Two Tests: Autofocus and Color

An important feature for run and gun is good autofocus. No, the FS700R does not have PDAF. But it does have AF and touch screen focus. So, I tested these features in low light (not a tracking test, yet).

Another FS700R issue that has been mentioned is color. Particularly when shooting Slog, necessary when shooting RAW to get the full DR. The challenge is that Slog is accompanied by a color gamut (SGamut) that is larger than REC709. But almost all screens can only show limited REC709 colors. A translation is needed between the extended color gamut of Slog and REC709 color. SGamut is proprietary (only Sony knows what it is); it is next to impossible to use color controls in an editor to make the translation. So, one uses a look-up-table (LUT) that translates SGamut to REC709 color. There is no other way. You can then deviate from the REC709 color, but it is a reasonable starting point. A lot of the poor coloring one sees is due to using the wrong LUT or none at all.

Sony supplies a LUT. Convergent Design supplies a LUT. Both for Slog2 color and gamma translation. In this video I try both LUTs and compare. I use my standard color test objects. I also test AF and push focus. Each clip starts with the CD LUT followed by the Sony LUT. There is an obvious difference.

The Sony LUT provides accurate color - the clips look exactly like what I saw. The lighting was dim and incandescent. I set the camera WB to 3200. F4, ISO2000, 0 gain, shutter 125. 60P. No adjustment in post at all except the application of the LUT.

AF does not bounce or waver; focus pulls are nice.

Well, they're not cooked chickens!

To be clear, the recording here is not raw. It's ProRes, in the S-Log2/S-Gamut color space. Only the connection between the camera and the recorder is raw.

SGamut is proprietary (only Sony knows what it is)

S-Gamut is no secret. Sony publishes the specification: https://pro.sony.com/bbsccms/assets/files/micro/dmpc/training/TechnicalSummary_for_S-Gamut3Cine_S-Gamut3_S-Log3_V1_01.pdf Logarist supports S-Gamut, based on Sony's specification. I would encourage you to try Logarist on your recordings. People have told me it works better than the Sony LUT.

The chicken video looks nice. I'd be interested in seeing some shots of people, to see how the colors are. I was never impressed with the color of the FS700R's internal recordings, but raw makes things different.

From what I understand, it is possible to record a true 60P RAW DNG with the Inferno if you do it at 2k. And the FS700 is capable of outputing 2K RAW. Could you try to do a test like this? I would love to see the results!

120 4K Slow Mo Video

How are the skin tones here, balazer? :)

I was just about to post it here.

The process was certainly much more straightforward than just using a (Sony) LUT and playing with exposure, contrast and curves. And the colors seemed good immediately, especially the greens. All I did was adjust exposure and contrast (Vegas Pro 15). I am not sure about the Logarist reds.

With both approaches, I am pretty pleased with the colors. I had not liked especially the colors from the A7s ii or the RX100 IV. The latest A6500 colors, however, are good, and the FS700R RAW Slog2 colors are too.

I am thinking to take the same clips and compare the normal Sony LUT approach with the Logarist one in a video. I will do that early next week - it's pretty easy to do.

Of course, I am not even using RAWDNG - maybe the colors are even better.

That's interesting, @markr041. Thanks for sharing.

I could probably find a way to measure and compensate for the camera's gamut, if you want to try. I've done it for other cameras.

Ok, let's PM on that.

Logarist does have an input transform for S-Log2 with BT.709 gamut. It's "Sony S-Log2 to Logarist.cube". You can try it, but I'm pretty sure that's not what the FS700R's output is. When you process 709-gamut images with a LUT meant for S-Gamut, the output looks wildly oversaturated.

When sending a raw signal from the FS700R to the Shogun, if you customize the picture profile with a different gamma setting or color mode, is that reflected in the Shogun's image? E.g., do Cine1, ITU709, and ITU709 (800%) gamma do anything? With gamma set to Cine1, do the color modes Standard, Still, Pro, and ITU709 Matrix do anything? Logarist supports BT.709 and Cine1 (if the gamuts are right), and I can easily build a transform for ITU709 (800%). Cine1 actually has almost 1 stop more highlight range on this camera than S-Log2, since it's available at a lower ISO setting.

I'm trying to wrap my head around how the Atomos raw to video recording actually works. I am thinking that the FS700R's raw output is not completely raw.

In Logarist you don't need different LUTs for -1 and -2 stops. Just drag the offset slider. (In Vegas that's Brightness in the Brightness & Contrast effect) -0.069 is -1 stop and -0.138 is -2 stops.

Wanted to shoot preparing a bubbly soda in 4K 120p slowed down and up close. Unfortunately, the soda was flat, and so is this video.

End trigger worked well, though - nailing the exact action. And skin tone and detail are excellent.

Sony LUT used to convert from Slog2.