For a Low Light shoot with FX6 / FX9 - best ISO and Color profile settings?

Joshua Milligan said:
Hey man, why do you think you'll need Neat Video before you even go on the shoot? With the FX6, you shouldn't be needing any sort of denoiser. In fact, I personally haven't used a denoiser in many years and I shoot a lot of doc stuff, including wildlife doc projects. A proper exposure should yield good enough footage to not need anything like that in post outside of an emergency.

Also, why do you plan to stabilize many shots in post? I've seen this a lot since the FX9/FX6 came out. So many people are relying on post stabilization in Catalyst Browse to get smooth footage. That's a long, time consuming process, especially if you plan to use it a lot. For me, I only use the gyro sensor data stabilization in CB when I somehow accidentally made a shot shaky (it happens), or if I wanted to make like one shot on a commercial project a little smoother than I was able to get it on the shoot. But I'm certainly not going into a project thinking that's going to be my workflow. That sounds like a nightmare!
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My thoughts, exactly.
 
Joshua Milligan said:
Hey Doug, why is Custom mode different from Cine EI on the FX6 outside of workflow? I'm not trying to argue with you, I am just asking so I understand.
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I didn't want to waste space quoting your whole post, but I think you bring up some excellent points. You might be right and maybe I'm wrong to assume that the visual results will be different when you shoot LOG with CINE EI vs. Custom. To be honest, I haven't tested it on the FX6 and my assumptions are based on experience with other cameras. I could be wrong. However, it really doesn't make any difference to me personally one way or the the other, so maybe you should setup some very controlled A/B tests and let us know what you find out. Ultimately that is the only way to figure something like this out. I'd be interested to see the results, but not interested enough to do them myself. :-)

BTW, there's no need to say you're not trying to argue. I never feel that is the case with your posts. We all need to be questioned and challenged on our posts to keep us on our toes. I appreciate a good debate.
 
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Doug Jensen said:
I'm just saying that I expose High and Low to the exact same target level and I see no advantage to going beyond that target level for High -- thus over-exposing. If there is an advantage to the technique you mention in post #12, I'd like to see some video that shows it, and also some explanation as to why that technique would work for High but not for Low.

I think threads like this really make exposure seem a heck of a lot more complicated than it needs to be. Just choose a target level . . . and if you can't hit your target with Low then switch to High, but the target stays the same. Simple as that.
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I'm not going to go to the effort of making a side-by-side video. But the improvement in the noise floor when you overexpose the 12,800 High Base by one or two stops, is significant, and makes cutting 12,800 EI material in with 800 EI material, seamless.

This is immediately apparent when you compare the footage side-by-side in the grade.

Overexposing the 800 EI "low base" mode is completely unnecessary (because the camera is so clean at that level).

Does that mean the normally exposed 12,800 EI material is unusable? No. But it's touch-and-go to cut that material in with 800 EI seamlessly (even with fine-tuned temporal noise reduction). The jump is the noise floor between the two modes is readily apparent.
 
Doug Jensen said:
You see, that is the problem with this conversation about exposure, there are literally thousands of different "what if" scenarios that anyone can throw out there. Never ending. I'll answer one and you will bring up another "what if". That is why I tried to limit the conversation to a standard 60 Minutes style interview, which is easy to deal with. I cannot spend time explaining my process/methods for every contigency.
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Quite. It sounds like you agree that exposure is a complicated affair because of the variety of scenarios you may encounter and the different goals you may have for different scenes. And therefore different strategies are required at different times

I always agreed that in a controlled-light or uniform light scenario, there will be an accurate exposure and everything else is technically inaccurate. (Whether or not you desire accuracy is a different question.)

As to techniques for noise suppression, it sounds like you don't think noise is a problem for a proper exposure at either 800 ISO on the fs7 or 12800 on the fx6. But we may have to agree to disagree there, and I don't think I'm alone

PS in case it was unclear, I enjoy these technical debates, don't mean to waste anyone's time, and don't take anything you say personally
 
ahalpert said:
PS in case it was unclear, I enjoy these technical debates, don't mean to waste anyone's time, and don't take anything you say personally
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Same here. I speak bluntly sometimes but I don't mean anything personal by it.

BTW, on the FS7 I've always exposed S-LOG2/3 with white at 75 IRE, so you may consider that ETTR. I don't consider it ETTR because Sony's suggestion of 60 is totally bogus and I don't know anyone who actually exposes S-LOG anywhere near that level. There is no room for error at 60 and there's also no need to allow 49 IRE of headroom. On the FX6, I started at 68 but have gradually moved up to 72. I also don't consider that ETTR. That is just hitting my target.
 
Grug said:
I'm not going to go to the effort of making a side-by-side video. But the improvement in the noise floor when you overexpose the 12,800 High Base by one or two stops, is significant, and makes cutting 12,800 EI material in with 800 EI material, seamless. This is immediately apparent when you compare the footage side-by-side in the grade.
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So, that begs the question, at what level would you expose white if you are overexposing by two stops? I'm aiming for 72 IRE as my "normal" exposure, which you might consider overexposure. We might not be so far off from each other.
 
Doug Jensen said:
So, that begs the question, at what level would you expose white if you are overexposing by two stops? I'm aiming for 72 IRE as my "normal" exposure, which you might consider overexposure. We might not be so far off from each other.
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I think this probably has a lot to do with difference of opinion in this thread concerning exposure. I could definitely see how what one person considers ETTR, or overexposed, could be considered properly exposed to someone else.
 
But one concrete difference is that Grug says he sets a different target for 12800 vs 800 while Doug says he sets the same target
 
ahalpert said:
But one concrete difference is that Grug says he sets a different target for 12800 vs 800 while Doug says he sets the same target
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Yes, that is correct. Same target for either one.
If I was to push HIGH base even farther, that would put it up in the high 70's or 80's and there's no way that is going to provide better results in post. S-LOG is a curve so going too high is a mistake.
 
Doug Jensen said:
On the FX6, I started at 68 but have gradually moved up to 72. I also don't consider that ETTR. That is just hitting my target.
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I don't really ETTR in the sense of exposing as hot as possible without blowing out. I think that the tonality/gradient/color really suffers if you push your values too high and then bring them down. And I don't care that much about a little noise anyway. But on the a7siii I definitely expose differently for high base for the sake of getting better, cleaner shadows
 
BTW, i have actually done my own testing in 5 IRE increments from 60 to 95 IRE. Graded and analyzed in Resolve on my scopes and OLED monitors.
 
ahalpert said:
I don't really ETTR in the sense of exposing as hot as possible without blowing out. I think that the tonality/gradient/color really suffers if you push your values too high and then bring them down.
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I know this thread is about S-LOG, but you have summarized my complaints about S-Cinetone. In the broadcast world, bright whites should typically hit around 90 IRE, but the tonality/gradient/color really suffers at that level and is difficult to correct in post.
 
I've posted this before, but if anyone is curious to see LO vs HI at exposure intervals you can check this out (marks 2:15 and 4:29 for the Lo/Hi footage):

I was going off Sony's recommended exposure levels (61 or so IRE for white) for "base" exposure, which I think most of us would agree is too low (certainly for HI base ISO).

To my eyes, if you're exposing a stop or so brighter than the "recommended" levels the footage should cut together seamlessly. And it's probably fair to say that rating the camera at 6400 in HI base—or exposing white at 70ish—is more appropriate for "correct" exposure in normal situations (i.e., interviews).

Having said all this, the fact that we can have discussions about clean exposures at 12,800 ISO is pretty fantastic :smile:
 
Doug Jensen said:
Perhaps your workflow in post is where we differ. Are you doing proper grading in Resolve or just dumping a LUT on it in your NLE?
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I'll just add that - if you do use Doug's methods for exposure - and are shooting broadcast interview or b-roll - then "dumping a LUT" should really be the only thing you need to do (so long as you've created that LUT with the offset for your exposure method - which can / should be done in resolve.)
I like to grade creatively - and mix it up occasionally - but if you follow very stringent methods for exposing and your lighting ratios and keep to them on set - I find that a well created LUT can be used on many a project without having to do any extensive "grading".
 
Shoot is complete. It was wild. We ended up shooting 100% HIGH BASE, up a stop (so EI at half). There was simply not enough light for low base. At first glance, it looks great with the Sony 709 LUT applied!!

But, my sad story is that I screwed up my cam's white balance. This is only my second shoot with this cam and I pressed the wrong button at one point. I meant to press the push auto button to temporarily bring in autofocus and instead I pushed the button below it for Auto White Balance. And then in my panic I didn't hit "cancel." 20 seconds later, not knowing anyway to get back to what I had -- it would have been nice to have an UNDO button -- I basically just dialed in the white balance to about the same temperature number.
But it doesn't look the same, folks. I must say, the footage before the white balance eff-up looks GORGEOUS! So my first task is to try to color correct to get back to how it looked before the mishap. I'm going to move this discussion about my white balance screw-up to my other thread that deals with matching cameras.

Thanks for everyone's input.
 
Glad the shoot went well apart from the WB problem. I did that myself on the first shoot I did with the FX6. It was a simple head and shoulders interview with minimal lighting but I pushed the same button you did and gave myself some tricky post work. And I agree with you about the FX6 colours. My previous two cameras were Canons and I find the FX6 to be more accurate to what you’re shooting
 
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Also, if you're using LUTs you could try the Arri one. It gives similar results but with slightly less contrast, which might help with a low light shoot. I don't see any increase in noise with the Arri compared with the Sony.
 
Doug Jensen said:
So, that begs the question, at what level would you expose white if you are overexposing by two stops? I'm aiming for 72 IRE as my "normal" exposure, which you might consider overexposure. We might not be so far off from each other.
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I've been monitoring with a LUT applied on output, so the waveform only tells me the LUTted IRE levels (so with the camera set to 3200 EI, 6400 EI or 12800 EI - nothing changes waveform wise, the values are measured based on the EI value, not the underlying base ISO mode). Plus I'm still a light meter guy, so for the most part I just set that to the relavant ISO and meter accordingly.

The only real issue I've had with this method, is metadata passthrough. Having shot with the FX6 mostly recording to Prores Raw, there hasn't been reliable metadata passthrough, marking the high-base clips clearly as 3200 EI or 6400 EI.

Potentially this may have been fixed with the most recent firmware (for both the FX 6 and the Atomos Ninja V) but I haven't tested that yet.

To-date though, it's certainly been one of the reasons I've despised the current Prores Raw workflow with the camera.
 
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