Tag Archives: FS5

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! 

Shooting Raw With The FS5 And Ninja V+

This came up in one of the user groups today and I thought I would repeat the information here.

One issue when using the Atomos Ninja V+ rather than an older Atomos Shogun or Inferno is that the Ninja V+ doesn’t have an internal S-Log2 option. This seems to cause some users a bit of confusion as most are aware that for the best results the FS5 MUST to be set to PP7 and S-Log2 as this is the only setting that fully optimises the sensor setup.
 
When you shoot raw, you are recording linear raw, the recordings don’t actually have any gamma as such and they are not S-log2 or S-Log3, they are raw. The S-Log2 setting in the FS5 just ensures the camera is optimised correctly. If you use the S-Log3 settings, what you record is exactly the same – linear raw, just with more noise because the camera isn’t as well optimised.
 
Any monitor or post production S-Log2 or S-Log3 settings are simply selecting the intermediate gamma that the raw will be converted to for convenience. So when the Ninja V+ states S-Log3 this is simply what the Ninja converts the raw to, before applying any LUT’s. It doesn’t matter that this is not S-Log2 because you didn’t record S-Log2, you recorded linear raw. This is simply what the Ninja V+ will use internally when processing the raw.
 
You have to convert the raw to some sort of gamma so that you can add LUT’s to it and as S-Log3 LUT’s are commonly available S-Log3 is a reasonable choice. With earlier recorders you had the option to choose S-Log2 so that when viewing the native S-Log2 output from the camera, what you saw on the monitors screen looked similar to what you saw on the FS5’s LCD screen when the FS5 was set to S-Log2. But S-Log2 is no longer included in the latest monitors, so now you only have the option to use S-Log3. But from an image quality point of view this monitor setting makes no difference and has no effect on what is recorded (the FS5 should still be set to PP7 and S-Log2).
 
In post production in the past, for consistency it would have been normal to decode the raw to S-Log2 so that everything match throughout your production pipeline from camera to post. But again, it doesn’t really matter if you now decode the raw to S-Log3 instead if you wish. There will be no significant quality difference and there is a wider range of S-Log3 LUT’s to choose from.
 
If the footage is too noisy then it is under exposed, it’s the only reason why the footage will be excessively noisy. It is true that raw bypasses the majority of the cameras internal noise reduction processes, but this only makes a small difference to the overall noise levels. 

Even with the latest Ninja V+ what is recorded when outputting raw from the FS5 is 12 bit linear raw.
 
12 bit Linear raw is a somewhat restricted format. 12 bits is not a lot of code values to record a high dynamic range linear signal. This is why most cameras use log recording for wide dynamic ranges, log is much more efficient and distributes the available recording data in a way very sympathetic to the way human vision works.
 
In practice what this means is that the 12 bit linear raw has LOTS of data and image information in the upper mid range and the very brightest  highlights. But relatively very little picture information in the lower mid range and shadows. So if it is even the slightest bit under exposed the image will degrade very quickly as for each stop yu go down in brightness you halve the amount of image information you have.
 
In an underexposed image the noise will be very coarse in appearance and the image will be difficult to grade. You really do need to expose the raw nice and bright and because of the way the data is distributed, the brighter you can get away with the better. Never be afraid of exposing linear raw “just a little bit brighter”. It is unlikely to severely bite you if you are over exposed but highly likely to bite you if it is even a fraction under.
 
The 12 bit linear raw from the FS5 is not going to be good in low light or when shooting scenes with large shadow areas unless you can expose bright so that you are bring your levels down in post. If you have to bring any levels up in post the image will not be good.
 
Raw is not a magic bullet that makes everything look great. Just as with S-Log it must be exposed carefully and 12 bit linear raw is particularly unforgiving – but when exposed well it is much better than the internal 8 bit log recordings of the FS5 and can be a fantastic format to work with, especially given the low cost of an FS5.
 
I recommend going back to basics and using a white card to measure the exposure. If monitoring the raw via S-Log3 the white card needs to be exposed around 70%. If using a light meter with the FS5 set the light meter to 640 ISO.
 
If you do want to use a LUT on the Ninja to judge your exposure use a LUT with a -1.5 stop offset. The darker LUT will encourage you to expose the raw brighter and you will find the footage much easier to grade. But it should also be considered that it is also quite normal to add a small amount of selective noise reduction in post production when shooting raw. 

Facebook Live – Streaming with the FS5.

Facebook Live stream Thursday 26th March 4pm GMT/UTC on how to stream to Facebook and YouTube with the Sony PXW-FS5 (also applies to many other Sony cameras with similar streaming options).
I will show you how to connect the camera to a network via Wi-Fi, how to send the stream from the camera to a computer. I will show you how to set up VLC to receive the stream from the camera and then how to use OBS to convert the FS5’s stream (via VLC) and send it to YouTube.
The “How To” live stream will be on my Facebook page: https://www.facebook.com/alister.chapman.9. But if you also have YouTube you will be able to see the stream from the FS5 once it is connected and setup. Links will be shared during the presentation.
If you install VLC: https://www.videolan.org/
Ahead of the session you should be able to set everything up as we go.
Thursday March 26th 16:00 GMT/UTC, 17:00 EU,  12:00 EDT,  9:00AM PDT.

Live Streaming From an FS5

Do you have an FS5 and want to stream to Facebook or YouTube? It’s actually fairly straight forward and you don’t even need to buy anything extra! You can even connect a couple of FS5’s to a single computer and switch between them.

How do you do it?

First you will need to download and install two pieces of free software on your computer. The first is VLC. VLC is an open source video player but it also has the ability to act as a media server that can receive the UDP video streams that the FS5 sends and convert them into a live video clip on the computer. The computer and the camera will both need to be connected to the same wifi network and you will need to enter the IP address of the computer into the streaming server settings in the FS5. By connecting the FS5 to your computer via the network you can use VLC to decode the UDP stream . Go to “file” “open network” and click on “open RTP/UDP stream” and enter the computers IP address and the stream port, you should then save the FS5 stream as a playlist in VLC.

The next piece of software that you need is OBS Open Broadcast Studio. 

OBS is a clever open source streaming application that can convert any video feed connected to a computer into a web stream. From within OBS you can set the signal source to VLC and then the stream from the FS5 will become one of the “scenes” or inputs that OBS can stream to Facebook, YouTube etc.

For multi-camera use a different port for each of the UDP streams and then in VLC save each stream as a different playlist. Then each playlist can be attached to a different scene in OBS so that you can switch. cut and mix between them.

 

Using different gamuts when shooting raw with the PXW-FS5

This topic comes up a lot. Whenever I have been in discussion with those that should know within Sony they have made it clear that the FS-Raw system is designed around S-Log2 for monitoring and post production etc. This stems from the fact that FS-Raw, the 12 bit linear raw from the FS700, FS7 and FS5 was first developed for the FS700 and that camera only had SGamut and S-Log2. S-Log3 didn’t come until a little later.

The idea is that if the camera is set to SGamut + S-Log2 it is optimised for the best possible performance. The raw signal is then passed to the raw recorder where it will be recorded. For a raw recorder that is going to convert the raw to ProRes or DNxHD the recorder converts the raw to S-SGamut + Log2 so that it will match any internal recordings.

Finally in post the grading software would take the FS-Raw and convert it to SGamut + S-Log2 for further grading. By keeping everything as SGamut and S-Log2 throughout the workflow your brightness levels, the look of the image and any LUT’s that you might use will be the same. Internal and external recordings will look the same. And this has been my experience. Use PP7 with SGamut and S-Log2 and the workflow works as expected.

What about the other Gamuts?

However: The FS5 also has SGamut3, SGamut3.cine and S-Log3 available in the picture profiles. When shooting Log many people prefer S-Log3 and SGamut3.cine. Some people find it easier to grade S-Log3 and there are more LUT’s available for S-Log3/SGamut3.cine than for SGamut and S-Log2. So there are many people that like to use PP8 or PP9 for internal S-Log.

However, switching the FS5’s gamma from S-log2 to S-log3 makes no difference to the raw output. And it won’t make your recorder convert the raw to ProRes/DNxHD as S-Log3 if that’s what you are hoping for. But changing the gamut does have an effect on the colors in the image.

But shouldn’t raw be just raw sensor data?

For me this is interesting, because if the camera is recording the raw sensor output, changing the Gamut shouldn’t really change what’s in the raw recording. So the fact that the image changes when you change the Gamut tells me that the camera is doing some form of processing or gain/gamma adjustment to the signal coming from the sensor. So to try and figure out what is happening and whether you should still always stick to SGamut I decided to do a little bit of testing. The testing was only done on an FS5 so the results are only applicable to the FS5. I can’t recall seeing these same changes with the FS7.

DSC Labs Chroma Tru Test Chart.

For the tests I used a DSC Labs Chroma-tru chart as this allows you to see how the colors and contrast in what you record changes both visually and with a vectorscope/waveform. As well as the chart that you shoot, you download a matching reference overlay file that you can superimpose over the clip in post to visually see any differences between the reference overlay and the way the shot has been captured and decoded. It is also possible to place another small reference chart directly in front of the monitor screen if you need to evaluate the monitor or any other aspects of your full end to end production system. It’s a very clever system and I like it because as well as being able to measure differences with scopes you can also see any differences quite clearly without any sophisticated measuring equipment.

Test workflow:

The chart was illuminated with a mix of mostly real daylight and a bit of 5600K daylight balanced light from a Stella LED lamp. I wanted a lot of real daylight to minimise any errors that could creep in from the spectrum of the LED light (The Stellas are very good but you can’t beat real daylight). The camera was set to 2000 ISO. The raw signal was passed from the camera to an Atomos Shogun Inferno where the clips were recorded as both ProRes Raw and also by using the recorders built in conversion to S-Log2 for internal recording as ProRes HQ. I did one pass of correctly exposed clips and a second pass where the clips were under exposed by 1 stop to asses noise levels. The lens was the 18-105mm kit lens, which without the cameras built in lens compensation does show a fair bit of barrel distortion as you will see!

The ProRes clips were evaluated in DaVinci Resolve using the DaVinci Color Managed workflow with the input colorspace set to S-Log2/Sgamut for every clip and output colorspace set to 709. I also had to set the input range of the ProRes clips to Full Range as this is what S-Log2 files always are. If I didn’t change the input range to Full Range the clips exhibited clipped and crushed black after conversion to 709, this confirms that the clips recorded by the Shogun were Full Range – which follows the S-Log specifications.

I did also take a look at the clips in Adobe Premiere and saw very similar results to Resolve.

I will do a separate report on my findings with the ProRes Raw in FCP as soon as I get time to check out the ProRes raw files properly.

So, what did I find?

In the images below the reference file has been overlaid on the very center of the clip. It can be a little hard to see. In a perfect system it would be impossible to see. But you can never capture the full contrast of the chart 1:1 and all cameras exhibit some color response imperfections. But the closer the center overlay is to the captured chart, the more accurate the system is. Note you can click on any of the capture examples to view a larger version.

Digi-ChromaMatch-Lt Using different gamuts when shooting raw with the PXW-FS5
This is the reference file (by the time it gets posted on my website as a jpeg I would no longer guarantee the colors etc. But when you look at the images below you will see this superimposed over the center of the clips.

Below is Picture Profile 6 (PP6) SGamut with S-Log2. It’s pretty good match. The camera didn’t quite capture the full contrast of the chart and that’s to be expected, reflections etc make it very difficult to get perfect blacks and shadow areas. But color wise it looks quite reasonable although the light blue’s are a little weak/pink.

SGamut_1.1.1 Using different gamuts when shooting raw with the PXW-FS5
SGamut and S-Log2

Below is Picture Profile 7 (PP7) SGamut3 with S-Log3. Straight away we can see that even though the camera was set to S-log3, the contrast is the same in the S-Log2 color managed workflow proving that the gamma of the recording is actually ProRes recording from the Shogun is S-log2, confirming what we already know which is that changing the log curve in the camera makes no difference to the raw recording and no difference to the raw to ProRes conversion in the recorder.

Note the extra noise in the greens. The greens appear to have more color, but they also appear a little darker. If you reduce the brightness of a color without altering the saturation the color appears to be deeper and I think that is what is happening here, it is a lightness change rather than just a saturation change. There is also more noise in the darker bars, grey and black really are quite noisy. Light blues have the same weak/pink appearance and there is a distinct green tint to the white, grey and black bars.

SGamut32_1.5.1 Using different gamuts when shooting raw with the PXW-FS5
SGamut3 with S-Log3

Below is when the camera was set to SGamut3.cine with S-Log3. Again we can see that the recording gamma is obviously S-Log2. The greens are still a touch stronger looking but now there is less noise in the greens. Cyan and reds are slightly lighter than SGamut and yellows appear a bit darker. This is also a little more noisy overall than SGamut, but not as bad as SGamut3. When you play the 3 clips, overall SGamut has the least noise, SGamut3.cine is next and then SGamut3 is clearly the noisiest. As with SGamut there is a distinct green tint to the white, grey and black bars.

SGamut3cine2_1.6.1 Using different gamuts when shooting raw with the PXW-FS5
SGamut3.cine with S-Log3

So that’s what the images look like, what do the scopes tell us. Again I will start with SGamut and we can see that the color response is pretty accurate. This suggests that Atomos do a good job of converting the raw to S-Log2/SGamut before it’s recorded and confirms what we already know which is this is that this is clearly how the system is designed to work. Note how the Red strip falls very close to the R box on the 2x vectorscope, yello almost in Y, green very close to G, Blue almost in B. Magenta isn’t so clever and this probably explains why the pinky blues at the top of the chart are not quite right. Do remember that all these test were done with the preset white balance so it’s not surprising to see some small offsets as the white balance won’t have been absolutely perfect. But that imperfection will be the same across all of my test examples.

Screenshot-2019-03-06-at-12.23.31 Using different gamuts when shooting raw with the PXW-FS5
SGamut + S-Log2

Below is SGamut3. The first thing I noticed was all the extra noise on the right side of the waveform where the greens are. The waveform also shows the difference in lightness compared to SGamut with different colors being reproduced at different brightness levels. The greens are being reproduced at a slightly lower luma level and this is probably why the greens appear more saturated. Also notice how much more fuzzy the vectorscope is, this is due to some extra chroma noise. There is a bit more red and magenta is closer to it’s target box, but all the other key colors are further from their boxes. Yellow and Green and Cyan are all a long way from their target boxes. Overall the color is much less accurate than SGamut and there is more chroma noise.

Screenshot-2019-03-06-at-12.23.53 Using different gamuts when shooting raw with the PXW-FS5

And finally below is SGamut3.cine. There is less noise on the green side of the waveform than SGamut and SGamut3 but we still have a slightly lower luma level for green, making green appear more saturated. Again overall color accuracy is not as good as SGamut. But the vector scope is still quite fuzzy due to chroma noise.

Screenshot-2019-03-06-at-12.24.24 Using different gamuts when shooting raw with the PXW-FS5

Under Exposure:

I just want to show you a couple of under exposed examples. These have had the under exposure corrected in post. Below is SGamut and as you can see it is a bit noisy when under exposed. That shouldn’t be a surprise, under expose and you will get noisy pictures.

SGamut_1.1.1-1 Using different gamuts when shooting raw with the PXW-FS5
SGamut with S-Log2 1 stop under (exposure corrected in post)

Below is SGamut3 and you can really see how much noisier this is than SGamut. I recommend clicking on the images to see a full screen version. You will see that as well as the noise in the greens there is more chroma noise in the blacks and greys. There also seems to be a stronger shift towards blue/green in the whites/greys in the under exposed SGamut3.

SGamut3_1.2.1 Using different gamuts when shooting raw with the PXW-FS5
SGamut3 with S-Log3 1 stop under (exposure corrected in post)

Conclusions:

Clearly changing the gamut makes a difference to the raw output signal. In theory this shouldn’t really happen. Raw is supposed to be the unprocessed sensor output. But these test show that there is a fair bit of processing going on in the FS5 before the raw is output. It’s already known that the white balance is baked in. This is quite easy to do as changing the white balance is largely just a matter of changing the gain on the pixels that represent red and blue relative to green. This can be done before the image is converted to a color image.

What I believe I am seeing in this test is something more complex than that. I’m seeing changes in the luminance and gain levels of different colors relative to each other. So what I suspect is happening is that the camera is making some independent adjustments to the gamma of the Red, Blue and Green pixels before the raw signal is output. This is probably a hang over from adjustments that need to be made when recording S-Log2 and S-Log3 internally rather than something being done to deliberately adjust the raw output. But I didn’t design the camera so I can’t be sure that this is really the case. Only Sony would know the truth.

Does it matter?

Yes and no. If you have been using SGamut3.cine and have been getting the results you want, then, no it doesn’t really matter. I would probably avoid SGamut3. It really is very noisy in the greens and shadows compared to the other two. I would be a little concerned by the green tint in the parts of the image that should be colour free in both SGamut3 and SGamut3.cine. That would make grading a little tougher than it should be.

So my advice remains unchanged and continues to match Sony’s recommendation. This is that you should use PP7 with SGamut and S-Log2 when outputting raw. That doesn’t mean you can’t use the other Gamuts and your milage may vary, but these tests do for me at least confirm my reasons for sticking with PP7.

Both Premiere and Resolve show the same behaviour. Next I want to take a look at what happens in FCP with the ProRes Raw clips. This could prove interesting as FCP decodes and converts the FS-Raw to S-Log3 and SGamut3.cine rather than S-Log2/Sgamut by default. Whether this will make any difference I don’t know. What I do know is that having a recorder that’s converting to S-Log2 for display and software that converts to S-Log3 is very confusing as you need different LUT’s for post and the recorder if you want to use LUT’s for your monitoring. But FCP will have to wait for another day. I have paying work to do first.

Recording the slow motion S&Q output of an FS5 to a normal external recorder (not raw).

This has been asked a couple of times. How do I record the slow motion S&Q output of my PXW-FS5 to an external recorder if I don’t have the raw option or don’t want to use raw.

Well it is possible and it’s quite easy to do. You can do it with either an SDI or HDMI recorder, both will work. The example here is for the new Atomos Ninja V recorder, but the basic idea is the same for most recorders.

Just to be absolutely clear this isn’t a magic trick to give you raw with a conventional non raw recorder. But it will allow you to take advantage of the higher quality codec (normally ProRes) in the external recorder.

Oh and by the way – The Ninja V is a great external monitor and recorder if you don’t want raw or you need something smaller than the Inferno.

So here’s how you do it:

In the camera menu and “Rec Set” – set the file format to XAVC HD and the Rec Format to 1080/50p or 1080/60p it MUST be 50p or 60p for this to work correctly.

DSC_0340 Recording the slow motion S&Q output of an FS5 to a normal external recorder (not raw).


In “Video Out” select the HDMI (for the Ninja, if you recorder has SDI then this works with SDI too).

DSC_0339 Recording the slow motion S&Q output of an FS5 to a normal external recorder (not raw).

Set the SDI/HDMI to 1080p/480i or 1080p/560i it MUST be p not i

Set HDMI TC Output to ON

Set SDI/HDMI Rec Control to ON

DSC_0338 Recording the slow motion S&Q output of an FS5 to a normal external recorder (not raw).

Connect the Ninja (or other recorder) via HDMI and on the Ninja under the input settings set the record trigger to HDMI – ON. If you are using a recorder with SDI you should have similar options for the SDI input.

DSC_0342 Recording the slow motion S&Q output of an FS5 to a normal external recorder (not raw).

So now what will happen is when you use the S&Q mode at 100fps or higher the camera will act as normally, you will still need a SD card in the camera. But when the camera copies the slow motion footage from the internal buffer to the SD card the external recorder will automatically go into record at the same time and record the output stream of the buffer. Once the buffer stream stops, the recorder will stop.

The resulting file will be 50p/60p. So if you want to use it in a 24/25/30p project and get the full slow-mo benefit you will need to tell the edit software to treat the file as a 24/25/30p file to match the other clips in your project. Typically this is done by right clicking on the clip and using the “interpret footage” function to set the frame rate to match the frame rate of your project or other footage.

And that’s it. It’s pretty simple to do and you can improve the quality of your files over the internal recordings, although I have to say you’ll be hard pushed to see any difference in most cases as the XAVC is already pretty good.

Why I Choose To Shoot ProRes Raw with the FS5

This is a much discussed topic right now, so as I promised in my last article about this, I have put together a video. Unfortunately YouTube’s compression masks many of the differences between the UHD XAVC and the ProRes Raw, but you can still see them, especially on the waveform scopes.

To really appreciate the difference you should watch the video on a large screen at at high quality, preferably 4K.

PXW-FS5 Screen Protector updated images.

Here are some updated pictures of the screen protector for the FS5 that I sell via Shapeways. It’s not an exciting product, it’s just a clip on plastic cover that protects the LCD panel from damage when you are not using the camera. I travel a lot with my camera and the unprotected LCD screen is very vulnerable and could easily get scratched or worse still smashed. Arriving for a shoot and finding the FS5’s LCD screen smashed would be a disaster!

If you want one for yourself you can order them through my Shapeways store: https://www.shapeways.com/shops/alisterchapman

AJC05188 PXW-FS5 Screen Protector updated images.
PXW-FS5 screen protector front view.

AJC05190 PXW-FS5 Screen Protector updated images.
PXW-FS5 screen protection cover clipped on to the LCD screen.

AJC05192 PXW-FS5 Screen Protector updated images.
PXW-FS5 clip on screen saver attached to the LCD.

What are the benefits of ProRes Raw with the PXW-FS5?

There has been a lot of discussion recently and few videos posted that perhaps give the impression that if you shoot with S-Log2 on an FS5 and compare it to raw shot on the FS5 there is very little difference.

Many of the points raised in the videos are correct. ProRes raw won’t give you any more dynamic range. It won’t improve the cameras low light performance. There are features such as automatic lens aberration correction applied when shooting internally which isn’t applied when shooting raw.  Plus it’s true that shooting ProRes raw requires an external recorder that makes the diminutive little FS5 much more bulky.

So why in that case shoot ProRes Raw?

Frankly, if all you are doing is producing videos that will be compressed to within an inch of their life for YouTube, S-Log2 can do an excellent job when exposed well, it can be graded and can produce a nice image.

But if you are trying to produce the highest quality images possible then well shot ProRes raw will give you more data to work with in post production with fewer compression artefacts than the internal 8 bit UHD XAVC.

I was looking at some shots that I did in preparation for my recent webinar on ProRes raw earlier today and at first glance there isn’t perhaps much difference between the UHD 8 bit XAVC S-Log2 files and the ProRes raw files that were shot within seconds of each other. But look more closely and there are some important differences, especially if skin tones are important too you.

Skin tones sit half way between middle grey and white and typically span around 2 to 3 stops. So with S-Log 2 and an 8 bit recording a face would span around 24 to 34 IRE and have a somewhere between 24 and 35 code values – Yes, that’s right, maybe as few as 24 shades in each of the R, G and B channels. If you apply a basic LUT to this and then view it on a typical 8 bit monitor it will probably look OK.

But compare that to 12 bit linear raw recording and the same face with 2 to 3 stops across it will have anywhere up to 10 to 20 times as many code values ( somewhere around 250 – 500 code values depending on exactly how it’s exposed) . Apply the same LUT as for the S-Log2 and on the surface it looks pretty much the same – or does it?

Look closely and you will see more texture in the 12 bit raw. If you are lucky enough to have a 10 bit monitor the differences are even more apparent. Sure, it isn’t an in-your-face night and day difference but the 12 bit skin tones look less like plastic and much more real, they just look nicer, especially if it’s someone with a good complexion.

In addition looking at my test material I am also seeing some mpeg compression artefacts on the skin tones in the 8 bit XAVC that has a smoothing effect on the skin tones, reducing some of the subtle textures and adding to the slightly un-real, video look.

The other deal with a lack of code values and H624 compression  is banding. Take 8 bit S-Log2 and start boosting the contrast in a sky scene, perhaps to bring out some cloud details and you will start to see banding and stair stepping if you are not very careful. You will also see it across wall and other textureless surfaces. You can even see this on your grading suite waveform scopes in many cases. You won’t get this with well exposed 12 bit linear raw (for any normal grading at least).

None of these are huge deals perhaps. But what is it that makes a great picture? Take Sony’s Venice or the Arri Alexa as examples. We know these to be great cameras that produce excellent images. But what is it that makes the images so good? The short answer is that it is a combination of a wide range of factors, each done as well as is possible. Good DR, good colour, good skin tones etc. So what you want to record is whatever the sensor in your camera can deliver as well as you can. 8 bit UHD compressed to only 100Mb/s is not really that great. 12 bit raw will give you more textures in the mid range and highlights. It does have some limitations in the shadows, but that is easily overcome with a nice bright exposure and printing down in post.

And it’s not just about image quality.

Don’t forget that ProRes Raw makes shooting at 4K DCI possible. If you hope to ever release your work for cinema display, perhaps on the festival circuit, you are going to be much better off shooting in the cinema DCI 4K standard rather than the UHD TV standard. It also allows you to shoot 60fps in 4K (I’m in the middle of a very big 4K 60p project right now). Want to shoot even faster – well with ProRes Raw you can, you can shoot at up to 120fps in 4K. So there are many other benefits to the raw option on the FS5 and recording to ProRes raw on a Shogun Inferno.

There is also the acceptability of 8 bit UHD. No broadcaster that I know of will ever consider 8 bit UHD unless there is absolutely no other way to get the material. You are far more likely to be able to get them to accept 12 bit raw.

Future proofing is another consideration. I am sure that ProRes raw decoders will improve and support in other applications will eventually come. By going back to your raw sensor data with better software you may be able to gain better image quality from your footage in the future. With Log you are already somewhat limited as the bulk of the image processing has already been done and is baked into the footage.

It’s late on Friday afternoon here in the UK and I’ve promised to spend some time with the family this evening. So no videos today. But next week I’ll post some of the examples I’ve been looking at so that you can see where ProRes raw elevates the image quality possible from the FS5.

Using an FS5 to shoot in low light – what can I do?

The PXW-FS5 is a pretty good camera overall. Compared to cameras from 6 or 7 years ago it’s actually pretty sensitive. The exposure rating of 800 ISO for the standard rec-709 picture profile tells us that it is a little more than twice as sensitive as most old school shoulder cams. But it also suggests that it is only around half as sensitive as the king of low light, the Sony A7S. The A7S is so sensitive because it’s sensor is 1.5x bigger than the sensor in the FS5 and as a result the pixels in the A7S are almost twice the size, so are able to capture more light.

So what can you do if shooting in low light? 

The most important thing to do is to make the optical system as efficient as possible. You want to capture as much of the available light as you can and squeeze it down onto the FS5’s sensor. If you take a fast full frame lens and use it in conjunction with a Speed Booster type adapter you will end up with similar performance to using the same lens, without the speed booster on an A7S.

This is because the lens has a fixed light gathering capability. Use it on an A7S and all of the captured light is passed to all of those big pixels on the sensor. The light is split evenly across 4K’s worth of pixels.

Use it on an FS5 with a speedbooster and the same thing happens, all of the light is compressed down, which makes it brighter and all of this now brighter light falls on 4K’s worth of pixels. The smaller pixels are about half as sensitive, but now the light is twice as bright, so the end result is similar.

metabones_mb_spom_m43_bm3_speed_booster_ultra_0_71x_1259766-1024x1024 Using an FS5 to shoot in low light - what can I do?
A speedbooster adapter such as the Metabones makes a huge difference in low light. But you MUST use a full frame lens.

The biggest performance gains are to be had from using a very fast lens and then making sure all the light from the lens is used, none wasted. Anything slower than f2.8 will be a waste. If you are thinking of using the Sony f4 lens for very low light… well frankly you may as well not bother. The lens is THE most important factor in low light. When I go up to Norway to shoot the Aurora I use f1.4 and f1.8 lenses.

What about Picture Profiles?

The standard picture profile isn’t a bad choice for low light but you might want to look at using cinegamma 3. Although with a low light, low contrast scene none of the picture profiles will be significantly different from the others with the exception of PP2, PP7, PP8 or PP9. None of the profiles make the camera more sensitive, the sensitivity is governed by the sensor itself and all the profiles do is alter the way gain is distributed across the image.

PP2 will crush your shadows giving less to work with in post. The log curves in PP7,8,9 will roll off the darkest parts of the image, again giving you less in post. So I would probably avoid these.

For color I suggest using the Pro colour matrix. This works well for most situations and it will help limit the noise levels as it keeps the saturation fairly low keeping the noisy blue channel in check.

Gain or ISO?

I recommend you set the camera to gain rather than ISO as the ISO’s for each each gamma curve are different, so it can be difficult to understand how much gain is being added, especially if you are switching between gamma curves. Use gain and you will have a good idea of the noise levels as every time you add +6dB the image becomes one stop brighter and you double the noise in the image, +12 dB is 2 stops brighter and 4x noisier than 0dB etc. ISO is an exposure rating, it is not a sensitivity measurement. But don’t use too much gain or too high an ISO as this will affect you ability to use some of the very good post production noise reduction tools that are available.

Noise and Noise Reduction.

If shooting in very low light then you are quite probably going to want to use some noise reduction tools in post production. “Neat Video” works very well at cleaning up a noisy image as do the various NR tools in the paid versions of DaVinci Resolve.  These post production  tools work best when the noise is clean. By that I mean well defined. When using any of the 709 or Cinegamma curves a bit of gain can be used, but I wouldn’t go above 12dB as above this the NR starts to introduce a lot of smear and this than makes it hard for any post production NR processes like Neat Video to do a decent job without the image turning into a blurry mess. So don’t go crazy with the gain or use very high ISO’s as the post production NR won’t work as well on footage that already has a lot of in camera NR applied.

And if you can add a little light-

If you are adding any light use a daylight balanced light where you can. Video cameras are least sensitive in the blue channel. If you use a tungsten light which is predominantly warm/red to get a good white balance you have to increase the gain of the cameras least sensitive and as a result most noisy blue channel. This will add more noise than if you use a daylight balance light as for daylight you need less gain in the noisy blue channel.

There is no miracle cure for shooting in very low light levels. But with the right lens and a speedbooster the FS5 can do a very good job. But just in case yo haven’t worked it out already, I’ll say it one more time: The lens is the most important bit! Beyond this your next step would be adding an image intensifier for that green night vision look.