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Old November 26th, 2008, 04:58 PM   #16
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Btw, I would interpret the terms "contrast" and "dynamic range" in this way:
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EX1 Noise In The Shadows?-terms.png  
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Old November 27th, 2008, 08:16 PM   #17
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Quote:
Originally Posted by Dominik Seibold View Post
No. The shadows of cine4 and the shadows of the stds are the same. That's the cause why cine4 is called "video bright". Cine1 has much darker shadows (and darker mids) than cine4.
I really had the impression that what seems to get lifted when comparing Cine1 to Cine4 are the mid tones while high lighting handling and shadow detail would stay the same. When I switch between Cine1 and Cine4 my shadows don't seem to change. Just the mid tones. Do this test: Set the camera to auto-iris and point it to a chip chart and watch the mid gray chip. Now change between cine1 and cine4. You will see that the mid gray will vary but the auto-iris will not change the exposure.


Quote:
Originally Posted by Dominik Seibold View Post
With weaker shadow-contrast I mean that the slope/derivation/rise at the lower end of the gamma-curve is more flat, so the shadows look darker. A steep slope of the curve at the lower end would accentuate the shadows, because steep means, that the same change of input results in more change of the output. Flat means the same change of input results in less change of output - and then because we're coming from black (we're talking about the lower end) it looks nearer to black.
If you don't understand me, I can create a graphic for explanation.

So by shadow-contrast you mean shadow gradation?

If not, a graphic would be great ;-)



Quote:
Originally Posted by Dominik Seibold View Post
I don't have problems with IR, although I don't use an IR-filter.

Really? Pretty much every EX1 has IR problems. Are you using a 80a or 80b filter or just bluing all your lights and avoiding tungsten all together? Maybe that could explain why IR wouldn’t affect your camera much as tungsten is most responsible for accentuating IR contamination?


Quote:
Originally Posted by Dominik Seibold View Post
Yes, it's the mistake of the operator to use cine4, if the scene doesn't have much dynamic-range. Flat scenes want to be shot with cine1.
So if I understood you right, you seem to recommend Cine4 for high contrast scenes like a day exterior with lots of shadow and Cine1 for low contrast scenes. But how about low light? Low light is a kind of low contrast and yet cine1 is so bad at it .


To sum it up, what gamma do you think:



Produces less noise?



Records more dynamic range?



Best for High contrast situations?



Best for low light situations?



Best for low contrast situations?
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Old November 27th, 2008, 09:11 PM   #18
 
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from what I've seen, all the cine settings make compromises of some sort. If you want a RAW spectrum captured, that has as much data as this cam/cmos can capture, use a STD setting.(not std2). Then post process to get the best image possible. All the cine settings are compromises to make the monitor look good.

OK, I'm sure I'll get an argument, but, trust me....LOL
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Old November 27th, 2008, 10:41 PM   #19
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Quote:
Originally Posted by Michael Maier View Post
I really had the impression that what seems to get lifted when comparing Cine1 to Cine4 are the mid tones while high lighting handling and shadow detail would stay the same. When I switch between Cine1 and Cine4 my shadows don't seem to change. Just the mid tones. Do this test: Set the camera to auto-iris and point it to a chip chart and watch the mid gray chip. Now change between cine1 and cine4. You will see that the mid gray will vary but the auto-iris will not change the exposure.
Cine4 HAS lighter shadows than cine1 (black of course stays black). I will post a test-image soon.
The auto-iris won't change because the gamma-curves get applied after exposure-measurement.
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Originally Posted by Michael Maier View Post
So by shadow-contrast you mean shadow gradation?

If not, a graphic would be great ;-)
I attached an illustration. I hope that makes things more clear.
(These curves aren't measured but customly set up by my estimation/experience.)
Quote:
Originally Posted by Michael Maier View Post
Are you using a 80a or 80b filter or just bluing all your lights and avoiding tungsten all together?
I don't know the filter-types. They were included with the lights.
I just checked it out again without filters and yes, there are some reddish colors even after white-balance. I guess I oversighted it becauce I was used to that tungsten has very warm colors.
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Originally Posted by Michael Maier View Post
So if I understood you right, you seem to recommend Cine4 for high contrast scenes like a day exterior with lots of shadow and Cine1 for low contrast scenes.
Yes.
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Originally Posted by Michael Maier View Post
But how about low light? Low light is a kind of low contrast and yet cine1 is so bad at it .
No, low light is not concerned with low contrast. Low light is just low light, like a low constant factor before everything. If you put a too strong nd-filter before your cam, even a daylight-situation becomes low-light, but that doesn't change the contrast (ratios between dark and light areas).
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Originally Posted by Michael Maier View Post
Produces less noise?
The gammas don't produce noise (except the stds, read my comment to Bills statement underneath), but are more or less accentuating dark-areas (where the SNR is bad).
Quote:
Originally Posted by Michael Maier View Post
Records more dynamic range?
Cine1-4 record basically the same dynamic range. But the stds without knee have less dynamic range, because they're throwing away sensor-range which was left as dynamic headroom for knee (see attached illustration).
Quote:
Originally Posted by Michael Maier View Post
Best for High contrast situations?
Cine4. Or cine1 with slight underexposing and compensation for that in post (my preferred way).
I don't like cine3 a lot, because it's got some built-in negative black stretch.
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Originally Posted by Michael Maier View Post
Best for low light situations?
Is not concerned with gamma-curves. If it gets dark, you need gain/different exposure-settings - not a different gamma.
Quote:
Originally Posted by Michael Maier View Post
Best for low contrast situations?
Cine1.
Quote:
Originally Posted by Bill Ravens View Post
If you want a RAW spectrum captured, that has as much data as this cam/cmos can capture, use a STD setting.
No, stds without knee are wasting sensor-range (see attached illustration) and so are downgrading SNR. With properly set knee they are not neutral ("raw") any more.
Attached Thumbnails
EX1 Noise In The Shadows?-ex1-gamma-sketches.png  

Last edited by Dominik Seibold; November 28th, 2008 at 12:26 AM.
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Old November 28th, 2008, 05:04 AM   #20
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Dominik, it has been an useful and interesting conversation. But I’m still confused with what you are trying to say, especially that you seem to be starting to contradict some of your earlier posts.

Quote:
Originally Posted by Dominik Seibold View Post
Cine4 HAS lighter shadows than cine1 (black of course stays black). I will post a test-image soon.
I’m looking forward to the images then. Because on my tests, shadows didn’t change and I’m not talking blacks.


Quote:
Originally Posted by Dominik Seibold View Post
I attached an illustration. I hope that makes things more clear.
(These curves aren't measured but customly set up by my estimation/experience.)
Thanks for the graphics. I think I understand what you mean by shadow-contrast or high light contrast. It’s what I would refer to gradation or how much difference you see in the shadows or high lights as in, do they clip abruptly or gradually. Right?

Quote:
Originally Posted by Dominik Seibold View Post
I don't know the filter-types. They were included with the lights.
I just checked it out again without filters and yes, there are some reddish colors even after white-balance. I guess I oversighted it becauce I was used to that tungsten has very warm colors.
This is what I thought. Maybe a 80 filter on the lens instead of the IR one would be a better move as it would potentially “cure” two problems with one strike? Although the 80 filters cut 2 stops. Not sure how much the 486 or the new IR filter cuts if any.

Quote:
Originally Posted by Dominik Seibold View Post
No, low light is not concerned with low contrast.
Well, low light means not enough light for an exposure yes, but most low light tend to be low contrast especially indoors.

Quote:
Originally Posted by Dominik Seibold View Post
The gammas don't produce noise (except the stds, read my comment to Bills statement underneath), but are more or less accentuating dark-areas (where the SNR is bad).
That’s noise. If Cine4 is indeed brighter in the shadows it means it is lifting the blacks and if it is lifting the blacks it will produce more noise in the shadows. You said it yourself earlier that Cine1 is cleaner in the shadows right? You were talking about noise I thought here:

Quote:
Originally Posted by Dominik Seibold View Post
Cine4 and the stds are bad, because they've got a high shadow-contrast, so the noise in there gets even more accentuated.
So for you, which of the gammas produce less noise?

Quote:
Originally Posted by Dominik Seibold View Post
Cine1-4 record basically the same dynamic range.
I don’t understand how they can all record the same dynamic range in your opinion when you say Cine4 records more info in the blacks. That would mean it records more dynamic range than Cine1 for example. If you recommend Cine4 for high contrast it also means it records more dynamic range. Or?

Quote:
Originally Posted by Dominik Seibold View Post
Cine4. Or cine1 with slight underexposing and compensation for that in post (my preferred way).
By compensating in post you mean lifting the blacks? This will cause noise. Or did I miss understood you?

And so you recommend Cine4 for high contrast but use Cine1?

Quote:
Originally Posted by Dominik Seibold View Post
I don't like cine3 a lot, because it's got some built-in negative black stretch.
I thought Cine4 had built in black stretch, if it produces brighter shadows .

Quote:
Originally Posted by Dominik Seibold View Post
Is not concerned with gamma-curves. If it gets dark, you need gain/different exposure-settings - not a different gamma.
Actually, it is. This is the reason the F900R and F23 have hypergammas for high contrast and for low light. If it was not related to gamma why would there be a hypergamma for low light?

By the way, I found a post by you from another thread which I don’t understand either. :)

Here it is:
Quote:
Originally Posted by Paul Kellett

I found that the cine's took too much light.
Quote:
Originally Posted by Dominik Seibold View Post
...and take noise. ;)
Btw, that's true for cine1-3, but not for cine4, because it's "video-bright", meaning that its slope on the lower end is identical to that of the stds.
What do you mean by “and take noise”?
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Old November 28th, 2008, 05:25 AM   #21
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Quote:
Originally Posted by Bill Ravens View Post
from what I've seen, all the cine settings make compromises of some sort. If you want a RAW spectrum captured, that has as much data as this cam/cmos can capture, use a STD setting.(not std2). Then post process to get the best image possible. All the cine settings are compromises to make the monitor look good.

OK, I'm sure I'll get an argument, but, trust me....LOL
Bill, what std gamma do you use and what knee, black, black gamma etc settings to get the widest dynamic range or RAW as you put it?
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Old November 28th, 2008, 06:05 AM   #22
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Interesting discussion. It seems Dominik (whose observations / opinions I share almost 100%), gives the term "contrast" a meaning I proposed, which was rejected by Michael :)
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Old November 28th, 2008, 06:09 AM   #23
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STD gammas are producing some very strange white lines (halos?) in high contrast areas.
So I won't recommend using them.


Dennis
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Old November 28th, 2008, 07:51 AM   #24
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Quote:
Originally Posted by Michael Maier View Post
I’m looking forward to the images then. Because on my tests, shadows didn’t change and I’m not talking blacks.
Comparison is attached, and cine4s shadows ARE lighter.
Quote:
Originally Posted by Michael Maier View Post
It’s what I would refer to gradation or how much difference you see in the shadows or high lights as in, do they clip abruptly or gradually. Right?
Yes. Hopefully they don't clip.
Quote:
Originally Posted by Michael Maier View Post
, but most low light tend to be low contrast especially indoors.
That heuristic is of course true.
Quote:
Originally Posted by Michael Maier View Post
if it is lifting the blacks it will produce more noise in the shadows.
It's not producing, but accentuating, because the signal-to-noise doesn't change, because the the picture-information in those shadows gets amplified, too.
Quote:
Originally Posted by Michael Maier View Post
So for you, which of the gammas produce less noise?
Again, the cines are all identical in terms of signal-to-noise-ratio. But the stds without knee lower the clipping-point, so you have to recude the exposure to capture the same highlight-information, and so you are reducing the signal-to-noise-ratio in all picture-areas.
Quote:
Originally Posted by Michael Maier View Post
I don’t understand how they can all record the same dynamic range in your opinion when you say Cine4 records more info in the blacks. That would mean it records more dynamic range than Cine1 for example. If you recommend Cine4 for high contrast it also means it records more dynamic range. Or?
Theoretically, as long as an used gamma-curve does/can have an inverse, it can't destroy information. Practically, there's quantization-noise especially caused by the mpeg2-compression, which compression-technique is build on reducing quantization-precision on frequency-components which are rated as "less important" for our human visual system. But experience shows that all gamma-curves are accentuating the shadows/shadow-noise so much, that the quantization-noise is almost negligible compared to shadow-noise.
Quote:
Originally Posted by Michael Maier View Post
And so you recommend Cine4 for high contrast but use Cine1?
There are different ways to to judge right exposure:
-no highlight-information is gone
-the average brightness is middle-gray
-the main-subject in the picture is exposured well
If you use the first, then it doesn't make a difference which (cine-)gamma-curve you choose.
If you take the second, then it does matter. But because you can do all that gamma-stuff in post, you should concentrate on capturing most relevant information, which almost doesn't deppend on the (cine-)gamma. "Relevant" shall express, that capturing all highlight-information can be a bad idea, if your (darker) main-subject then vanishes in noise.
Quote:
Originally Posted by Michael Maier View Post
I thought Cine4 had built in black stretch, if it produces brighter shadows .
I said that cine3 has "negative", so the opposite of, black-stretch, so cine3 makes shadows darker. Cine3 also has more highlight-compression than cine1. So it's a very unneutral gamma, but I want to capture pictures neutrally, so I don't like it.
Quote:
Originally Posted by Michael Maier View Post
What do you mean by “and take noise”?
The cine-gammas use more of the available sensor-range than the stds (without knee), so they must look darker, because what a std shows as white the a cine shows as gray, and what a cine shows as white a std shows as clipped.
Using more sensor-range allows to use more of the available light by increasing exposure. But increasing exposure won't increase sensor-noise, so the signal-to-noise-ratio increases.
Attached Thumbnails
EX1 Noise In The Shadows?-ex1-gamma-comparison.png  
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Old November 28th, 2008, 07:55 AM   #25
 
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sorry, guys. got pulled into this discussion once before. not this time.
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Old November 28th, 2008, 08:42 AM   #26
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Quote:
Originally Posted by Dominik Seibold View Post
Comparison is attached, and cine4s shadows ARE lighter.
I see it. Weird that in tests I did using a waveform monitor I could only see difference in the mids. I will have to retest that.

I’m assuming the aperture was the same for all gammas right. Because to my eyes, Cine4 doesn’t really look as bright as std3 in those pictures. It seems just a bit darker than std3 in the shadows. At least less contrasty in the shadows, to try to speak in your terms :)
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.
Quote:
Originally Posted by Dominik Seibold View Post
It's not producing, but accentuating, because the signal-to-noise doesn't change, because the the picture-information in those shadows gets amplified, too.
I guess one of the things which is making it so confusing is the technicalities which clearly are what is keeping us from getting to a common understanding because we don’t seem to agree on the technical terms here. 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?
Quote:
Originally Posted by Dominik Seibold View Post
Again, the cines are all identical in terms of signal-to-noise-ratio. But the stds without knee lower the clipping-point, so you have to recude the exposure to capture the same highlight-information, and so you are reducing the signal-to-noise-ratio in all picture-areas.
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. If using for example std2 which crushes the blacks you shouldn’t see much noise.

But what you are saying is all cine gammas has the same amount of visible noise?
:
Quote:
Originally Posted by Dominik Seibold View Post
Theoretically, as long as an used gamma-curve does/can have an inverse, it can't destroy information. Practically, there's quantization-noise especially caused by the mpeg2-compression, which compression-technique is build on reducing quantization-precision on frequency-components which are rated as "less important" for our human visual system. But experience shows that all gamma-curves are accentuating the shadows/shadow-noise so much, that the quantization-noise is almost negligible compared to shadow-noise.
Here we got lost again. 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 ;)
Quote:
Originally Posted by Dominik Seibold View Post
There are different ways to to judge right exposure:

-no highlight-information is gone

-the average brightness is middle-gray

-the main-subject in the picture is exposured well

If you use the first, then it doesn't make a difference which (cine-)gamma-curve you choose.

If you take the second, then it does matter. But because you can do all that gamma-stuff in post, you should concentrate on capturing most relevant information, which almost doesn't deppend on the (cine-)gamma. "Relevant" shall express, that capturing all highlight-information can be a bad idea, if your (darker) main-subject then vanishes in noise.
How does that explain why you recommend Cine4 for high contrast but use Cine1?
Quote:
Originally Posted by Dominik Seibold View Post
The cine-gammas use more of the available sensor-range than the stds (without knee), so they must look darker, because what a std shows as white the a cine shows as gray, and what a cine shows as white a std shows as clipped.

Using more sensor-range allows to use more of the available light by increasing exposure. But increasing exposure won't increase sensor-noise, so the signal-to-noise-ratio increases.
So what you meant by “and take noise” is that the cine gammas show less noise?

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?

Dominik, although I think this is an useful discussion, let try to be objective rather than getting lost in technicalities which will probably just add more confusion as it’s clear there are some words getting lost in translation here. ;)

The shorter way sometimes is the better one.

Cheers.

Mike


I

Last edited by Michael Maier; November 28th, 2008 at 09:35 AM.
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Old November 28th, 2008, 08:43 AM   #27
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sorry, guys. got pulled into this discussion once before. not this time.
Ok Bill, without getting pulled into the debate, do you mind giving your settings?
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Old November 28th, 2008, 08:45 AM   #28
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Interesting discussion. It seems Dominik (whose observations / opinions I share almost 100%), gives the term "contrast" a meaning I proposed, which was rejected by Michael :)
No rejecting Piotr. Just trying to find a common ground so I can understand where he is coming from and what he means ;-)
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Old November 28th, 2008, 08:54 AM   #29
 
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Michael...

Lighting situations, especially outside, are wide and varied. You're right about knee and slope. Every situation requires custom tuning. Really can't provide a "one size fits all" for you. Setting up requires judicious use of the histogram and the zebra's. The non-linear nature of the way gamma is applied really demands that over-exposure be carefully controlled. I'd MUCH rather under-expose than over-expose.
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Old November 28th, 2008, 09:51 AM   #30
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Ah, how easy was life when we still used old "chemical" film ;-)
Underexposed slide films (positive) and overexposed negative films. Sooo easy.
I have now clue what to do with video. P.
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