FS7: Fs7 cine_ei

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morgan_moore

Major Contributor
I just did a little test on CineEI.

Camera recording Slog3
EVF, LUT800
Zebras at 90%

Exposure set by having a small amount of zebra on the front wing of the car and different EI values.

For 4000 I had to engage full ND, the first a just different stops on 1/4 ND.

Plonk them into CatBrowse and we see three virtually identical images in colour and tone apart from the noise floor on the 4000 is obviously worse.

Investigating recovering the highlights (not seen here) as expected the 500EI file has less to 'get back' (but suprisingly most of the wing could be recovered).

This would appear to stand up my theories on exposure using luts etc to get a clean file.

Full file here.. It is a jpg 12 so would add marginal compression artifacts.
https://dl.dropboxusercontent.com/u/33167160/ei.jpg


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ei.jpg
 
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Taking the files into Resolve which I may screen cap later as expected we can see the three exposures. 'Matching' the three images is trivial using the log wheels, but the EI meta data is lost (as expected)

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This looks as there is a consistent remapping of the exosure values with LUTs
even with different EI values.
If this is true, exposing is much easier as expected.

THX Sam!

Now Sony, let us have the WFM/histo independently of the LUTs!
 
Also, note how the highlights are best in EI4000 and the shadows best at EI500. That's exactly how I'd expect it to be.
 
I did a similar test yesterday but the weather is just shades of grey so I had trouble finding a good highlight.

Even with the terrible light conditions it was pretty clear that if you want shadows lower your EI (I shot EI800) and if you want more highlight room then incease EI (I shot EI4000). Its pretty clear why Sony settled on EI2000 as a good middle ground.
 
Yes,

but this was really expectable.
Expose ETTR like for best signal-noise ratio,
expose under for highlight protection.

BTW: Sometimes you do both at the same time...
 
It's kind of how I shoot my RED. Higher ISO in daylight, to protect the highlightd, lower ISO in low light shoots. Takes a little while to get your head around as it is kind of opposite of what you would think
 
So is this 'smoke and mirrors' .. yes of course.

Shooting Slog with no LUT and putting the white at different levels will protect your speculars and noise your shadows (or the opposite) in exactly the same manner.

I feel, however that viewing with LUT and using EI just make the on location experience a lot more pleasant!

As more software suites hold on to the EI value in the meta data (as CatBrowse does) this methodology will also pass a good start point (intention) to the people doing the post.

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Yoak said:
It's kind of how I shoot my RED. Higher ISO in daylight, to protect the highlightd, lower ISO in low light shoots. Takes a little while to get your head around as it is kind of opposite of what you would think
Click to expand...

It does make my head hurt a little as its the opposite of what I'm used to shooting cameras with much smaller DR and standard gammas.

I have a feeling I will use the hypergammas for any Run & Gun work where speed is of the essence and I can rely on the muscle memory of exposure that I'm used.

I have to say I'm really looking forward to setting up some shoots and testing Slog3 and CineEI to its fullest. It really brings me back to film which I haven't shot since my school days.
 
CineEI will be more useful for quick turnaround projects when Sony
gives us NR and WFM while LUTs being applied to the viewfinder only.

This is what I'm waiting for before testing and deciding if I can use
cineEI for everything...

To be honest: Sometimes when you don't need the full 14 stops range, you can
even expose for lower sensitivities in daylight to have a better SR ratio.
This is best of the two worlds then...
For lowlight I really need in-camera NR!
 
Exposing right is IMO part of the basic camera operating skill. EI helps you do that.

I mean you would sack an EX1 shooter who used 18db-gain and ND64 together right?

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If it's part of the "look" - why not... ;)

ETTR is not so much part of my operating skill sin video.
Knee and black stretch really didn't allow this or you ended up
in awful skintones.
Only the SLog gammas without a "knee" allow for more tolerant
exposure.
More to the right means less noise but also implicates the danger
of blown out highlights in uncontrolled circumstances. When I'm
shooting docos these moments come quite often sothat I'd like to
have a 1-2 stops highlight reserve at least.
Noise isn't really a problem for me as long as it looks kinda natural.

Most of the time I even put some "grain" trough filmconvert in the
footage as I don't like the cleanliness of video.
 
OK I should qualify that - indeed it doesn't work with knee profiles (which I absolutely hate) - Im talking about this camera in Slog3

Understanding and appropriate use is as part of ones tool kit is what I should of said.

Im sure you would agree that EX1+18dbGain+1/64_ND would not be best use of that camera. Equally for a narrow DR scene 2000EI+1/4 ND will not get you as good result as 500+Clear.

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