameras are also based on this standard. Rec-709 does have some serious restrictions, the brightness and contrast range is very limited as these standards are based around TV standards and technologies developed 50 years ago. To get around this issue most TV cameras use methods such as a “knee” to compress together some of the brighter part of the scene into a very small recording range.

Slide2 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
A traditional TV camera with a limited dynamic range compresses only a small highlight range.

 

As you can see in the illustration above only a very small part of the recording “bucket” is used to hold a moderately large compressed highlight range. In addition a typical TV camera can’t capture all of the range in many scenes anyway. The most important parts of the scene from black to white is captured more or less “as is”. This leaves just a tiny bit of space above white to squeeze in a few highly compressed highlights. The signal from the TV camera is then passed directly to the TV and as the shadows, mid range and skin tones etc are all at more or less the same level as captured the bulk of scene looks OK on the TV/Monitor. Highlights may look a little “electronic” due to the very large amount of compression used.

But what happens if we want to record more of the scenes range? As the size of the recording “bucket”, the codec etc, does not change, in order to capture a greater range and fit it in to the same space, we have to re-distribute how we record things.

Slide3 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Recording a greater dynamic range into the same sized bucket.

Above you can see that instead of just compressing a small part of the highlights we are now capturing the full dynamic range of the scene. To do this we have altered the levels that everything is recorded at. Blacks and shadows are a little lower, greys and mids are a fair bit lower and white is a lot lower. By bringing all these levels down we make room for the highlights and the really bright stuff to be recorded without being excessively compressed.

The problem with this though is that when you output the picture to a monitor or TV it looks odd. It will lack contrast as the really bright stuff is displayed at the same brightness as the conventional 709 highlights. White is now only as bright as faces would be with a conventional TV camera and Faces are only a little bit above the middle grey level.

This is how Slog works. By re-distributing the recording levels we can squeeze a much bigger dynamic range into the same size recording bucket. But it won’t look quite right when viewed directly on a standard TV or monitor. It may look dark and certainly a bit washed out.

I hope you can also see from this that whenever the cameras gamma curve does not match that of the TV/Monitor the picture might not look quite right. Even when correctly exposed white may be at different levels, depending on the gamma being used, especially if the gamma curve has a greater range than the normal Rec-709 used in old school TV cameras.

THE CORRECT EXPOSURE LEVELS FOR SLOG-2 and SLOG-3.

Lets look at the correct exposure levels for SLog-2 and SLog-3. As these gamma curves have a very large dynamic range the recording levels that they use are different to the levels used by the normal 709 gamma curve used for conventional TV. As a result when correctly exposed, Slog looks dark and low contrast on a conventional monitor or in the viewfinder. The table below has the correct levels for middle grey and 90% reflectance white for the different types of Slog.

log-exposure-1024x190 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Correct exposure levels for Sony’s Slog.

The white level in particular is a lot lower than we would normally use for TV gamma. This is done to make extra space above white to fit in the extended range that the camera is capable of capturing, all those bright highlights, bright sky and clouds and other things that cameras with a smaller dynamic range struggle to capture.

Let’s now take a look at how to set the correct starting point exposure for SLog-3. You can use a light meter if you wish, but if you do want to use a light meter I would first suggest you check the calibration of the light meter by using the grey card method below and comparing the what the light meter tells you with the results you get with a grey or white card.

The most accurate method is to use a good quality grey card and a waveform display. For the screen shots seen here I used a Lastolite EzyBalance Calibration Card. This is a pop up grey card/white card that fits in a pocket but expands to about 30cm/1ft across giving a decent sized target. It has middle grey on one side and 90% reflectance white on the other. With the MLUT’s off, set the exposure so that the grey card is exposed at the appropriate level (see table above).

Note: To get the waveform to display you must have BOTH the SDI SUB and Viewfinder MLUT’s OFF or BOTH ON. The waveform is turned on and off under the  “VF” – “Display ON/OFF” – “Video Signal Monitor” settings of the main menu. Sadly the cameras built in waveform display is not the best so it may help to use an external monitor with a better waveform display.

LUT-middlegrey41 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Setting the correct exposure for Slog-3 using a grey card. Middle Grey should be 41%

If you don’t have access to a better waveform display you can use a 90% reflectance white card and zebras. By setting up the Zebras with a narrow aperture window of around 3% you can get a very accurate exposure assessment for various shades of white. For SLog-3 set the Zebras to 3% aperture and the level at 61%. Sadly the zebras don’t go below 60%. For Slog-2 using 60% will be accurate enough, a 1% error is not going to do any real harm. You can use exactly the same method for S-Log2 just by using the SLog-2 levels detailed in the chart above.

zebras61 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Setting up the Zebras to measure S-Log3 exposure of white card (90% reflectance white card).
LUT-white61 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Correct exposure for S-Log3 when using a 90% reflectance white target.

The image above shows the use of both the Zebras and Waveform to establish the correct exposure level for S-Log3 when using a 90% reflectance white card or similar target. Please note that very often a piece of white paper or a white car etc will be a little bit brighter than a calibrated 90% white card. If using typical bleached white printer paper I suggest you add around 4% to the white values in the above chart to prevent under exposure.

SO HOW DOES CINE-EI WORK?

cine-ei-menu-small Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Cine EI is selected in the Base Settings page. It works in YPbPr, RGB and Raw main operation modes.

Cine-EI (Exposure Index) works differently to conventional camera gain. It’s operation is similar in other cameras that use Cine-EI or EI gain such as the F5, F55, F3, F65, Red or Alexa. You enable Cine-EI mode in the camera menus Base Settings page. On the F5 and F55 it works in YPbPr, RGB and RAW modes.

IMPORTANT: In the Cine-EI mode the ISO of the recordings remains fixed at the cameras native ISO (unless baking in a LUT,  more on that later). By always recording at the cameras native ISO you will always have 14 stops of dynamic range.

YOU NEED TO USE A LUT:

Important: For Cine-EI mode to work as expected you should monitor your pictures in the viewfinder or via the SDI/HDMI output through one of the cameras built in MLUT’s (Look Up Table), LOOK’s or User3D LUT’s. So make sure you have the MLUT’s turned on. If you don’t have a LUT then it won’t work as expected because the EI gain is applied to the cameras LUT’s.  At this stage just set the MLUT’s to on for the Sub&HDMI output and the Viewfinder out.

Lut-menu-page-on Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
For CineEI to work correctly you MUST turn on the LUT’s for the Viewfinder and/or Sub&HDMI output.
LUT-Camera-Button2 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
You can turn the MLUT’s on and off by pressing the CAMERA button until you see the MLUT controls, then use the hotkeys to turn the MLUT’s on and off.

EXPOSING VIA THE LUT/LOOK.

At the cameras native ISO (2000 on F5, 1250 on F55), when shooting via a LUT you should adjust your exposure so that the picture in the viewfinder looks correctly exposed. If the LUT is correctly exposed then so too will the S-log. As a point of reference, middle grey for Rec-709 and the 709(800) LUT should be at, or close to 42%.

This is really quite simple, generally speaking when using a LUT, if it looks right, it probably is right. However it is worth noting that different LUT’s may have slightly different optimum exposure levels. For example the 709(800) LUT is designed to be a very close match to the 709 gamma curve used in the majority of monitors, so this particular LUT is really simple to use because if the picture looks normal on the monitor then your exposure will also be normal.

LUT-middlegrey42 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Correct exposure of Middle Grey for the 709(800) MLUT. Middle Grey should be 42%. 90% will be 90%.
LUT-white90 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Correct exposure of the 709(800) LUT using a 90% white card, white will be 90%. You can use zebras at 90% to check this level.

The above images show the correct exposure levels for the 709(800) LUT. Middle grey should be 42% and 90% white is… well 90%. Very simple and you can easily use zebras to check the white level by setting them to 90%. As middle grey is where it normally is on a TV or monitor and white is also where you would expect to see it, when using the 709(800) LUT, if the picture looks right in the viewfinder then it generally is right. This means that the 709(800) LUT is particularly well suited to being used to set exposure as a correctly exposed scene will look “normal” on a 709 TV or monitor.

Many of the other LUT’s and Looks however capture a contrast range that far exceeds the Rec-709 standard used in most monitors. So you may need to adjust your exposure levels slightly to allow for this.

The LC709-TypeA Look is very popular as a LUT for the PMW-F5 and F55 as it closely mimics the images you get from an Arri Alexa (“type A” = type Arri).

The “LC” part of the Look’s name means Low Contrast and this also means – big dynamic range. Whenever you take a big dynamic range (lots of shades) and show it on a display with a limited dynamic range (limited shades) all the shades in the image get squeezed together to fit into the monitors limited range and as a result the contrast gets reduced. This also means that middle grey and white are also squeezed closer together. With conventional 709 middle grey would be 42% and white around 80-90%, but with a high dynamic range/low Contrast gamma curve white gets squeezed closer to grey to make room for the extra dynamic range. This means that middle grey will remain close to 42% but white reduces to around 72%. So for the LC709 Looks in the F5/F55 optimum exposure is to have middle grey at 42% and white at 72%. Don’t worry too much if you don’t hit those exact numbers, a little bit either way does little harm.

LUT-white72 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Correct white level for the LC709 LOOK’s. White should be around 72%

 

RECOMMENDED LUT EXPOSURE LEVELS.

Here are some white levels for some of the built in LUT’s. The G40 or G33 part of the HG LUT’s is the recommended value for middle grey. Use these levels for the zebras if you want to check the correct exposure of a 90% reflectance white card. I have also include an approximate zebra value for a piece of typical white printer paper.

709(800) = Middle Grey 42%. 90% Reflectance white 90%, white paper 92%.

HG8009(G40) = Middle Grey 40%. 90% Reflectance white 83%, white paper 86%.

HG8009(G33) = Middle Grey 33%. 90% Reflectance white 75%, white paper 80%.

The “LC709” LOOK’s = Middle Grey 42%. 90% Reflectance white 72%, white paper 77%.

DONT PANIC if you don’t get these precise levels! I’m giving them to you here so you have a good starting point. A little bit either way will not hurt. Again, generally speaking if it looks right in the viewfinder or on your monitor screen, it is probably close enough not to worry about it.

If you ever need to confirm the correct levels for any given LUT or Look it’s really easy. Put the camera in to CineEI.  Turn OFF the MLUT’s (remember you can turn LUT’s on and off from the cameras side information screen by pressing the CAMERA menu button until you see the LUT options at the bottom of the display). With the MLUT’s OFF use a grey card or white card (or maybe your calibrated light meter) to set the exposure for the Slog curve you have chosen.

Once you have established the correct exposure for the SLog, without adjusting anything else, turn on the MLUT’s, ensure the camera is at the native ISO and choose the LUT or LOOK that you want to check.  Now you can measure the grey and white point for the LUT/Look you have chosen and see on the monitor or in the viewfinder what the correct exposure looks like via the LUT. It probably won’t be vastly different from normal 709 in most cases, especially middle grey this tends to stay very close to 42%, but it’s useful to do this check if you are at all unsure.

If  you can, use a LUT, not a LOOK. That’s my recommendation, not a hard and fast rule but if you’re new to CineEI, LUT’s and Looks please read on as to why I say this. Otherwise skip on to Baking-in the LUT/LOOK.

I recommend that for exposure evaluation you should normally try to use one of the cameras built in  MLUT’s not the LOOK’s. Especially if you are new to LUT’s and Looks. This is because the LUT’s behave differently to the Looks when you use a high or low EI.

I found that when you lower the EI gain, below native, the output level of the LOOK lowers, so that depending on the EI, the clipping, peak level and middle grey values are different. For example on my PMW-F5 at 500 EI the LC709TypeA LUT has a peak output (clipping) level of just 90% while at 2000 ISO it’s 98%. This also means that middle grey of the LOOK will shift down slightly as you lower the EI. This means that for consistent exposure at different low EI’s you may need to offset your exposure very slightly (it is only very slight). It also means that at Native EI if the waveform shows peak levels at 90% you are not overexposed or clipped, but at low EI’s 90% will mean clipped Slog, so beware of this peak level offset with the LOOK’s.

When you raise the EI of the LOOKS, the input clipping point of the Look profile changes. For each stop of EI you add the LOOK will clip one stop earlier than the underlying Slog. For example set the LC709TypeA LUT to 8000 ISO (on my PMW-F5)  and the LOOK itself hard clips 2 stops before the actual SLog3 clips. So your LOOK will make it appear that your Slog is clipped up to 2 stops before it actually is and the dynamic range and contrast range of the LOOK varies depending on the EI, so again beware.

So, the Looks may give the impression that the Slog is clipped if you use a high ISO and will give the impression that you are not using your full available range at a low ISO. I suspect this is a limitation of 3D LUT tables which only work over a fixed 0 to1 input and output range.

What about the 1D LUT’s? Well the built in LUT’s don’t cover the full range of the Slog curves so you will never see all of your dynamic range at all at once. However I feel their behaviour at low and high EI’s is a little bit more intuitive than the level shifts and early clipping of the LOOKs.

The 1D LUT’s will always go to 109%. So there are no middle grey shifts for the LUT, no need to compensate at any ISO. In addition if you see any clipping below 109% then it means your SLog is clipping, for example if you set the camera to 500 ISO (on an F5), when you see the 709(800) LUT clipping at 105% it’s because the Slog is also clipping.

At High ISO’s you won’t see the top end of the SLog’s exposure range anyway because the 1D LUT’s range is less than Slog’s range, but the LUT itself does not clip, instead highlights just go up above 109% where you can’t see them and this in my opinion is more intuitive behaviour than the clipped LOOK’s that don’t ever quite reach 100% and clip at lower than 100% even when the Slog itself isn’t clipped.

At the end of the day use the ones that work best for you, just be aware of the limitations of both and that the LUT’s and LOOKs behave very differently. I suggest you test and try both before making any firm decisions, but my recommendation is to use the LUT’s rather than the LOOK’s when judging exposure.

Using the built in MLUT’s?

There are 5 built in MLUT’s: P1 709(800), P2 HG8009G40, P3 HG8009G33, P4 Slog2, P5 Slog3. You can only select the Slog2 LUT when the camera is set to SLog2 in the base settings, the same for the SLog3 LUT. You can also create your own 1D LUT’s in Sony’s Raw Viewer software and user 3D LOOK’s in most grading suites but that’s a whole other subject that I’m not going to cover right here (see this article for user 3D Look creation or go to the additional LUT creation section at the bottom of this document), for now lets just consider the built in LUT’s.

All 3 of the other built in LUTs have an 800% exposure range. The camera itself  has a 1300% exposure range when your shooting in CineEI, Raw,  SLog2 or SLog3 (1300% more than standard gamma). So if you want to see your full exposure range then you should select SLog as your LUT or turn the LUT’s off. However the pictures will be flat looking and lack contrast, which makes accurate focussing harder and you must set your exposure using the SLog levels given above, so in addition Slog 2 will look dark. Note that if you press the “camera” button by the side LCD screen 2 times you can use the hot keys around the LCD to change LUT and turn the LUT’s on and off.

If you use MLUT’s P1, P2 orP3 then the viewfinder pictures will have near “normal” contrast. Your exposure levels will be more normal looking (although P3 should have middle grey at 33% so should look a touch darker than normal) but you won’t be seeing the full recorded range, only 800% out of the possible 1300% is displayed, so some things might look clipped in the viewfinder while the actual recording is not. I suggest switching  the LUT’s off momentarily to check this, or connect a second monitor to the Main SDI to monitor the non LUT output. Do note that if using Slog2/Slog3 as a LUT and at a positive EI ISO you won’t see your full recording range. You will still see up to a stop more than the 800% LUT’s but at high EI’s the Slog2 or Slog3 LUT will clip slightly before the camera recordings. At low EI’s the Slog LUT’s will clip at the same time as the camera, but the level of the clipping point on any waveform display via the LUT output will be lower and this can be a little confusing. Unfortunately if you turn off the LUT’s you can’t get the cameras built in waveform display. This is where an external monitor with waveform becomes very handy to monitor the non LUT native ISO Slog output from the main HDSDI output.

Personally I prefer to use the 709(800) LUT for exposure as the restricted range matches that of most consumer TV’s etc so I feel this gives me a better idea of how the image may end up looking on a consumers TV. The slightly restricted range will help highlight any contrast issue that may cause problems in post. It’s often easier to solve these issues when shooting rather than leaving it to later. Also I find my Slog exposure more accurate as the LUT’s restricted range means you are more likely to expose within finer limits. In addition as noted above I fell the LUT’s behaviour is more predictable and intuitive at high and low EI’s than the LOOK’s.

BAKING IN THE LUT/LOOK.

When shooting using a high or low EI, the EI gain is added or subtracted from the LUT or LOOK, this makes the picture in the viewfinder or monitor fed via the LUT brighter or darker depending on the EI used. In Cine-EI mode you want the camera to always actually record the raw and S-Log2/S-log3 at the cameras native ISO (1250 ISO for F55 or 2000 ISO for F5). So normally you want to leave the LUT’s OFF for the internal recording. Just in case you missed that very important point: normally you want to leave the LUT’s OFF for the internal recording!

Lut-menu-page-sxs-off Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Normally in CineEI you need to ensure that the LUT is OFF for the Main&Internal so that there is no LUT added to the SxS recordings.

Just about the only exceptions to this might be when shooting raw or when you want to deliberately record with the LUT/Look baked in to your SxS recordings. By “baked-in” I mean with the gamma, contrast and color of the LUT/Look permanently recorded as part of the recording. You can’t remove this LUT/look later if it’s “baked-in”.

No matter what the LUT/Look settings, if you’re recording raw on the R5 raw recorder the raw is always recorded at the native ISO.  But the internal SxS recordings are different. It is possible, if you choose, to apply a LUT/LOOK to the SxS recordings by setting the “Main&Internal” MLUT to ON. The gain of the recorded LUT/LOOK will be altered according to the CineEI gain settings. This might be useful to provide an easy to work with proxy file for editing, with the LUT/LOOK baked-in while shooting raw. Or as a way create an in-camera look or style for material that won’t be graded. Using a baked-in LUT/LOOK for a production that won’t be graded or only have minimal grading is an interesting alternative to using Custom Mode that should be considered for fast turn-around productions.

In most cases however you will probably not have a LUT applied to your primary recordings. If shooting in S-Log2 or S-Log3 you must set MLUT – OFF for “Main&Internal” See the image above. With “Main&Internal MLUT OFF” the internal recordings, without LUT, will be SLog2 or Slog3 and at the cameras native ISO.

You can tell what it is that the camera is actually recording by looking in the viewfinder. At the center right side of the display there is an indication of what is being recorded on the cards. Normally for Cine-EI this should say either SLog2 or Slog3. If it indicates something else, then you are baking the LUT in to the internal recordings.

LUT-Slog3-indication Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
The internal recording gamma is shown on the right of the VF. This is recording SLog-3

 

LUT-LUT709-indication Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
The indication here shows that the 709(800) LUT is being baked-in to the internal recordings.

CHANGING THE EI.

Latitude Indication.

At the native ISO you have 6 stops of over exposure latitude. This is how much headroom your shot has. Your over exposure latitude is indicated on the cameras side LCD panel as highlight latitude.

EI-indication Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
High light range indicated in “High Latitude” box as 6E or +6 stops. EI is 2000 (native F5 ISO)

REDUCING THE EI.

So what happens when you halve the EI gain to 1000EI?  1 stop of ISO will subtracted from the LUT. As a result the picture you see via the LUT becomes one stop darker (a good thing to know is that 1 stop of exposure is the same as 6db of gain or a doubling or halving of the ISO). So the picture in the viewfinder gets darker. But also remember that the camera will still be recording at the native ISO (unless baking-in the LUT).

EI-1000iso-indication Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
With the EI reduced to 1000EI from the native 2000EI the High Latitude decreases to 5.0E or +5 stops.

As you can see from the side panel indication, the cameras highlight latitude decreases by 1 stop.

Why does this happen and whats happening to my pictures?

First of all lets take a look at the scene, as seen in the cameras viewfinder when we are at the native EI (This would be 1250 on the F55 and 2000ISO on an F5) and then with the EI changed one stop down so it becomes 500EI on F55 or 1000EI on the F5. The native ISO on the left, the one stop lower EI on the right.

VF-side-by-side Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
2000EI and 1000EI as seen in the viewfinder of an F5 with NO exposure change.

So, in the viewfinder, when we lower our EI by one stop (halving the EI) the picture becomes darker by 1 stop. Note that if you were using the waveform display or histogram the indicated levels would also become lower. The waveform, histogram and zebras all measure the output from the LUT or the image seen in the viewfinder. So as this becomes one stop darker, they would also read 1 stop darker/lower. If using an external monitor with a waveform display connected to the SDI SUB out (SDI’s 3&4) or HDMI and the LUT is enabled for “Sub&HDMI” this too would get darker and the levels decrease by one stop.

What do you do when you have a dark picture? Well most people would normally compensate for a dark looking image by opening the iris to compensate. As we have gone one stop darker with the EI gain, to return the viewfinder image back to the same brightness as it was at the native EI you would open the iris by one stop.

If using a light meter you would start with the meter set at 2000/1250 ISO and set your exposure according to the what the meter tells you. Then you reduce your EI gain on the camera (the viewfinder image gets darker). Now you also change your ISO on the light meter to the new EI ISO. The light meter will then tell you to open the iris by one stop.

So now, after reducing the EI by one stop and then compensating by opening the iris by 1 stop, the viewfinder image is the same brightness as it was when we started.

But what’s happening to my recordings?

Remember the recordings, whether on the SxS card (assuming the Main&Internal LUT is OFF) or RAW always happens at the cameras native ISO (2000 on the F5 and 1250 on the F55), no matter what the EI is set to. As a result, because we opened the iris by 1 stop to compensate for the dark viewfinder or new light meter reading the recording will have become 1 stop brighter. Look at the image below to see what we see in the viewfinder alongside what is actually being recorded. The EI offset exposure as seen in the viewfinder (left hand side) looks normal, while the actual native ISO recording (right hand side) is 1 stop brighter.

VF-and-Internal Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
At 1000EI the Viewfinder image on the left is 1 stop darker than the actual recorded image (on the right) which is recorded at the native 2000 ISO (F5).

How does this help us, what are the benefits?

When I take this brighter recorded image in to post production I will have to bring the levels back down to normal as part of the grading process. As I will be reducing my levels in post production by around 1 stop (6db) any noise in the picture will also be reduced by 6db. The end result is a picture with 6db less noise than if I had shot at the native ISO. Another benefit may be that as the scene was exposed brighter I will be able to see more shadow information.

Is there a down side to using a low EI?

Because the actual recorded exposure is brighter by one stop I have one stop less headroom. However the F5 and F55 have an abundance of headroom so the loss of one stop is often not going to cause a problem. I find that going between 1 and 1.5 EI stops down rarely results in highlight issues. But when shooting very high contrast scenes and using a low EI it is worth toggling the LUT on and off to check for clipping in the SLog image. This can be done from the side panel of the camera by pressing the “Camera” button until you see the MLUT controls on the side display and turning the MLUT on or off.

What is happening to my exposure range?

What you are doing is moving the mid point of your exposure range up in the case of a lower EI. This allows the camera to see deeper into the shadows but reduces the over exposure latitude. The reverse is also possible. If you use a higher EI you shift your mid point down. This gives you more headroom for dealing with very bright highlights, but you won’t see as far into the shadows and the final pictures will be a little noisier as in post production the overall levels will have to be brought up to compensate for the darker overall recordings.

Cine-EI allows us to shift our exposure mid point up and down.  Lowering the EI gain gives you a darker VF image so you tend to overexpose the actual recording which reduces over exposure headroom but increases under exposure range (and improves the signal to noise ratio). Adding EI gain gives a brighter Viewfinder image which makes you underexpose the recordings, which gives you more headroom but with less underexposure range (and a worse signal to noise ratio).

Slide1 Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.
Cine EI moves the exposure mid point up and down.

Post Production.

When shooting raw information about the EI gain is stored in the clips metadata. The idea is that this metadata can be used by the grading or editing software to adjust the clips exposure level in the edit or grading application so that it looks correctly exposed (or at least exposed as you saw it in the viewfinder via the LUT). The metadata information is recorded alongside the XAVC or SSTP footage when shooting SLog2/3. However, currently few edit applications or grading applications use this metadata to offset the exposure, so S-Log2/3 material may look dark/bright when imported into your edit application and you may need to add a correction to return the exposure to a “normal” level. As the footage is log you should use log corrections to get the very best results. As an alternative you can use a correction LUT to move the exposure up and down like the ones for SLog2 available here, created by cameraman and DP Ben Turley. http://www.turley.tv. Sony’s Raw Viewer software does correctly read the Slog2/3 metadata and will automatically add any required offsets. If shooting raw the majority of grading and editing applications will correctly read the metadata in the raw footage and apply the correct exposure offset, so raw normally looks correctly exposed.

See also this article for more information on EI gain and raw on the F5 and F55.

If shooting raw then you may choose to add the S-Log2/3 LUT to your internal SxS recordings. This will then add the EI-gain to the internal SxS recordings, so they will become brighter/darker as if applying actual gain while only the raw recordings remain at the native ISO. This may be useful if you wish to use the SxS recordings as a proxy file for the edit and would like the proxy files to look similar to the way the final footage will look after grading and correction for the EI offset.

WHAT IF YOU ARE SHOOTING USING HFR (High Frame Rate) AND LUT’S CANT BE USED.

In HFR you can either have LUT’s on for everything including internal recording, or all off, not LUT at all. This is not helpful if your primary recordings are internal SLog.

So if you can’t use the LUT’s you can use the VF High Contrast mode. Sadly this is only available in the viewfinder, but I find that it is much more obvious if your exposure is off when you use the VF High Contrast mode.

The VF High Contrast Mode acts as a 709(800) LUT for the viewfinder only. So expose at the native ISO, by eye, using normal 709 type levels and your Slog-3 should be pretty close to perfect.

The camera automatically turns this mode OFF when you power the camera down, so you must re-enable it when you power cycle the camera. This is probably a good thing as it means you shouldn’t accidentally have it turned on.

Sadly zebras etc either measure the LUT output or the Slog, they are NOT effected by the viewfinder HC mode, so in HFR they will be measuring the SLog. Also if the LUT’s are off then you can’t use different EI gains.

CINE-EI SUMMARY:

CineEI allows you to “rate” the camera at different ISO.

You MUST use a LUT for CineEI to work as designed.

A low EI number will result in a brighter exposure which will improve the signal to noise ratio giving a cleaner picture or allow you to see more shadow detail. However you will loose some over exposure headroom.

A high EI number will result in a darker exposure which will improve the over exposure headroom but decrease the under exposure range. The signal to noise ratio is worse so the final picture may end up with more noise.

A 1D LUT will not clip and appear to overexpose as readily as a 3D LOOK when using a low EI, so a 1D LUT may be preferable.

When viewing via a 709 LUT you expose using normal 709 exposure levels. Basically if it looks right in the viewfinder or on the monitor (via the 709 LUT) it almost certainly is right.

When I shoot with my F5 I normally rate the camera as 800EI. I find that 5 stops of over exposure range is plenty for most situations and I prefer the decrease in noise in the final pictures. I rate the F55 similarly at 640EI. But please, test and experiment for yourself.

QUICK GUIDE TO CREATING YOUR OWN LOOK’s (Using DaVinci Resolve).

It’s very easy to create your own 3D LUT for the Sony PMW-F5 or PMW-F55 using DaVinci Resolve or just about any grading software with LUT export capability. The LUT should be a 17x17x17 or 33x33x33 .cube LUT. This is what Resolve creates by default and .cube LUT’s are the most common types of LUT in use today.

First simply shoot some test Slog3 clips at the cameras native ISO. You must use Slog3 if you want to use User 3D LOOK’s in the camera. In addition you should also use the same color space for the test shot as you will when you want to use the LUT. I recommend shooting a variety of clips so that you can asses how the LUT will work in different lighting situations.

Import and grade the clips from the test shoot in Resolve creating the look that you are after for your production or as you wish your footage to appear in the viewfinder of the camera. Then once your happy with the look of the graded clip, right click on the clip in the timeline and “Export LUT”. Resolve will then create and save a .cube LUT.

Then place the .cube LUT file created by the grading software on an SD card in the PMWF55_F5 folder. You may need to create the following folder structure on the SD card. So first you have a PRIVATE folder, in that there is a SONY folder and so on.

PRIVATE   :   SONY   :    PRO   :   CAMERA   :    PMWF55_F5

Put the SD card in the camera, then go to the “File” menu and go to “Monitor 3D LUT” and select “Load SD Card”. The camera will offer you a 1 to 4 destination memory selection, choose 1,2,3 or 4, this is the location where the LUT will be saved. You should then be presented with a list of all the LUT’s on the SD card. Select your chosen LUT to save it from the SD card to the camera.

Once loaded in to the camera when you choose 3D User LUT’s you can select between user LUT memory 1,2,3 or 4. Your LUT will be in the memory you selected when you copied the LUT from the SD card to the camera.

52 thoughts on “Cine-EI Mode when recording S-Log2/3 and raw on the F5 and F55.”

  1. “In most cases however you will probably not have a LUT applied to your primary recordings.”

    Aside from when you are shooting RAW, which other case would be an exception to having a LUT internally recorded to the SXS cards? Say for an example you have a limited time to grade the footage, would having a LUT applied internally help you or hinder you in that process? Or would you be shooting yourself in the foot by altering the cameras native ISO? I’ve been experimenting with Abel Cines’ scene profiles but I haven’t been too particularly pleased with any of them with an exception to the JR45Cine file. I know how important it is to properly grade the footage, it’s just the place where I am employed has strict deadlines and they would like as minimal color correction as possible -_-

    Anyways big fan of your blogs! thanks for all of your help and knowledge!

    -Freddy

    1. You could add a LUT and then add that to the internal recordings if you wanted. There are a few concerns with that at the moment. One is that you will be limited to a 1D LUT so no saturation adjustment is possible. The other is that as you are now changing the gain of the recordings when you change the EI you will restrict your dynamic range. I’m not saying don’t do it, as always with these things do what works for you, just understand the limitations.

  2. Thanks for the advice. I’ll continue to do some tests. I also noticed that if you Do Not have the “Main&Internal Recording” turned On and you Select S&Q recording, it turns off the Viewfinder Luts as well as the Sub automatically. Just something I’ve noticed. Not sure if that’s normal or not. Thanks again. Very much appreciated as always Mr. Chapman.

    -Freddy

  3. “The only exception to this would be when shooting raw. The raw will always be recorded at the native ISO, but it is possible to apply a LUT to the SxS recordings, the gain of this LUT will then be altered according to the CineEI gain settings”

    I’m a bit confused about what constitutes an SxS recording. If I’m recording both 4k Raw to the R5 and xavc to the SxS simultaneously, do I want Main/Internal MLUT on or off? Or does it make no difference?

    Thanks

    1. Depends on whether you want Log recordings on the SxS cards or recordings with a baked in look. Internal MLUT ON will bake in the LUT to the SxS recordings.

  4. I have noticed that shooting in Slog2 and set the shooting mode in custom and the colorspace in normal, the picture on the monitor and the viewfinder will look normal as in Rec 709. I haven’t find a method to view the typical Slog2 picture on the monitor as well in the viewfinder. Do you recognize this?

    Thanks for sharing your experience!
    Rick

  5. When recording RAW on the R5 and Slog2 internally on the F5 (at 2000EI), using the P4 Slog2 LUT and false color to expose 18% gray at 32 in the viewfinder, will 18% gray actually be at some equivalent of 50 IRE in the RAW recording? Similar to exposing “at stop” with my light meter. Or am I just over-thinking this? I have an upcoming shoot and don’t have access to an F5 to test this myself.

    Turning on the P4 Slog2 LUT has no effect in the viewfinder and I expected to see some difference as with the other in-camera LUTs. So are you actually applying a LUT in the P4 setting or simply viewing the Slog2 image?

    1. The raw recordings are linear so middle grey will actually be 18% in the recording itself, but you don’t normally view the raw files in linear, normally you will be viewing the raw via a LUT converting it to 709, log or whatever and once converted middle grey will then be at the appropriate level for the viewing LUT.

      The S-Log2 LUT allows you to view the S-Log as shot but with the addition of any EI gain.

  6. Why is it that, when I am in S-Log3 and and I have the SDI (Sub) & HDMI MLUT On and the Viewfinder MLUT Off, the waveform disappears from the viewfinder? I would like to be able to send an LUT graded to my client and be able to shoot with the ungraded SLog3 picture in my viewfinder (along with a waveform image to tell me where everything is). Is this a bug in my F5 or is this the camera’s design?

    1. It is strange, but normal behaviour. The Waveform monitor was a feature added after a lot of user requests, perhaps these odd combinations of LUTs and outputs are the only way they can make this bonus feature possible.

  7. Alister,

    Thank you SO much for your helpful blog posts. I cant express enough how grateful I am that you take time to post these things.

    I have a few questions…

    I want to preface them with my understanding of the whole EI mode, to make sure I’m correct.

    My understanding: In EI mode the native ISO (2000) is always what is being recorded. You should always record at 2000 ISO, even when not in EI mode, otherwise you are decreasing your dynamic range. The EI shifts you make are not actually having any tangible effect to the recording. It is simply a tool to affect the image you see on your monitor, essentially a LUT just for exposure alterations.

    My main question: 18% grey is meant to be recorded at 32% IRE for SLOG2.. by decreasing your EI by 1000 and opening your aperture 1 stop, your actual recording would then place 18% grey higher than 32% IRE. When you bring the clip back down 1 stop in post you return 18% grey to 32% IRE… HOWEVER, because your original recording placed 18% grey higher than it should be… wouldn’t that mean we have lost valuable skin tone detail and shades??? Thus, we have to make a trade off between noise and skin tone data?

    Additionally, I have an F5 too. You say you rate yours at 800EI… I want to clarify something.. Do you always shoot at 800EI? Therefore, you essentially overexpose all of your images by a little over a stop (1.3 to be precise) and are always required to reduce the exposure in post for every shot???

    Also, by your philosophy, does that mean that for MOST shots you should rate your EI lower than 2000? (I figure, certainly for any lowlight scenarios)
    If so, in what scenarios should you increase your EI? (Being that there is already so much headroom) Or in what scenario might you just want to leave it at 2000?

    Thank you!! 🙂

    1. Everything you have said is correct. Note that I am primarily shooting raw, so there is no gamma or log compression of highlights, so having a brighter image is good (provided it’s not clipped) and when you bring the raw into post the software automatically adds compensation for the EI gain, so the exposure is corrected automatically. With Log shooting 1 stop brighter is OK (so EI 1000) but you must use proper log corrections or you will loose contrast. 2 stops brighter is really pushing things with Log. You can do it, but it wouldn’t be my recommendation.

  8. Hi Alistair,

    Thanks for your article, very informative reading.
    Could you explain further why you don’t recommend using the built in Sony LOOKS (3D Luts) when shooting Slog2/3. Why does it make exposure trickier?

    Thanks in advance.

  9. So in in a “normal” shooting situation.. maybe an interview where of course skin tone is most important.. with SXS log recording would you advise to keep the EI at 2000..?

    Thanks

  10. Alister,
    If the waveform monitor displays with the LUT applied, how can one be certain that the highlights are within range?
    Thank you,
    JD

  11. Alister,

    Sorry, I meant that since the waveform does NOT display when the Monitor LUT is applies, how can one know for sure that the highlights are not blown out?

    Also, what is the technical difference between S-Log S-Gamut color space and Matrix?

    Thank you!
    JD

    1. The wave form will display when the monitor LUT is applied provided you have SDI Sub ON and MLUT’s on for both VF and SDI sub.

  12. You mention in the summary that you prefer to rate your F5 at 800EI. Why 1 1/3 stop as opposed to just 1 stop at 1000EI? Is it purely an aesthetic choice (noise to signal vs needed headroom) or is there a technical reason?

    Cheers,
    Nick

    1. Simply because 800 ISO is a standard camera ISO, 1000 ISO is a slightly odd ISO. Most cameras and light meters run 200 – 400 – 800 – 1600 – 3200 ISO etc.

  13. Alister,

    Thanks for the advice; this is very useful. Do you have zebra 2 at 100% and you’re just showing that zebra? Or do you also display zebra 1?

    Thanks,
    Fergus

  14. Hi Alister,

    I have been a successful documentary cameraman for twenty years. Got more jobs then I could handle.
    Now I have been ill for four years, and being better, notice that EVERYTHING what was ever a certainty technically has been changed.

    Doing my first steps back on the professional (and sales) ladder is exciting. But help in this new world is welcome.

    Three major things are helpful:
    – practice
    – a lot of self-criticism
    – your blog

    I remark that other blogs and sites from professional cameramen lately change into salestalk for courses or appearances, or are not updated anymore or enough.

    Free information like you give is very valuable.

    So thanks very much and a cup of coffee is on the way.

    David

    ps twenty years ago, as a youngster wanting to try to get into the business of television, I once called Sony to receive a manual from a sony dxc-m3.
    For receiving this knowledge I payed 500 €…

  15. All very appreciated and interesting. Trust you enjoy the cold one.
    For sake of debate, opinion, open forum etc, if I can add my two pennies worth. In fact not mine, but rather Sony Pinewoods current thinking, of which I’ve been finding, in the right situation, rather useful:
    (as none of us is saying there is only one way to best use the F55, do humor me)
    I’m a lighting cameraman, who doesn’t edit. I hand my rushes over to an editor I often will have little communication with (annoying, but not my call). As an F55 owner, I get frustrated with post still moaning about XAVC, transcoding etc. A lot of the more ‘jobbing’ work I do, the budget limitations, turn around etc means that rushes that need a lot of grading are often unpopular. Hence the use of this ‘middle way’.
    I think we all kind of agree that to use this camera in ‘Custom’ mode is a shame. I started in film and am excited to return to this world over previous video. Lots of things very right about ‘Cine EI’.
    So, when appropriate, I do burn in the look (internal & main on). I use ‘look’ over ‘lut’ and use profile 3, Slog2-709. I also drop the ISO to about 1000 to encourage a little over exposure (something we all still struggle to do naturally post video). Importantly, I set the very useful ‘high & low key’ in assignable 3, which I use to check whats being recorded above and below. I don’t use zebras or waveform, but rather viewfinder/monitor (light meter if appropriate) and high & low.
    The rushes could be ready to broadcast, if a little desaturated. But importantly, are nicely ready for a tiny or larger grade, has the cameras 14 stops in there and a quick fire way to get far more out of the camera than ‘custom’ can offer with post light rushes.

    What do we think? (be nice). It seems a good middle way at the moment for me. Like I say, not always. The thing is, without direct dialogue with post, there can be so much misunderstandings about what S-log the material was shot at etc. A recent 4k job, the editor rang in a right state saying the footage was soft and over exposed. Neither true and all resolved (Premier adding a 709 LUT??). Just an unnecessary stress being newly responsible for rushes well into the edit. Well, I’m always responsible for the rushes, but hopefully you know what I mean.

    1. If you’re baking in the LUT, then dropping the ISO won’t result in an over exposed image in the same way as using EI does. When you bake the LUT in, what you see is what you get. Baking in is a perfectly valid workflow and very useful. But once baked in there is no longer any “log” aspect to your footage, it’s just conventional footage.

      As you cannot view raw footage directly Adobe has to apply a LUT to make it viewable. It apply’s 709(800) by default, but it can also use SLog2 as the LUT.

      Thanks for the drink!

  16. Alister, thank you very much for your time and dedication to educating us all!

    Question: I have created a 1D LUT in Sony’s Raw Viewer and use it in camera.
    Our editor says he cannot import this LUT into Davinci Resolve 10 … it’s not recognized. Does the LUT need to be exported in a different format than Sony’s .LTD file type?

  17. Allister all your information and guidance is an invaluable source of learning, thank you! Could you explain why my f55 is locking me out of selecting 4k in base settings when shooting RAW?

    Also Is there anyway to shoot Proxies in HD or 2k?

    1. You cna’t shoot 4K raw plus 4K compressed at the same time. Only 4K raw plus 2K or HD compressed. You can shoot HD XDCAM as a proxy alongside XAVC on the same card on the F55., but nothing smaller than 50mbps.

  18. Thanks for the great guides, documents and info Alister. Enjoy a Singapore Beer on me. By the way if you get a mo. I would be interested in your opinion. Before I manage to get around to hiring some kit and giving it a go, I am wondering on the suitability of ProRes HQ vs XAVC on the new FS7 (or FS700+O7Q) for green screen work. In the particular project I have in mind there will be lots of movement and tracking of comp’ed in elements the actor will be crossing. I have read a bit about XAVC not being ideal for this. We currently use ProRes in post and find it very durable.
    Any insight would be appreciated.
    Regards Phil

    1. XAVC-I is very good and can be used for green screen, but ProRes does have a slight edge for green screen. One thing to consider: ProRes at 4K is 880Mbps, huge files, a 64GB card would only hold 9 mins of footage. XAVC is only 240Mbps, so you get 30mins on a card.

      If your production is HD, consider shooting 4K XAVC and keying at 4K, this will give a final HD result as good as, if not better than keying HD ProRes. XAVC is designed as an aquisition codec, once in your edit domain you would continue to render in to ProRes.

  19. Hi Alister – made a donation for such informative page !! Thanks

    I’ve gone from a EX1 with a Letus adapter to a Nikon F800 to brand new FS7 :o)
    S LOG is NEW TO ME and your page has given me a great starter. I enjoy grading so looking forward to using the S log 3 – hopefully getting the best out FS7

    I’m stuck a stupid problem – please forget my lack of camera basics – I’m far better at the creatives than technical sometimes.
    I got the camera pretty set up in S log 3 including understanding exposure.
    I can’t seem to take a colour balance in S log3 …… have the camera white balance presets that I SEE MAKE a difference to the colour cast in my view finder when I flip through them (viewfinder LUT 709 applied) … but I can’t use a the WB set button to do white colour balance anymore – the function does not work. Does this mean I don’t need to do a white balance anymore and just a just it i the grade ? Sorry – am I totally missing something here. Thanks in advance

    1. It is normal to do you final color tweaks in post, so you use the preset to get the approximate WB in camera and then tweak in post.

  20. Alister,

    What would be the main reason behind NOT using a 709 LUT shooting RAW? You could use an SLog LUT but then you would just have to base your settings on the SLog exposure tables? I just want to make sure I have this right. The SLog LUT is mainly for people who like to expose with that look? In RAW it seems like the only way to visibly see the EI changes you make is by using a LUT of some sort but why might someone choose not to?

    On the flip side. When shooting XAVC and recording SLog it seems like it is more beneficial to not use a LUT correct?

    Can you also send me prices on training sessions?

    Thanks!

    1. Yes you can use S-log as a LUT for raw and yes you would then base your exposure on the appropriate S-Log levels. The reason for using the S-log LUT is to allow you to see the full range the camera can capture, 709 can’t show you the full range. To sensibly view linear raw you must convert it from raw to some form of conventional video.

      When shooting XAVC using a LUT on the VF or monitor output will help you asses exposure much more easily than trying to use grey cards or some other technique to get the correct S-log grey and white levels. An exposure shift of just 7% is the equivalent to a one stop shift when viewing S-log3 and this can make accurate exposure tricky. Use the 709(800) LUT for your monitoring and you can expose using conventional TV levels and a 11% shift is one stop. In addition the increased contrast makes focussing easier.

  21. Hi Alister,

    Thank you for sharing your knowledge.

    Question: What are the advantages of using Cine-EI over Custom? I am curious, because I love the idea of getting back to the “film-way” (Cine-EI) of working but I like the fact that you can do a white balance in “custom”. What am I missing?
    Thank you!

    1. Well with film stocks you only have a choice of tungsten or daylight and any color correction is done either with filters or in post production and Cine-EI is the same, you fine tune the color in post.

      As the camera is attempting to capture the sensors full dynamic range the gain of the R, G and B channels must be very carefully matched. A variable white balance could lead to gain miss matches that may result in clipping in one channel but not the others giving some very nasty images.

  22. Hi Alister,

    Thought you might need a cocktail.. you’re advice, experience and time taken to write this information is so appreciated.
    I’ve spent the last few weeks doing a lot of reading and testing with the F55- it is a tricky little beast in lots of ways. (You cant do this if you have this on etc..)

    I shoot a lot of docs. A lot of the time, it’ll be having a proper grade, so i definitely want to get the best material possible with maximum latitude and workability in the grade. I’ve re read this article now a few times. It’s magic the extra range in the highlights you get from upping the EI, and being able to produce cleaner images by lowering it is obviously great too.

    A quick test shooting across a room with a window in shot showed the extreme difference in the extra range you get using SLOG3 compared to HG4. Made me think I never want to use the hypergammas!

    Is there any reason I cannot shoot run and gun, in Cine EI mode- still raising and lowering the EI like I do with ISO, (So i can effectively see what they’ll be able to achieve in the grade, but knowing it isn’t being baked in) ? As you cannot use MLUTs in custom mode- if I want to shoot Docs in SLOG3 this seems to me the only way to go about this? Would you agree?

    If I know there wont be time for a grade (very rare for my work) I can bake in the LUT- which am I right in thinking means the EI effectively becomes the same as if I was raising or lowering the ISO if the camera was in custom mode..?

    It would be BRILLIANT to hear your thoughts,
    Thank you
    Woody

    1. Of course you can use CineEI for run and gun. I would not bake the LUT in in camera. It only takes a few mouse clicks to add the LUT in post.

  23. Hi Alister,

    Please forget my previous question (It was at the end of a 18hour day and I didn’t make much sense.)

    Thanks again for all the useful info.

    Anyway, I have a very simple question:

    I shoot a lot of verité doc series and when I am in a “dark” environment (like a bar at night for example) with no time to add lighting, I usually switched from Cine EI to Custom to be able to push the gain, but after reading your article it seems that if I leave it in Cine EI and let the scene be underexposed, I could have bumped the gain up in post with the same results. Is that true?
    To be clear: is bumping the gain up in camera the same as bumping the game in post?
    Thank you so very much!
    Frederic

    1. Adding gain in camera or in post is very similar. However gain added in camera is prior to compression and this can mean a slightly cleaner end result. The beauty of adding gain in post is that you can selectively add gain to different parts of the image only adding gain where it’s needed.

  24. Just want to say thanks for your publishing and also for your involvement in blogs!
    I´m wondering what is so special about Singapore beer, but Cheers! 😉
    Greetings from Vienna

  25. Hi Alister,
    Great arcticle!One Question re zebra levels in S-LOG-2 GAMUT mode,In custom mode I always have the Zebra levels at 75% for reference.Is it possible to leave it at this level
    in S-LOG-2 GAMUT mode instead of 61% as stated since my eye is accustomed to exposing at 75%?

    R.

    1. Not unless you want to be 2.5 stops over exposed. The 61% id for WHITE not for skin tones. You must understand that brightness levels for log are totally different to standard gammas.

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