For some reason many people now believe that the only way you can shoot with S-Log3 is by “over exposing” and very often by as much as almost 2 stops (1.7 stops is often quoted).
When Sony introduced the original A7S, the FS5, F5, F55 and FS7 shooting S-Log3 with these cameras was a little tricky because the sensors were quite noisy when used at the relatively high base ISO’s of these cameras. When exposed according to Sony’s recommendation of 41% for middle grey and 61% for a white card the end result would be fairly noisy unless you added a good amount of post production noise reduction. As a result of this I typically recommended exposing these particular cameras between 1 and 2 stops brighter than the base level. If using the F5 or FS7 I would normally use 800EI which would lead to an exposure +1.3 stops brighter than base. This worked well with these cameras to help control the noise, but did mean a 1.3 stop loss of highlight range. In other examples I used to recommend exposing a white card at white at 70% which would equate to an exposure a touch over 1 stop brighter than the base level.
With the introduction of the original Venice camera and then the FX9 we got a new generation of much lower noise sensors with dual base ISO’s. It soon became clear to me that these new cameras didn’t normally need to be exposed more brightly than the Sony recommended levels when using their low base ISO’s and even at their high base ISO’s you can typically get perfectly acceptable results without shooting brighter, although sometimes a small amount of over exposure or a touch of noise reduction in pots might be beneficial. No longer needing to expose more brightly brought with it a useful increase in the usable highlight range, something the earlier cameras could struggle with.
Then the A7S3, FX6 and FX3 came along and again at the lower of their base ISO’s I don’t feel it is necessary to shoot extra bright. However at the 12,800 high base ISO there is a fair bit more noise. So I will typically shoot between 1 and 2 stops brighter at the high base ISO to help deal with the extra noise. On the FX6 and FX3 this normally means using between 6400 and 3200 EI depending on the scene being shot.
Even though I and many others no longer advocate the use of extra bright exposures at the lower base ISO’s with these newer cameras it really does surprise me how many people believe it is still necessary to shoot up to 2 stops over. It’s really important to understand that shooting S-Log3 up to 2 stops over isn’t normal. It was just a way to get around the noise in the previous cameras and in most cases it is not necessary with the newer cameras.
Not having to shoot brighter means that you can now use the Viewfinder Display Gamma Assist function in the A7S3, A1 or the FX9 (for those times you can’t use a LUT) to judge your exposure with confidence that if it looks right, it most likely will be right. It also means that there is no longer any need to worry about offset LUT’s or trying to correct exposure in post before applying a LUT.
Of course, you can still expose brighter if you wish. Exposing brighter may still be beneficial in scenes with very large shadow areas or if you will be doing a lot of effects work. Or perhaps simply want an ultra low noise end result. But you shouldn’t be terrified of image noise. A little bit of noise is after all perfectly normal.
And one last thing: I don’t like the use of the term “over exposing” to describe shooting a bit brighter to help eliminate noise. If you have deliberately chosen to use a low EI value to obtain a brighter exposure or have decided to expose 1 stop brighter because you feel this will get you the end result you desire this is not (in my opinion) “over exposure”. Over exposure generally means an exposure that is too bright, perhaps a mistake. But when you deliberately shoot a bit brighter because this gets you to where you want to be this isn’t a mistake and it isn’t excessive, it is in fact the correct exposure choice.
Category Archives: FX6
Using The S-Log3 LUT To Bake In The EI
Many people wish to bake in the cameras Exposure Index settings when shooting using CineEI in order to avoid having to make an exposure correction in post production (given that the cameras are ISO invariant when shooting Log in reality it makes vey little difference whether you add gain in the camera or in post production – gain is gain). On cameras such as the FS7, FX6 or FX9 one way to do this is by baking in the built in S-Log3 LUT. To avoid confusion – that is using the CineEI mode with the “S-Log3” LUT enabled and in the LUT settings “Internal recording” set to ON so that you are recording the “S-Log3” LUT.
While this will bake in the EI change, this technique comes with many issues. For a start, just as when you use S-Log3 in custom mode and alter the ISO, whenever you move away from the cameras base ISO you loose dynamic range. When you bake in a LUT and change the EI, you are in effect changing the ISO and there will be a corresponding loss of dynamic range. When you bake in a LUT this loss of dynamic range is exacerbated by a reduced or altered recording range.
At lower EI’s the available recording range shrinks as the LUT is made darker and at the same time upper recoding level of the LUT is reduced. At 200 EI the recording range only gets to around 78%. At the bottom end the shadows are crushed and shadow information lost by the range reduction. This then causes a post production issue because LUT’s designed for the normal S-Log3 input range of 0-94% will now be applied to recordings with a much reduced range and after application of a LUT in post the final output won’t get to 100% without further complex grading where the image will need to be stretched more than normal and this degrades quality.
At high EI’s the LUT becomes brighter but the clip point remains the same. So for each stop you go up, 1 stop of highlights just disappears beyond the LUT’s hard clip point and can’t be ever recorded. Again in post this can cause issues because when you apply a normal S-Log3 LUT the heavy clipping in the recording causes the highlights to look very heavily clipped (because they are). Again, for the best results you will need to grade your footage to allow for this.
So, in practice the idea of baking in the S-Log3 LUT to eliminate the need to do any post production corrections doesn’t work because the addition of the S-Log3 LUT introduces new limitations that will need to be corrected if you want good looking images. Plus adding the S-Log3 LUT in camera and then adding another LUT on top in post is never going to deliver the best results due to the way LUT’s divide the image into brightness zones.
And – if you are baking in the S-Log3 LUT, then really this is no longer EI as there is now no longer an offset between the exposure and the recording, you are simply recording at a higher/lower ISO.
Use GyroFlow to stabilise Sony (and other camera) footage.
Sony’s Cinema Line cameras all have the ability to record metadata from inertia and gyroscope sensors about the way the camera moves while shooting. This metadata can then be used to stabilise your footage in post production. The stabilisation that this can provide is normally very good and tends to look a lot more natural than using post production stabilisation that looks at the footage and tries to hold it steady. However, until recently the only way to make use of this metadata was via Sony’s Catalyst Browse software.
Now however an Open Source project known as GyroFlow has made it possible to use the Sony metadata in FCP-X and DaVinci Resolve via an OpenFX plugin and a FCP-X plug-in. In addition there is a standalone GyroFlow application that can stabilise the footage and then export a stabilised version of the clip.
GyroFlow is a collaborative Open Source project, so different developers are working on different aspects and plug-ins, so it is a bit more disjointed than a lot of commercial products. But, it is free and it will get better, so why not give it a try. The main website for the project is here: http://gyroflow.xyz/
FX6 and FX9 R and B Gain values – don’t worry about the odd numbers.
I’ve noticed some users concerned or confused by the R and B gain values that they see in the cameras white balance settings after dialling in a custom white balance and tint, or after taking a white balance from a white card. The R and B gain values indicate the offset that is being applied to the Red and Blue channels relative to the Green channel and in fact they are perfectly normal.
Typically the concern occurs when someone has used a white card to set their white balance and then these seemingly random numbers appear against the Red and Blue gain. But they are not random, they are expected, normal, and not normally something to every worry about.
The FX6 and FX9 are set up such that the indicated Red and Blue gains will only ever both be 0 when the white balance of the camera is at exactly 3200K. At any other white balance there will be an offset to the R and B gain – and that is completely normal. It is these offsets that balance the Red and Blue levels so that the white balance appears correct. At a lower colour temperature you will see a positive blue value and a negative red value. Above 3200K there will be a positive Red value and a negative Blue value. A positive tint value will make both the Red and Blue more positive and a negative tint value will make both the Red and Blue values more negative.
All of this is perfectly normal and perfectly expected. If you have taken a white balance off a white card and then dial in a preset value you might find that the you can’t get the last 2 digits back to a zero.
For example after white balancing off a card you have 3653K but you then try to dial in 3200K, but the closest you can get is 3193K or 3213K. This is because the smallest steps the colour temperature changes in is 20K (on the FX6 above 5640K the steps gradually get larger and larger). But this really isn’t something to worry about 3193K or 3213K are both so close to 3200K that either will do and calibration and temperature differences will mean that the actual variations between different cameras or the camera and a colour meter will be greater than this error anyway. No two cameras will ever be truly identical and differences between lenses will cause add to this normal variation. There is no need to worry about the last 2 digits not being zero’s.
At the end of the day, these tiny differences are not something to worry or be concerned about. But if you do want to return the last digits back to zero you can do this by dialling the white balance all the way down to 2000K.
Bright Tangerine Rigging Options for the FX6
Bright Tangerine are a UK manufacturer of very high quality camera accessories such as matte boxes, base plates etc. They are based not far from me and I have know them for many years. They also happen to be a sponsor of this site. They may not be a company that some of you have come across before as traditionally their products have been aimed at high end users of cameras such as Venice as well as the Arri and Red digital cinema cameras. But they are now producing some very nice products for lower cost cameras such as the Sony FX6.
Starting at the top of the camera we have a very nice top plate with an optional center section. The center section as well as the sides sections of the cheese plate are all Nato rail compatible and you can attach a Nato rail handle should you wish to use a different handle to the sony one. Like the majority of Bright Tangerine products the 1/4″ and 3/8″ holes are fitted with stainless steel inserts and are surrounded by holes to the Arri anti-rotate standard.
Moving to the side of the camera there is the option to attach a side plate to the top plate. This side plate provides plenty of mounting space for things like radio mics or timecode boxes. It is mounted sufficiently far from the side of the camera body that the SDi and HDMI connectors are still easily accessible but not so far out that it gets in the way with the handgrip.
Viewfinder attachment and bracket.
Bright Tangerine make a very nice viewfinder bracket that replaces the Sony one as well as a support system for the LCD screen that eliminates the sagging issues that typically occurs if you want to add a loupe or magnifier to the LCD screen. The LCD bracket uses a clever folding nato rail design that makes it easy to move the mounting point forwards and backwards as well as up and down.
As well as attaching to the Sony handle the mount has an extra support piece that goes down to the Bright Tangerine top cheese plate. This extra support piece not on helps to support the LCD bracket but it also helps to stabilise the Sony handle.
Viewfinder support System.
The viewfinder support system includes a frame that the LCD attaches to that has a fluid damped tilt mechanism. An easy to grip orange knob is used to adjust the tilt tension of the viewfinder.
When supported by this bracket it is very easy to use an additional viewfinder magnifier or loupe. One of the nice features of the Bright Tangerine FX6 viewfinder support is that it still allows the LCD to be folded flat against the side of the camera when it is not in use.
Left Field Base Plate.
Moving to the bottom of the camera and we have the Bright Tangerine Left Field base plate system. This is quite different to most other base plates. It doesn’t use a VCT plate and as a result it doesn’t suffer from the almost inevitable slight play and wobble that comes with most VCT based systems (perhaps the only exception to this is the Chrosziel QuickLok plate). Instead of using a VCT plate it mates with a standard sized Arri dovetail plate or with Bright Tangerines own light weight dovetail plates.
The Left Field has a very secure clamping system that uses a single lever to clamp and release the plate from the dovetail quickly and easily. When releasing there is an initial lock catch that is released to open the latch and at that point the base can be slid along a normal dovetail plate but won’t lift off or fall off it. To fully release there is a second push button at the base of the release lever that allows the clamp to be completely released and then the camera just lifts off the dovetail.
Once you have used it a couple of times you can release the camera in one single motion by pressing the release button as you open the catch. But it can’t accidentally come undone. To attach the camera to a dovetail you simply slot it on to the far side of the dovetail, and then close the catch, it’s very quick and very easy. The Left Field system creates a very low profile, very stable mounting platform for you camera. Being low profile, when using a tripod it keeps the cameras center of gravity lower allowing you to use less counterbalance and keeps the lens closer to the tilt pivot point.
If you want to add a shoulder pad, one of Bright Tangerines very clever Kasbah pads can be attached to the back of the plate via a quick release bracket. The Kasbah pad is constructed out of a special material that allows the internal structure to be varied to allow for differing levels of firmness across the pad. This makes it very comfortable while offering very stable shoulder support.
BUT when the Kasbah pad is mounted to the rear of the very low profile Left Field it won’t then go on to a normal dovetail as the pad gets in the way. So, you have 2 options. One is to only mount the shoulder pad under the Left Field as and when you need it. The top of the Kasbah pad has a small Arri dovetail so it is very quick to attach to the Left Field. The other option is to use a small riser that raises the Left Field and shoulder pad clear of the dovetail.
One of the great things about the Left Field system is that should you ever change camera all you need to replace is a small mounting adapter that inserts into the top of the Left Field base plate. These means the same Left Field can be used with many cameras, protecting your investment.
I really like the bright Tangerine products. They are a little bit different, quirky perhaps. But it’s only by thinking outside of the box that we get new products that really do work. So, if you are looking for a cheese plate, base plate or LCD support system for your FX6 do at least take a looks at their offerings.
Improve the accuracy of manual white balance with the FX6 and FX9.
Have you ever struggled to get a decent white balance from a white or grey card with the Sony FX6, FX9 or in fact many other cameras (this method works equally well for the FS7, FS5, F5 and F55 etc)? Well here is a very simple trick that can really help, especially for those situations where the camera is a long way from the scene and a white card is too small in the frame for an accurate reading.
All you need to do is to cut a square hole in a piece of black card or plastic. Then when you want to take your white balance simply hold the mask in front of the lens so that it masks out the background of the shot leaving just your white card visible. It’s really simple, really easy and it really works!
New LUT for Sony cameras and S-Log3 – Elixir
I’ve added a new LUT for S-Log3 and SGamut3.cine to my free LUT collection. The new LUT is called Elixir and is the first LUT from a collection of 3 new LUTs with similar contrast and brightness but quite different colours that I will be releasing between now and the end of the year. Elixir is designed for short film projects and drama to provide rich colours with pleasing skin tones. Blues are shifted slightly teal, but there is no distracting colour cast, just pleasing colours with mid to high contrast. The LUT can be used with any Sony camera that has S-Log3 and SGamut3.cine, so that includes the whole of the Cinema Line including the FX6, FX3 and FX30 as well as cameras like the FS5 and FS7. For more information and to download this or any of my free LUTs please go to the LUT page: https://www.xdcam-user.com/picture-settings-and-luts/alisters-free-luts/
Removing Screws From Sony Cameras
Although I wouldn’t normally recommend removing the screws from Sony cameras there are times when this is something you need to do, for example to remove the microphone mount on an FX6.
Most of the small screws have a thread locking compound applied to the threads to prevent them from shaking or vibrating loose. This can make them hard to unscrew.
JIS NOT Phillips!!
The main issue is that most cross of the commonly found small and miniature head screw drivers are manufactured to the “Philips” standard. But the screws used on the Sony cameras are manufactured to the JIS standard. The differences between these two very similar looking standards means that you will not get a secure and tight fit between a Philips screw driver and a JIS screw head. The edges of a Philips screwdriver are at an angle that is too shallow to properly engage with the full depth of a JIS screw head. So when you try to undo a tight screw the head of the screw will deform or strip, often to the point where it can’t be undone.
Whenever working on Sony cameras you should use JIS standard screwdrivers and ensure the screwdriver is the correct size for the screws you are working with. The smaller screws used for thing like the microphone mount on the FX and Alpha series cameras are JIS size +0 or +00. A JIS size +0 seems to fit most but I would also get a +00.
Don’t try to use a miniature Philips screwdriver on a tight JIS screw. It might look like it fits, but only a very small part of the screwdriver head will be correctly engaged with the JIS screw and once the screw head is damaged you can’t undo the damage and it may become impossible to remove the screw without drilling it out.
If you search for “Vessel JIS” you should be able to find good quality small and miniature JIS screwdrivers on Amazon, ebay or from other suppliers.
Don’t Attach Extension Arms To the Side Of an FX6.
I attempts to turn the FX6 into a shoulder camera I am seeing a lot of people removing the FX6’s handgrip from the side of the camera and then attaching an extension arm to the camera body where the hand grip normally attaches, perhaps either directly with a dedicated arm or by fitting a rosette to the camera body.
I strongly recommend you do not do this!
A long arm increases the amount of force that can be applied to the body of the camera and it wasn’t designed to take the forces an arm places on it. Especially if the camera is loaded up with other accessories such as monitors, V-Lock adapters or a base plate. There have been several instances of the camera body fracturing around the hand grip mount when an extension arm has been used. Replacing the camera body is not cheap and it is unlikely to be covered under any warranty as it wasn’t designed to be used this way.
Instead mount the arm to a base plate, there are many FX6 base plates that include a suitable rosette for arms and other accessories.
Low Light Shooting – S-Log3 or S-Cinetone?
A fundamental aspect of electronic cameras is that the bulk of the noise comes from the sensor. So the amount of noise in the final image is mostly a function of the amount of light you put on to the sensor v the noise the sensor produces (which is more or less constant). This is known as the signal to noise ratio, often abbreviated to SNR.
Whether you use S-Log3 or S-Cinetone, even though the base ISO number the camera displays changes the sensitivity of the camera is actually the same, after all we are not changing the sensor when we change modes. In fact if you set the camera to dB you will see that in custom mode the base for both S-Cinetone and S-log3 (and every other gamma curve) is always 0dB.
All we are changing when we switch between S-Cinetone and S-Log3 is the gamma curve – which is a form of gain curve. The base ISO number changes between S-Log3 and S-Cinetone because if you were using an external light meter this would be the number to put into the meter to get the “correct” exposure, but the actual sensitivity of the camera remains the same.
First let’s think about what is happening at the base ISO of each if we were to use an external light meter to set the exposure…..
If we shoot at S-Cinetone and use the 320 ISO value in the light meter the aperture will be a little over a stop more open than if you shoot with S-Log3 and use 800 ISO for the light meter. So when using S-Cinetone at the base ISO there is a little over twice as much light going on to the sensor compared to S-Log3 at the base ISO and as a result the S-Cinetone will be much less noisy than the S-Log3. Not because of a sensitivity or noise performance difference but simply because you are exposing the sensor more brightly.
And if we use the SAME ISO value for S-Cinetone and S-Log3?
So now think about what might happen if you were to put 400 ISO into your light meter and use the values for shutter and aperture the meter gives and shoot with either S-Cinetone or S-Log3 using the very same aperture and shutter settings so that the same amount of light is hitting the sensor for both. The result will be that the amount of noise in the resulting image will be broadly similar for both and the same would happen if you were to use, let’s say, 4000 ISO (assuming you switch to high base for both).
There will tend to be a bit more noise in the S-Log and CineEI at the default settings, because by default NR is turned off in CineEI. But with the same in camera NR settings, again both the S-Log3 and S-Cinetone will have very, very similar noise levels when the sensor receives the same amount of light.
What about when there isn’t enough light?
So – when you are struggling for light, both will perform similarly from a noise point of view. BUT where there may be a difference is that with S-Cinetone all your image processing is done before it is compressed by the codec and what you see in the viewfinder is what you get. With S-Log3 the “underexposed” image gets compressed and then you will need to process that in post and when you add your post corrections this will be to the recorded image + compression artefacts so there will always be a lot of uncertainty as to how the final image will come out.
Personally I tend to favour S-Cinetone for under exposed situations. Generally if it’s under exposed dynamic range isn’t going to be an issue. S-Cinetone also spreads what image information you do have over a greater range of code values than S-Log3 and this may also help a little. But there is no right or wrong way and any differences will be small.