Question about Powergrades

This is an amazingly informative response. A lot to wrap my head around though, I'm truly a child in this world of film and colour.

I'm curious about using the Kodak Portra 800 film sim as a method of similifying the workflow. I'm using a A6400, does that mean just keep it in Slog2, and not bother with adjusting saturation to 15+?

Does using this method mean we just convert striaght to Rec 709 using the conversation LUT, and then we don't need to do any colour correction, and can start tweaking the 16mm Powergrade right away?

BTW, I'm deeply in love with the Kodak Portra 800 film sim. I just keep coming back to it.

Thanks again,

Matthew

Hei there!

Thanks for the question.

You would use Log as you normally would.

I generally like to overexpose by 1-2 stops, depending on the condition, generally trying to save as much of the highlights as possible. With digital it's easier to recover detail from the shadows.

Same with Film Simulations, You can Underexpose by half a stop, some times even one stop and later recover the shadow details in post, but if you overexposed, the information is gone.

My power Grades were made to work for both Rec709 and Log Footage, so they are super versatile in case you want to use them on non log Film Simulations or standard Log footage.

Obviously contrast & color matching will be needed if you want consistency between them if you might be using 2 totally different picture profiles.

As for Log Conversion, I've included a node where you choose your Official Camera Brand Log to Rec709 LUT (Sony, Canon, Fuji, Panasonic etc) as a basic correction, which can be enabled or disabled depending on your needs.

This makes it easier to match log footage with non log footage.

So all you have to do, is apply the power grade onto the footage, open the Compound Node, enable the Log Conversion Node and adjust Hue to your liking.

Sometimes Log footage might come a little bit magenta and green in the skintones even after conversion, so in the Log conversion Node I like to shift the Hue values towards the right, from 50 to around 52.

That will correct colors and from there you can start tweaking Contrast & Color on your liking.

Temporarily increasing the saturation helps notice colors and helps you decide if the colors are right where you want them to be or not.

With Exposure I try to keep things in Balance, preserving as much detail in the shadows and highlights or expose in such way it puts focus on the subject.

On digital it's always easier to recover information from the shadows than from highlights, which is the exact opposite than with Analog Film.

Idea is if you want to match your rec709 to your log footage, it's not going to be easy, but there are couple trick that help.

On digital, once the highlights are clipped, there is basically no information to recover, and since Log Footage has a super soft high dynamic range, maybe try to underexpose with rec709 and later on, you can recover some details from the shadow area.

If you are not trying to match rec709 with Log footage, then with regular film simulations I would expose normally, for the subject, because they are more contrasty than log, have less dynamic range and most probably I will loose some detail in either extremities, shadows or highlight.

I usually like to underexpose by half a stop, but there are some film simulation like Ektachrome Kodachrome and more which look better 1 stop overexposed. You need to rely on your eyes to expose properly, look at the image and decide which side looks more pleasing, underexposed, correctly exposed, or overexposed.

if you want to speed up the process and skip the color correction part of the SLog3, then I recommend using and alternation of Kodak Portra 800 Film Simulation, film recipe which is based on S-Log2, it will give you better colors and noticeably less noise in the shadows.

you can change the gamma from Slog2 to Slog3 Saturation at +15 and the rest of the settings the same.

You will need to use the Color Space Transform to convert the Cinema Color Mode (P3 Color Space) to Rec709 for accurate color reproduction on screens, just like I showcase in the following GIF

These power Grades are also finely refined to work with 8bit footage, so you will have less chances of color falling apart compared to power grades which are only calibrated for 10bit or higher color depth footage.

Just as a heads up, I know you said you are shooting 10bit on the a7IV but if you ever plan shooting 8bit, slog3 might be unusable, or just too much hassle to try to clean up the image. I don't ever bother to shoot slog3 in 8bit, It's almost impossible to get clean results and it can end in frustration. With 8 Bit stick with Slog2

Hope this helps, let me know if you have any other questions :D