Slog for greenscreen or not?

E

editatjoes

Active member
Doing some of my own testing but would like to get some second/third opinions. I have Slog and a Pix 240 so will be recording at 4:2:2 ProResHQ. Lighting will be controlled so I don't have to worry too much about exposure issues. Want to minimize noise of course, not that I'm concerned about that with the F3, but if anyone can comment based on experience I'd appreciate it. Thanks in advance.
 
Well I think definiately install the firmware update v1.2 that can reduce the ISO to 800 so less noisy. I did a shoot with it where I was the b cam - they said they had issues pulling a clean key.

Also DNXHD on the pix 240 has been having macroblocking issues in the shadows so be careful if you use the DNXHD setting.
 
how would s-log improve keying?

and regarding iso, wouldn't that have to be a hell of a lot of noise to affect the ability to key properly?

at 10bit 4.2.2, i would think the rest is lighting, no?
 
That's my thinking - this is not a situation where Slog helps. I just wanted to confirm that. I will not be shooting DNXHD.
 
eddavid said:
Well I think definiately install the firmware update v1.2 that can reduce the ISO to 800 so less noisy. I did a shoot with it where I was the b cam - they said they had issues pulling a clean key.
Click to expand...

I find that hard to believe. I can pull a super clean using my AF-100 with Nano flash. If they had issues pulling a clean key, the iso would have to be real high, the exposure/lighting off or they dont know how to pull a proper key. Or maybe the focus was too shallow? this could make pulling a key much more difficult, These cameras are so clean and with high bit-rates I find it odd anyone would have an issue pulling a clean key unless there are some other factors involved
 
IT WILL help.

The higher color accuracy will help immensely.

If anyone is having trouble pulling a key out of sLog footage, either the footage is terrible or they have no idea what they are doing. Lighting a green screen properly will make for a great key on DV, HD, 4k or 8k. The quality of the lighting is the determining factor.
 
I wasn't the DP on that shoot (that shot s log on greenscreen) and I pulled the key fine on set when i did that. there was bleeding onto the subjects - but now that I think about it - that's not a camera thing - that's bleed - that's there. not the fault of poor s log. I actually recommended they shoot it on s log because to me s log you can get more pleasing skin tones than the built-in matrix with the sony f3. also there was IR contamination on the shoot - not s log's fault again, but the camera and not using the IR filter.
 
my understanding of s-log was that it functioned primarily as an extender of dynamic range. can you explain how it makes color more accurate?
 
oh. well i had some questions before, but now i'm really​ convinced.

are you saying you don't understand how, or that you don't have an explanation?
 
im not an electrical video engineer. Slog uses better image processing algorithms, and gives more accurate colors. I dont know the details of the lines of code in the chip. the difference is clear whenyou view footage.
 
cool.

how is it clear? based on the washed out, unprocessed s-log footage, or after it's been processed? what's different? how would you quantify it? or is it more of a general impression?

just trying to understand what you're saying....
 
both before and after you de-log it, its far truer than any of the cine-gammas would be. Colorists love it. There is far less they have to do to make the image hit a neutral point color wise. The increase in dynamic range, isnt just a smoother contrast and lattitude, it extends to color information as well, as if the color signal has more "dynamic range".
 
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