FS7: FS7 Exposure Confusion

M

mrchirster

Well-known member
My current settings are :

CineEI rated at 1000 ISO, LC709A MLUT on monitor
My question is:
The LUT displays the image darker than it is actually recorded, how do you judge your exposure correctly?

Now with firmware 3 we can can have waveform display.. will this display the raw slog waveform or the lut waveform? What about the zebras?
I have my zebra set to 92% and try to expose usually as hot as possible to keep my shadows relatively noise free. Since I'm exposing with a LUT that has it's white level at 72% (LC709A, according to Chapman) I should probably set my zebras to 72 instead of 92, correct? I wonder if it makes more sense to switch to the REC709 (800) LUT and keep my settings at 92%.
Since I jusge my exposure through the LUT when things start blowing out above 92% I should still have some info preserved in the raw right?
 
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What ever MLUT you are using on the VF determines what level you should set your zebras not the underlying SLog3. According to LUTCalc (get it if you don't have it) LC709A 90% white should be 71.

If I'm recording SLog3 (not baking a LUT) I prefer the REC709 800% LUT on the VF and the zebras are set at 90 and 70 for skin. It looks right on the VF and the zebra levels are where you expect them to be if you've grown up shooting video.

Now that the waveform is available in the above shooting mode it's virtually impossible to screw up exposure on the FS7.
 
Thanks guys, this helps a lot. I bought LUTCalc yesterday and love the possibility to creat False Color LUTs.
I'll probably stick with rec709 800% LUT and have my zebras at 90. What if you want to expose the brightest possible before blowing out the highlights in your underlying SLOG signal? Let's say in a drk street alley with a very bright sky. Would you use the High/Low Key feature? I saw that even in this mode you get Zebras displayed.
 
mrchirster said:
Thanks guys, this helps a lot. I bought LUTCalc yesterday and love the possibility to creat False Color LUTs.
I'll probably stick with rec709 800% LUT and have my zebras at 90. What if you want to expose the brightest possible before blowing out the highlights in your underlying SLOG signal? Let's say in a drk street alley with a very bright sky. Would you use the High/Low Key feature? I saw that even in this mode you get Zebras displayed.
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Definitely use the high/low key for eyeballing clipping, it's easy to see, but don't rely upon zebras in this mode, who knows what they're measuring.
 
Setting an accurate and repeatable exposure on the FS7 in all shooting modes, including HFR, is ridiculously simple if you don't rely on mLUTs, particularly contrasty ones, and the silly Hi-Lo feature.
 
liam, i disagree. I was exposung without LUTs for the last half year or so but my footage turned out inconsistent, mostly because in doc style run and gun situations, I would judge the exposure to be right, while it was actually quite underexposed. SLOG3 is tricky to expose without a proper LUT imho
 
Nirv said:
How do you correlate the zebras in high key to normal shooting?
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I don't. But if I did, it would only take a few minutes to determine how zebras are affected by the High/Low key. It's a couple of easy numbers to come up with but it would depend on your choice of LUT because they would each be different. It would also depend on your CINE EI setting. But since I don't use LUTs in the VF, and I would certainly never use High/Low Key if I did, I can't tell you what your numbers are. But it would be simple enough to find out -- just the same way it is really easy to figure out how zebras are affected by LUTs even without High/Low key.
 
Liam Hall said:
Setting an accurate and repeatable exposure on the FS7 in all shooting modes, including HFR, is ridiculously simple if you don't rely on mLUTs, particularly contrasty ones, and the silly Hi-Lo feature.
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You took the words right out of my mouth. And I love the clean look of un-LUTed S-LOG. It's fantastic, plus I get to see exactly what I am recording.
 
I think it is easy to expose.. lump in the middle of the WFM.

Personally I find no lut a bit bright and hard to focus due to lack of contrast.

Thats why I have a SmallHD502.. luts and WFM in all modes.
 
I sure am glad I don't have to lug around a monitor as an exposure tool. And creating a "lump" in the WFM sure doesn't sound very precise. I could probably just eyeball better than the lump.
 
morgan_moore said:
I think it is easy to expose.. lump in the middle of the WFM.

Personally I find no lut a bit bright and hard to focus due to lack of contrast.

Thats why I have a SmallHD502.. luts and WFM in all modes.
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Sounds convinient! I also use this method but with the bare Slog3 image without a lut. I simply open up the iris until I hit the high light warning, from there I start closing the iris until I hit about the middle on the WFM. And the big chunk in the middle on the WFM is always just a bit under the high light warning.

Is this the same way you do it or do you use an MLUT with the WFM?
 
mrchirster said:
liam, i disagree. I was exposung without LUTs for the last half year or so but my footage turned out inconsistent, mostly because in doc style run and gun situations, I would judge the exposure to be right, while it was actually quite underexposed. SLOG3 is tricky to expose without a proper LUT imho
Click to expand...

What method were you using? I hope you weren't 'eyeballing' the Slog. I often shoot run and gun and have no problem setting exposure with Slog.
 
Does anyone here use the 709A LUT ( or one similar) for shooting and exposing whether its burned in or not? Seems to me I get a pretty good idea of what the final is going to look like. I place caucasian faces around 55-60 and Bob's your uncle.
 
Doug the 502 offers a lot more - some of which you may or may not need.
lut in any mode including slogcustom
lut in playback to directir
color analysis
2nd cans output
sdi lead long enough to mount where I want
simple toggle though modes
1080 resolution
option to mount the omboard monotor at rear for basic director monitor
Option to be clean with omboard showing stuff
backup if one fails
etc

with a physical iris and the 502 it is entirel possible to use the camera all day with out visiting the menu.. The pleasure of that cannot be emphasised enough
 
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