EX1 Noise In The Shadows?

[Bill Ravens]

Peter...

hope this helps your understanding:
http://www.adobe.com/products/photos...near_gamma.pdf

[Alister Chapman]

With the very close relationship between the EX's cinegammas and Sony's Hypergammas it might be worth taking a look at Sony's guide to Hypergammas. The curves are very similar.

Sony : Digital Cinematography with Hypergamma : United Kingdom

[Michael Maier]

Originally Posted by Alister Chapman

With the very close relationship between the EX's cinegammas and Sony's Hypergammas it might be worth taking a look at Sony's guide to Hypergammas. The curves are very similar.

Sony : Digital Cinematography with Hypergamma : United Kingdom

Do you know how close they actually are to the hypergammas?
Looking at the hypergammas there are only two kinds, for high contrast and for low light with a broadcast safe version and a full dynamic range version of each. The cinegammas don't seem to be like that at all. I have read the article you linked to before, but without knowing how close they are and which cinegamma correspond to which hypergamma its difficult to apply any of that to the EX1.

[Dominik Seibold]

Originally Posted by Michael Maier

I’m assuming the aperture was the same for all gammas right.

Of course.

Originally Posted by Michael Maier

Because to my eyes, Cine4 doesn’t really look as bright as std3 in those pictures.

Yes. The shadows are very similar. But the hightlights are brighter. Actually clipping-bright. ;)

Originally Posted by Michael Maier

Also, looking at your samples, I don’t see why Adam Wilt called cine3 “brighter cine” since cine3 seem to have darker shadows than cine1.

The shadows of cine3 are darker, but the mids and highlights are brighter. So integrated over the whole range cine3 is brighter.

Originally Posted by Michael Maier

But yes, it doesn’t “produce” noise which is not there, but what I obviously meant was which gamma produces the cleanest image with the least visible noise?

Cine3 is the best for low shadow-noise, because it has the darkest shadows of all gammas.
But when I'm talking about that the SNR doesn't change, I try to explain, that the actually captured information is the same. So you can change the gamma in post without (significant) loss.

Originally Posted by Michael Maier

That would only mean that when exposing to high lights using the stds without knee you would capture less info in the shadows because they would be underexposed. It would not necessarily mean the shadows would be noisy.

In terms of SNR the shadows will be more noisy. You can think about std3 without knee is similar to cine1 with 3db extra-gain.

Originally Posted by Michael Maier

If using for example std2 which crushes the blacks you shouldn’t see much noise.

Yes, but you're not only loosing noise but also picture-information. I don't want to loose picture-information, because that's irreversible. You can't undo that in post.

Originally Posted by Michael Maier

I’m talking about dynamic range and or latitude or how many stops of info can be recorded and you are talking about something else ;)

I'm talking about SNR, because dynamic-range/lattitude deduces straight from maximal SNR.

Originally Posted by Michael Maier

How does that explain why you recommend Cine4 for high contrast but use Cine1?

Because the SNR is the same for all cine-gammas, you're capturing almost the same information with each of them. So it's just a matter of taste, whether you want to approximate the final look in the camera or to shoot more linearly done with cine1.

Originally Posted by Michael Maier

So what you meant by “and take noise” is that the cine gammas show less noise?

If you switch from a cine-gamma to a std-gamma without changing the exposure, then the shadow-signal-to-noise-ratio doesn't change (because the amount of light falling onto the sensor stays the same).
-But the clipping point gets lower (because of the std-without-knee-3db-extra-gain-thing), so you're loosing highlight-information.
-When compensating for that by lowering the exposure, the SNR drops.
Choose your favourite.

Originally Posted by Michael Maier

By the way, you totally bypassed my reply about gamma having an effect on low light and the F900R having a hypergamma preset for low light while you said it wasn’t related to gamma. Mind commenting on that?

I commented on that. Look for the word "heuristic" in my last post. ;)
Yes, it makes sense to say that low-light-situations often are low-contrast-situations. So it makes sense to use cine1 on that, because cine1 the has strongest overall-contrast of all cine-gammas.