A7s post workflow

squig

squig

Veteran
I've been doing some tests with 5D raw files debayered/converted to prores4444 in AE and graded in both FCPX and R11 with the same filmconvert & Impulz Luts applied. FCPX crushes the image into a REC709 colour space. Resolve doesn't crush the image, the DaVinci colour space has a wider gamut & maintains the filmic gauze over the image (that Kholi likes to get rid of). Given that the A7s has a high dynamic range and S-Log applies a nice filmic gauze, FCPX is probably not going to be the best post route.
 
FCPX works but you have to lower the exposure via the highlight and lift the shadows via colorboard first. I find that highlight -12% and shadow plus 2-4% works. Adjust mids and sat if you aren't using anything else. Any colorboard adjustment seems to be seen as priority in FCPX, so making this correction first does have an affect on the image before you stack everything else on top of it. Probably obvious but worth reminding, just like adding LUT's in the early nodes in Resolve is destructive rather than adding at the end.
 
Last edited:
Okay kids after much trial and error I think I've discovered the secret sauce (for now). Up until now just about everything I tried in post looked very average. The problem has been finding the best way to de-SLOG. I finally bit the bullet and did a web search yesterday (duh) and came across macgregors S-log - cineon input LUT http://www.hingsberg.com/index.php/2014/05/sony-f3-resurrected-luts/

My workflow goes as follows-
A7s S-LOG cinema profile +2 EV
-4 detail, 0 saturation
R11 SLOG - cineon input LUT
Filmconvert Ari Alexa LOG C
KDP400 ptra stock
roughly -0.150 to -0.250 exposure
grain to taste (I went with 50% full frame on these shots)
contrast around 900
around -12 mid tone red (I was shooting at magic hour with Leica glass so this will vary)

This is the result (drag and drop to see full 1080p screenshot)
UOCwizX.png


fRLAdmt.png
 
Last edited:
The skin isn't perfect, a bit green (that stock is a bit green, she has very pale Eurasian skin and I took too much red out). I don't claim to be a colourist but so far this workflow is giving me the best results and I think it's a good base to start with. Shooting at magic hour and guesstimating white balance isn't the best scenario for judging skin tones. I'm going to do some more tests with studio lighting to determine whether I need to adjust colours in-camera.
 
Last edited:
Note to self: Don't stay up all night trying to grade in a dark room without looking at reference material :cheesy:

I've added some steps to the process-
R11 SLOG - cineon input LUT
cineon - visionspace_impulz LUT
lift gamma gain & contrast adjustments
contrast around 900
LOG generic LUT
Filmconvert default
FJ Prov 100 stock
grain to taste (I went with 50% full frame on these shots)

dIXrWt7.png


YwBenwy.png
 
Last edited:
dcarstens said:
Click to expand...

That's one of the first things I tried. There's an S-log comparison on vimeo between the A7s, F55, FS700, and F3, the A7s image doesn't match any of them. The new workflow I'm using hardly needs any adjustments, mostly just corrections for skin and it seems I can crush the blacks more without the image falling apart and end up with a much more filmic image.
 
Be warned Resolve auto selects video levels with XAVC-S files.

Another shot using the same recipe.
icm4EBG.png
 
Just about everything I've shot looks good with this workflow as long as exposure and white balance are good. The white balance was off on that first shot plus it was dark. Feed the sensor enough light and it's raw stills good.

ONlGx2u.png
 
That one is way too green for my taste, like many of your other examples. Are you sure it's not a monitor calibration thing? Does it look similar in your phone or tablet?
In general, skin should have a hue of between 20 and 29. It can go a bit away from that range if the person is actually yellowish (me) or reddish (me after 20 minutes in the sun without sunblock), but this seems too much!!
 
Samuel H said:
That one is way too green for my taste, like many of your other examples...
Click to expand...

I think it depends what kind of mood you are looking for. A lot of good movies don´t have right skin tones. I like what I see. But Ok, this one here comes closer to the correct skin tone line on the vectorscope...

 
Uwe Lansing said:
I think it depends what kind of mood you are looking for. A lot of good movies don´t have right skin tones. I like what I see. But Ok, this one here comes closer to the correct skin tone line on the vectorscope...
Click to expand...

Most features would fail the dxvuser test. Green skin, blown highlights, noise, and that wretched flare!
 
squig said:
Most features would fail the dxvuser test. Green skin, blown highlights, noise, and that wretched flare!
Click to expand...

Of course you're right about that, but I have to echo what Samuel said - I've actually been really alarmed by basically every single still you've posted; the color looks insanely off. I am not seeing it in a lot of other examples though, so I'm less alarmed that it's a camera issue. Anyway, I realize you're making choices to taste and everybody's monitor is different (and mine is FAR from calibrated) so I'm not criticizing your shots, but just to say that they really look very green to me - past what I would assume was a style choice.
 
What's alarming is people judging colour on uncalibrated screens.

Uwe that skin looks really good, I'll probably go with something in-between in the final grade, mine is way too contrasty.
 
You must log in or register to reply here.
Back
Top