Category Archives: cameras

Will a bigger recording Gamut give me more picture information?

The short answer is it all depends on the camera you are using. With the F55 or F65 then S-Log2/S-Gamut and S-Log3/S-Gamut3 will give you a larger range of colours in your final image than S-Log3/S-Gamut3.cine. But if you have a PMW-F5, PXW-FS7 or PXW-FS5 this is not going to be the case.

What is Gamut?

The word Gamut means the complete range or scale of something. So when we talk about Gamut in a video camera we are talking about dynamic range and color range (colorspace) taken together. Then within the Gamut we can break that down into the dynamic range or brightness range which is determined by the gamma curve and the color range which is determined by the colorspace.

Looking at the current Sony digital cinema cameras you have a choice of 3 different gamuts when the camera is in log mode plus a number of conventional gamuts you get when shooting rec-709, rec-2020 or any other combination of rec-709 color with cinegammas or hypergammas.

Log gamma and gamuts.

But it’s in the log mode where there is much confusion. When shooting with log with the current cameras you have 3 recommended combinations.

S-Gamut (S-Gamut colorspace + S-log2 gamma).

S-Gamut3 (S-Gamut3 colorspace + S-Log3 gamma).

S-Gamut3.cine (S-Gamut3.cine colorpace + S-Log3 gamma).

The S-log2 and S-log3 gamma curves both capture the same dynamic range – 14 stops, there is no difference in the dynamic range captured.

In terms of the range of colors that can be recorded S-Gamut and S-Gamut3 are the same size and the largest recording colorspaces the cameras have. S-Gamut3.cine is a smaller colourspace but still larger than P3 (digital cinema projection) or rec-709.

Gamuts-only Will a bigger recording Gamut give me more picture information?

But those were all designed for the F55 and F65 cameras that have extremely high quality (expensive) colour filters on their sensors. The reality is that the F5/FS7/FS5 sensor cannot see the full range of any of the S-Gamut colorspaces so in reality you gain very little by using the larger versions. Don’t expect to see a noticeably greater range of colours than any of the other colour modes if you have the F5/FS7/FS5. But all the LUT’s designed for these cameras are based on the S-Gamuts and if you want to mix an FS5 with an F55 in one production it helps to use the same settings so that grading will be easier. It is worth noting at this point that most natural colors do fall within Rec-709, so while it is always nicer to have a bigger color range it isn’t the end of the world for most of what we shoot.

S-Log3 is a great example of what it means to have a bigger recording range than the camera can “see”. S-log3 is based on the Cineon film transfer log gamma curve developed back in the late 1980’s. Cineon was carefully tailored to match film response and designed around 10 bit data (as that was state of the art back then). It allows for around 16 stops of dynamic range. Much later, Arri and many others then adapted Cineon for use in video cameras – The “C” in Arri’s LogC stands for Cineon.

When Sony started doing wide dynamic range cameras they developed their own log gammas starting with S-Log, then S-Log2. These curves are matched very precisely to the way a video sensor captures a scene rather than film. In addition they are matched to the sensors actual capture range, S-Log can record 13 stops as that’s what the sensors in the cameras with S-Log can see. Then S-Log2 is 14 stops as the second generation cameras can all see 14 stops. As a result of being purpose designed for a video sensor, when using S-Log2 you maximise the entire recording range because the sensor is matched to the log which is matched to the record range.

But, these curves drew much criticism from early adopters and colorists because they were very different from the Cineon curve and all the other log curves based on this old school film curve. Colorists didn’t like it because none of their old Cineon LUT’s would not work as expected and it was “different”.

In response to this Sony then developed S-Log3 and surprise, surprise – S-log3 is based on Cineon. So S-log3 is based on a 16 stop film transfer curve, but the current cameras can only see 14 stops. What this means is that the top 14% of the gamma curve is never used (that’s where stops 15 and 16 would reside) and as a result s-Log3 tops out at 92% and never gets to the 107% that S-Log2 can reach. If Sony were to release a 16 stop camera then S-Log3 could still be used and then it would reach 107%.

Coming back to colorspace. If you understand that the sensor in the F5/FS7/FS5 cannot see the full colour range that S-Gamut or S-Gamut3 are capable of recording then you will appreciate that like S-log3 (that is larger than the camera can see and therefore part empty) many of the possible code values available in S-Gamut are left empty. This is a waste of data. So from a colourspace point of view the best match when shooting log for these cameras is the slightly smaller colorspace S-Gamut3.cine. But S-Gamut3.cine is meant to be matched with S-Log3 which as we have seen wastes data anyway. If the camera is shooting using a 10 bit codec such as XAVC-I or XAVC-L in HD there are plenty of code values to play with, so a small loss of data has little impact on the final image. But if you are recording with only 8 bit data, for example XAVC-L in UHD then this does become much more of a problem and this is when you will find that S-Gamut with S-Log2 is going to give a better result as S-Log2 was designed for use with a video sensor from day 1 and it maximises the use of what little data you have.

Anatomy of a shot. Night Scene in Arctic Norway – Fujinon lenses, Stella Lights.

I have just return from one of the most challenging shoots I have been involved in. The shoot took place over 5 days in and around Tromso in Norway. The aim was to gather footage to show off the capabilities of a new type of 4K TV from Phillips.

We shot the Northern Lights, we shot dog sledding , snow mobiles, shots of the city and sailing on the fjords. Each part of the shoot had many challenges and a lot of the shoot took place at night and at night the crew slept in cabins, tents and on the yachts. Shooting from the ice and snow covered deck of a yacht in temperatures well below zero is not something I enjoyed. And to top it all off the weather was pretty grim fro most of the shoot. Heavy snow showers, freezing temperatures and towards the end strong winds.

Because image quality is paramount for this project I choses to use the best lenses I could, but at the same time space and time constraints dictated that zoom lenses would be desirable. We were shooting 16 bit raw as well as XAVC class 480 on my PMW-F5 and some pick-up shots in UHD XAVC-L on a PXW-FS5. For the PMW-F5 the primary lens was the Fujinon Cabrio XK6x20, 20-120mm PL zoom and to ensure we had similar looking images from the FS5 I used the new Fujinon XF 18-55mm. I have to say that I’m quite in love with both of these lenses.

fujinon-xk6x20-20-120mm-t3-5-pl-mount-lens-cc1-e1490981959479 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
Fujinon Cabrio XK6x20 PL mount cinema zoom. A beautiful lens!

The Cabrio 20-120 is a beautiful lens and it’s really nice to have a servo zoom that is truly parfocal. The 20-120 produces really nice images even in the most challenging of conditions and at T3.5 it’s reasonably fast throughout the entire zoom range. This was the lens that I used for the majority of the shoot, in particular for the many night scenes we shot. The E-Mount 18-55 on the FS5 produces images that matched really well with the bigger lens and camera. This is a combination I would love to use on more shoots where the budget will allow.

One particular scene that we had to shoot was particularly challenging. It was a set up shot of a night time arrival of a couple of snowmobiles at a Sami camp site. The Sami people are the indigenous people of Northern Norway and they have a particular style of tent know as a Laavu which is similar to a teepee or wigwam. The idea behind the shot was to have the snow scooters arriving with headlights blazing and for the drivers to then enter the tent lit only by the light of a campfire inside the tent. At the time of the shoot it was snowing heavily and was totally dark. Turn off the lights of the snowmobiles and you could not see a thing.

A007C001_170317I9snwscter-wide-1.-e1490980652498 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
Wide shot of the snowmobiles arriving at the camp in the dark.

While modern cameras like the F5 are very sensitive, the light of a campfire inside a tent will not adequately light a scene like this on it’s own. I didn’t want a totally dark background, so I decided that I would subtly light the trees of the forest that we were in to add some drama and give some depth to the background and a sense of being in a forest.

In-tent-wide-e1490980747645 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A slightly closer shot of the tent with backlit trees behind it.

As we were travelling continuously on this shoot there was no space for a large or complex lighting kit and the remote location meant we needed battery powered lights. In addition I knew before we left that there was a chance of bad weather so I needed lights that would work whatever mother nature decided to throw at us.

snw-scter-start-e1490980892561 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A snow scooter comes into the shot. You can see just how heavily it was snowing in this shot.

I decided to take a set of 3 Light & Motion Stella battery powered LED lights. It’s just as well I had the Stella lamps as on top of all the other difficulties of the shoot the weather decided it was not going to play ball. We had to shoot the scene (and much of the shoot) in the middle of a snow storm. Fortunately the Stella lights are completely waterproof, so I didn’t need to worry about rain or snow protection. Just set them up turn them on and use the built in dimmer to set the light output.

To light the scene I set up a Stella Pro 5000 in the woods behind the Sami tent, aimed through the trees and pointed directly towards the camera. I chose to backlight the trees to provide a sense of there being trees rather than lighting them. I felt this would look less lit than throwing a ton of light into the forest from the front and I’m pleased with the result.

20170317_201335-e1490980965481 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A Light & Motion Stella Pro 5000 was used to back light the trees and tent. The heavy snow was no problem as the light is totally waterproof.

The Stella Pro 5000 is very bright for a compact battery operated light, it’s 5000 lumen 120 degree output that is pretty close to what you would get from a 200W HMI, it’s very bright. It has a very high CRI and gives out great quality daylight balanced light.  It was positioned so that the light itself was behind the tent on a small bank, about 20m back in the woods. You couldn’t see it in the shot, but the light coming through the trees created shafts of light in the snow and the trees appeared as silhouettes. It added depth and interest to what would have otherwise been a near totally black background.

20170317_203855-e1490981224538 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
Light & Motion Stella 2000 used to light the forground, again the lamp is waterproof so bad weather is no problem.

Then to provide a small amount of light so that we could see the riders of the snow scooters as they walked to the tent I used a Stella 2000. I didn’t really want the light from this lamp to be too obvious as this would really make the scene look “lit”. I didn’t need the full 2000 lumen output so I used the built in dimmer to reduce the output to around 70%.

The third light was a small Stella 1000 and this was placed inside the tent with a scrunched up orange gel. The Stella 1000 would typically be used as a camera top light, but it’s full dimmable and produces a very high light quality, making it suitable for many applications. The creases and folds in the orange gel helped break up the light a little creating a less lit look sympathetic to the fire inside the tent.

in-tent-mid-e1490981340247 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A Stella 1000 with orange gel was used inside the tent to give the light from the fire a small boost.

It allowed me to increase the illumination in the tent, adding to the light from the fire without it being obvious that the tent interior was lit. For some of the shots I had an assistant sit in the tent, out of shot and slowly move the gel in front of the light to add a little movement to the light to mimic the firelight even better.

sihuette-e1490981444887 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
One particular shot on the storyboard was the silhouette of the drivers entering the tent. The Stella 1000 really helped punch trough the canvas sides of the tent.

At the moment I can’t show you the footage. That will have to wait until after the launch of the TV. But I’m really pleased with the way this scene came out. It’s challenging trying to shoot in the dark, in a blizzard, in temperatures well below freezing. Every aspect of getting this scene was hard. Opening a flight case to get out some kit meant getting snow on everything inside it. Just positioning the light up the woods was tough, the snow was up above my knees as I waded through it. Operating the camera is so much harder when it has a rain cover on it. The viewfinder was constantly misting up as snow fell on it non stop. Seeing the witness marks on the lens is difficult (although thankfully the marks on the Fujinon 20-120 are huge and easy to see).

20170317_205922-e1490981701785 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
The Fujinon Cabrio XK6X20 lens all iced up at the end of the day. After shooting out in sub zero temperatures don’t take the camera inside until you are sure you have wrapped for the day!

But sometimes it’s challenges like these that make the job interesting. I know I was cursing and swearing at times trying to make these shots work, but seeing the scene come to life in the grade is all the more rewarding.

I’ll be writing more about the Fujinon 20-120 very soon, so why not subscribe to my blog using the subscribe bottom on the left.

PW-FS5 and PXW-Z150 to get Hybrid Log Gamma for direct HDR production.

For the full details please see the official Sony announcement: https://www.sony.co.uk/pro/press/pr-sony-expands-hdr-production-capabilities

The PXW-FS5 and PXW-Z150 will both get a free firmware update some time around June that will add the ability to shoot using a special gamma curve called “Hybrid Log Gamma” or HLG.

In the case of the FS5 this will be added through an additional picture profile, PP10. As well as HLG the camera will also have the ability to record using Rec2020 color. As a result the camera will become compatible with the new Rec2100 standard for HDR television.

In addition the FS5 will get the ability to change the base ISO for S-Log2 and S-Log3 from 3200 ISO to 2000 ISO. This will help produce cleaner images that are easier to grade. On top of that via a paid firmware update you will be able to shoot continuously at up to 120fps in full HD, no need to use the Super Slow Motion memory cache function.

These are all great upgrades for this little highly versatile camera.

By selecting Picture Profile 10  the camera will shooting using Hybrid Log Gamma. If you were to plug the camera into an HDR TV that supports HLG then what you would see on the TV would be a HDR image with an extended dynamic range. This should give brighter more realistic highlights and a quite noticeable increase in overall contrast compared to SDR (Standard Dynamic Range). There will be no need to grade the footage to get a perfectly watchable vibrant HDR image. The real beauty of HLG (developed by the BBC and NHK) is that it is backwards compatible with normal SDR (Standard Dynamic Range) TV’s. So feed the very same signal into a conventional SDR TV and it will look just fine. Skin tones will be a touch darker than with Rec709 and  it won’t be HDR, but it will be perfectly watchable picture and most people won’t realise it’s anything different to normal SDR TV.

So HLG provides a simple very fast, direct HDR workflow that is backwards compatible with SDR TV’s. As a result you don’t need any special monitors to shoot with it, you can just monitor with existing SDR monitors, although it would be beneficial to have an HDR monitor to check the HDR aspect of the signal. HLG isn’t designed to be graded, although a little bit of post production tweaking can be applied, just as with Rec709.  Bottom line is it’s quick and easy, no special monitors or skills needed – simples.

If you want the very best possible HDR then you should shoot with S-Log2/S-Log3 or raw and then grade the material in post using an HDR capable monitor.  But that takes time and large HDR monitors are not cheap (for a small monitor you could use an Atomos Flame or Inferno).  The FS5 will give you the ability to work either way. HLG for simple and quick, S-Log for the best possible image quality.

Hopefully we will see HLG rolled out to other cameras in the near future.

ISO Confusion Once Again!

I’m going to keep bringing this up until people start to take note and understand that with an electronic camera ISO is NOT sensitivity.

With an electronic camera ISO is a guide to the required shutter speed and aperture needed to get the correct exposure. This is different to sensitivity. The ISO rating of a video camera and it’s sensitivity are closely related, but they are not quite the same thing. Because different gamma curves require different exposures the ISO rating for each gamma curve will be different even though the gain and actual sensitivity of the camera may be exactly the same.

Lets take the  Sony PXW-FS5 as an example.

If you shoot using the standard camera settings you should expose white at 90%, middle grey will be around 42% and skin tones typically around 70%. At 0dB gain the camera the camera will display an ISO equivalent rating of 1000 ISO. So let’s say you are using a light meter. You set it to 1000 ISO and it tells you you need an aperture of f5.6 to get the right exposure.

Now you change to S-Log2. If you do nothing else your white card will now be at around 75% and middle grey will be around 40%. At 0dB gain the camera will show an equivalent ISO of 3200 ISO.

But hang on – The camera is still at 0dB gain, so there is no change in sensitivity. .But the camera is over exposed, S-Log2 is supposed to be exposed with white at 59% and middle grey at 32%.

So we go to our light meter and change the ISO on the light meter from 1000 ISO to 3200 ISO. Because the light meter now “thinks” the camera is more sensitive by almost 2 stops it will tell us to close the aperture by nearly 2 stops. So we go to the camera and stop down to f10 and bingo, the image is exposed correctly.

But here’s the important thing – The camera hasn’t become any more sensitive. We haven’t replaced the sensor with a different, more sensitive one (as you would do with a film camera where you actually change the film stock). We are still at 0dB gain (even though the camera tells us this is the equivalent to a higher ISO).

The only reason that ISO number changes is so that if we were using an external light meter we would get the recommended exposure levels for the gamma curve we are using. In this example closing the aperture increase the highlight range that the camera would be able to cope with and this helps us get that full 14 stop range from the camera, although closing the aperture means less light on the sensor so the pictures end up a little noisier as a result – That is unless you choose to rate the camera at a different ISO by over exposing the log a bit.

ISO is useful, but you need to understand that it isn’t really sensitivity. After all we can’t change the sensors on our video cameras and that would be the only way to truly change the sensitivity. Any “sensitivity” change is really nothing more than a gain or amplification change. Useful but not the same as changing the actual sensitivity. Gain will make a dark picture brighter but it won’t allow you to see something that the sensor can’t detect.

It is much easier to understand dB gain with an electronic camera as it actually tells you exactly what the camera is doing and it is actually my recommendation that people use gain rather than ISO for all of the above reasons.  The use of ISO on electronic cameras is very badly understood, in part because it’s a largely meaningless term because it doesn’t tell us how sensitive the sensor is, how much gain we are using or how much noise we are adding. Give any experienced camera operator a camera and ask them how noisy will it be a 18dB gain and they will have a pretty good idea of what the pictures will look like. Give them the same camera and ask them how noisy will it be at 8000 ISO and they won’t have a clue.

The problem is ISO is trendy and fashionable as that’s what “cinematographers” use. But lets be honest with ourselves – we are using electronic video cameras, whether that’s a Red, Alexa or FS5 so really we should be using the correct terminology for an electronic camera which is gain. It would eliminate an aweful lot of confusion and tell us how much noise and grain our pictures will have. It’s noise and grain will levels will determine how good a clip looks and how much we can grade it, so we need to clearly understand how much gain is being added in camera and dB gian tells us this. ISO does not.

Side Note: Modern film stocks will often have 2 ratings, the ISO or actual measured sensitivity of the film stock plus the EI or Exposure Index which is the recommended setting for the light meter to get the best exposure. In some respects the ISO rating of a video camera is closer to the EI rating of a film stock. Perhaps we should stop calling it ISO and use the term EI instead, this would be me appropriate and signify that it is a reference for best exposure rather than true sensitivity.

UPDATE: A comment on facebook was why not display both ISO and Gain side by side. This is an obvious solution really. Why do camera manufacturers force us to choose either ISO or gain? Why can’t we use a hybrid of the 2? I see no technical reason why cameras can’t show both the gain and ISO at the same time – Problem solved.

Sony naming system

Here’s a little insight into what some of the Sony product prefixes might mean. These may not be 100% correct but this is what I understand them to mean. There are also many exceptions to the standard naming convention, so use this as a guide only.

First letter: P = Professional, B = Broadcast, U = Utility,  D = Digital, H = Studio/OB,  L = LCD, O = Optical

Second letter: V = Video (means video tape if camera), M = SxS Memory, D = Optical Disc, X = XQD/SD/SxS(solid state media or digital workflow), S = System, D = Multi format, P = Projector or Printer, R = Remote Control, W = wireless

Third letter: (or 3 + 4th): W = Writer( deck or camera that can also record/camcorder), M = Monitor, C = Camera(no recording capability) CU = Camera Control Unit, CP = Compact camera(no recording), X = HD, Z = 4K, D = Digital (HDSDI?),  A = Archive

Then after the 3/4 letter prefix: F = Film (digital cinema, 16 bit raw when raw included), FS = Film Style (large sensor, 12 bit raw when raw included), X = HD from factory (often but not always upgradable to 4K) , Z is 4K from factory.  NX = AVCHD

The number of digits after the letters used to be significant. 2 digits was a product without an imager (PMW-50, PMW-EX30) 3 digits was a camera (PMW-200, PMW-500) and 4 digits was a deck (PMW-HD1500, F1600). However recently cameras have any number of digits.

 

For example PXW-X200:

P = Professional   X = Solid state media   W = Writer –  X = HD camcorder.

Example BVW-400 (Betacam SP camcorder – remember those!)

B = Broadcast  V = Video Tape  W = Writer

Example PXW-FS7

P = Professional X = Solid State Media  W = Writer – FS = Film Style.

Example PMW-F55 (Slight odd-ball this one as it was the very first XAVC camera, perhaps should really have been a PXW-F55 although as it’s SxS and has the XDCAM codec PMW works too).

P = Professional  M = SxS Memory  W = Writer – F = Film (Digital Cinema).

Example PDW-700 (Optical disc camcorder)

P = Professional  D = Disk  W = Writer.

Example PMW-300

P = Professional  M = SxS Memory W = Writer.

Some oddballs:

F65 = F65 Ultimate digital cinema camera, no prefix and a 35mm sensor, not 65mm as the name suggests. Other “F” only cameras used the sensor size for the name. The F35 had a super 35mm sensor and F23 which had a 2/3″ sensor.

CBKZ = Software upgrade option.

CBK = Camera build kit

HDW = HDCAM Writer.

SRW = HDCAM SR Writer.

DSR = Digital DVCAM camera/camcorder/deck.

I don’t know what the HXR prefix stands for, this line of normally AVCHD solid state camcorders used to come from a different group within Sony to the broadcast group. These two groups now work together so the product numbering is now more consistent, but there are still many product names that don’t follow the convention.

It’s interesting to note that there are very few “Broadcast” B** products these days except for BVM (Broadcast Video Monitor) monitors. Most camcorders are now P** even if they are most definitely broadcast cameras, for example the PXW-X500.

If anyone would like to add to this list or correct any errors please let me know by adding a comment. Any input/additions are most welcome!

Auto Knee when shooting with Rec-709.

Like many cameras the Sony PXW-FS7, PMW-F5 and F55 use an automatic knee circuit to help the camera handle strong highlights or overexposure when shooting using standard gamma curves such as Rec-709 (STD gamma 5). On some ENG cameras there is a very similar function  called DCC (Dynamic Contrast Compensation) which is often selected via the Camera/Bars switch.

On the FS7, F5/F55 and many others the Auto Knee is on by default out of the factory. It can be turned on and off in the cameras paint settings. In most normal shooting situations, if you are correctly exposed the auto knee does a good job of bringing bright highlights down out of clipping.  The auto knee threshold is at around 90% brightness. Expose with objects brighter than 90% in your scene and the auto knee starts to kick in.

The correct exposure for white, such as a 90% reflectivity white card or white piece of paper in Rec-709 is 90%. Skin tones, plants, walls, roads and in fact most objects will normally be below white or below 90%. However direct light sources, such as the sky or direct reflections such as shiny car body work will be brighter than white. So the knee should only ever effect objects brighter than white if you are exposed correctly.  So for most situations it should not effect skin tones and the majority of the scene, just the bright highlights.

The auto knee detects highlight levels above 90% and tries to keep the highlight range below clipping by adding contrast compression to the highlights. The amount of compression depends on how strong the highlights are. As a result the auto knee effect will vary with exposure. If you have a scene with only a few highlights there will be some knee compression and it’s effect will only be seen above approx 90%. If you then open the aperture or have a lot of highlights the auto knee will increase the highlight compression to compensate. If the highlight range becomes very large then the knee will not only increase the amount of compression but also lower the knee point so more and more of the upper exposure range is effected by the knee. In extreme cases the knee point may get as low as 70-80% and this then starts to effect skin tones.

To prevent rapid fluctuations of the contrast in the highlight range the auto knee has a slight delay. This can result in a vicious circle where you open the iris a bit to help brighten the shot. The shot gets brighter. Then a couple of seconds later you look at the shot again and because the knee has now adjusted the highlights after it’s delay period it looks different to how it looked at the moment you made the initial adjustment. So you adjust again…. then the knee adjusts again and so on. Sometimes this lag can make it tricky to get your highlights to look exactly how you want.

Another common auto knee effect is to see the brighter parts of an entire image change as a result of a change in only a small part of the scene. A typical example would be an interview with a window in the background. As the highlight level in the bright window changes, perhaps as the sun comes and goes from behind passing clouds, the knee tries to compensate and all of the highlights in the scene go up and down in brightness whether they are over exposed or not. This looks very strange and can ruin an otherwise good looking shot.

If you are shooting in a studio against a white background the auto knee makes it impossible to get a brilliantly bright uniformly clipped white background. You increase your exposure to make the white background extra bright and because that white is now above 90% the auto knee treats it as a highlight and tries to control it’s brightness. The more you open the aperture the more the knee pulls down the white background, it never reaches clipping. Eventually you get to the point where the knee starts to effect the skin tones but your white backdrop still isn’t clipped. The image doesn’t look great.

In these cases the best thing to do is to turn off the Auto Knee. If you go into the paint settings you will find the knee settings. In most cases leave the knee on (except perhaps for the white studio example), but turn OFF the auto knee function. The fixed level knee will still give you a good highlight range but eliminate the pumping or other variable knee effects. Note that the knee options have no effect if using a Hypergamma or log. They only come into paly with standard gamma.

Raw and the PXW-FS5

This isn’t a “how to” guide. There are many different recorders that can be used to record raw from the FS5 and each would need it’s own user guide. This is an overview of what raw is and how raw recording works to help those that are a bit confused, or not getting the best results.

First of all – you need to have the raw upgrade installed on the FS5 and it must be set to output raw. Then you need a suitable raw recorder. Just taking the regular SDI or HDMI output and recording it on an external recorder is not raw.

Raw is raw data direct from the cameras sensor with very little image processing. It isn’t even a color image, it won’t become color until some external processing, often called “De-Bayer” is done to convert the raw data to a color image.

For raw to work correctly the camera has to be set up just right. On the FS5 you should use Picture Profile 7. Don’t try and use any other profile, don’t try and shoot without a profile. You must use Picture Profile 7 at it’s factory default settings. In addition don’t add any gain or change the ISO from 3200. Even if the scene is a dark one, adding gain will not help and it may in fact degrade the recorded image.

White balance is set using the appropriate SGamut + color temperature preset chosen from within Picture Profile 7, there are only 3 to choose from for S-Gamut, but with a raw workflow you will normally fine tune the white balance in post. No other color matrix or white balance method should be used. Trying to white balance any other way may result in the sensor data being skewed or shifted in a way that makes it hard to deal with later on.

All of the above is done to get the best possible, full dynamic range data off the sensor and out of the camera.

If you are viewing the S-Log2 (ie don’t have viewfinder gamma assist enabled) then the exposure level that Sony recommend is to have a white card at 60%. So consider setting the zebras to 60%. Don’t worry that this may look a bit dark or appear to be a low level, but that’s the level you should start with… More about exposure later on.

This raw data is then passed down the SDI cable to the external recorder. The external recorder will then process it, turn it into a color signal (de-bayer) and add a gamma curve so that it can be viewed on the recorders screen. Exactly what it will look like on the monitor screen will depend on how the recorder is set up. IF the recorder is set to show S-Log2, then the recorders screen and the FS5’s LCD should look similar. However you might find that it looks very different to what you are seeing on the FS5’s LCD screen. This is not unexpected. If the recorder is setup to convert the raw to Rec-709 for display then the image on the recorder will be brighter and show more contrast, in fact it should look “normal”.

Under the surface however, the external raw recorder is going to be doing one of two things (normally at least). It’s either going to be recording the raw data coming from the camera as it is, in other words as raw. Or it will be converting the raw data to S-Log2 and recording it as a conventional ProRes or DNxHR video file. Either way when you bring this footage in to post production it will normally appear as a flat, low contrast S-Log2 image rather than a bright, contrasty rec-709 image. So understand that the footage will normally need to be graded or have some other changes made to it to look nice.

Recording the actual raw data will give you the best possible information that you can get from the FS5 to work with in post production. The downside is that the files will be huge and will take a fair amount of processing power to work with. Recording a ProRes or DNxHR video file with S-Log2 gamma is second best. You are throwing away a bit of image quality (going from 12 bit linear down to 10 bit log) but the files should still be far superior to the 8 bit UHD internal recordings or even an external recording done via the HDMI which is also limited to 8 bit in UHD.

Most raw recorders have the ability to add a LUT – Look Up Table – to the image viewed on the screen. The purpose of the LUT is to convert the S-Log2/raw to a conventional gamma such as Rec-709 so that the picture looks normal. If you are using a LUT then the normal way to do things is to view the normal looking picture on the recorders screen while the recorder continues to record S-Log2 or raw. This is useful as the image on the screen looks normal so it is easier to judge exposure. With a 709 LUT you would expose the picture so that the image on the recorders screen looks as bright as normal, skin tones would be the usual 70% (ish) and white would be 90%.

There is a further option and that is to “bake in the LUT”. This means that instead of just using the LUT to help with monitoring and exposure you actually record the image that you see on the recorders screen. This might be useful if you don’t have any time for grading, but… and it’s a big BUT…. you are now no longer recording S-log2 or raw. You will no longer have the post production grading flexibility that raw or S-Log2 provide and for me at least this really does defeat the whole point of recording raw.

Exposure: Raw will not help you in low light. Raw needs to be exposed brightly. If viewing S-Log2 then Sony’s recommendation is to have a white card or white piece of paper at 60%. I consider that to be the absolute minimum level you can get away with. The best results will normally be achieved if you can expose that white card or piece of paper at around 70% (when looking at an S-Log2 image). Skin tones would be around 55%. If you expose like this you may need to use a different LUT on the recorder to ensure the picture doesn’t look over exposed on the recorders monitor screen. Most of the recorders include LUT’s that have offsets for brighter exposures to allow for this. Then in post production you will also want a LUT with an exposure offset to apply to the S-Log2 recordings. You can use the search function (top right) to find my free LUT sets and download them.

SEE ALSO: https://www.sony.co.uk/pro/article/broadcast-products-FS5-raw-shooting-tips

 

Camrade PXW-FS7 and PXW-FS7 II rain covers.

I was recently sent a new rain cover by Camrade for my FS7 (there is also one for the FS7 II). I’ve used Camrade “wet suits” as they call them for years. They are great covers made from a low noise fabric. That means that if you need to fiddle with the cover while shooting it makes very little noise. The fabric is high quality, soft and supple but also completely waterproof.

AJC03783-1024x683 Camrade PXW-FS7 and PXW-FS7 II rain covers.
Camrade “wet suit” rain cover for the PXW-FS7

The FS7 cover set covers the whole camera and lens and also has a separate cover for the viewfinder that can be used either with the extension tube attached or thanks to a large clear panel that allows you to clearly see the LCD screen it can be used without the extension tube. There is also a cover for the arm and handgrip.

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The Camrade FS7 rain cover kit includes a cover for the viewfinder.
AJC03794-1024x683 Camrade PXW-FS7 and PXW-FS7 II rain covers.
The Camrade cover can be used with or without the viewfinder extension tube.

The main camera body cover has clear panels that allow you to see all the major controls and switches on both sides. In addition the clear panels can be opened and rolled up and secured open by velcro  if you want easy access to the camera while it’s not raining.

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Clear panels can be rolled up and secured for easy access to the camera on the Camrade rain cover.

Along the top of the cover there is a long velcro opening that allows the mount for the viewfinder to exit the cover as well as an elasticated opening for a shot gun mic. There are further openings for the front MI shoe as well as the cameras top handle.

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The Camrade FS7 rain cover has an elasticated sleeve for a shotgun mic there plus opening for the front shoe of the FS7.

Overall the cover is quite large and the fit is quite baggy on a bare bones FS7. But this does mean that you can attach radio mic receivers or timecode sync boxes etc to the camera and keep them protected from the elements under the cover.  The bagginess also allows you to grip the top handle through the rain cover, so even when carrying the camera from location to location it remains protected from the elements.

The length of the cover means that there is space at the back for the XDCA extension unit and/or an external battery system. There’s even a little flap at the back that allows you to see the top of the battery to check the batter status. This is great with my PAG-Link batteries (love my PAG-Links).

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There are access panels and flaps just where you need them on the Camrade FS7 rain cover.

If you are using a long lens then you can add an included extension section to the front of the cover that will protect most lenses. Underneath the main cover there is a zip that allows you to almost completely close the rain cover so that when using the camera on your shoulder it doesn’t flap about.

Cameras like the FS7 are expensive. While the FS7 does have a degree of built in protection against a splash of water it really isn’t designed to survive a heavy rain shower. The Camrade covers are not expensive and much better than wrapping the camera in a bin bag. When not in use the cover slips into a nice soft pouch that you can keep in your camera bag until the next time you need it.

Sony FDR-X3000 4K Action Cam – built in gimbal.

One of the cameras I used a lot in Norway is the new Sony FDR-X3000 action cam. What’s different about this POV camera is that the lens and sensor are actually mounted in an internal miniaturised gimbal. This really does work and helps stabilise the image.

There is also a tiny bluetooth monitor that you can wear on your wrist to view the pictures and control the camera. The image quality you get from these tiny cameras really is quite amazing. Take a look at the video to find out more and see some sample footage.