Since you are using Auto-ISO you may not notice it, but for many cameras, the dual conversion gain helps with noise in shadows.
April 11, 2023
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People who were rich enough to employ servants had the same problem.
Don -
Photons are particles.
But so is dust, which is probably what DonaldB is thinking of.One cause of noise in photos is that the photons arrive at the sensor in a random distribution, like a crowd arriving for a football match, not in an even distribution like soldiers on parade.
Don Cox
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But when you look at Jim’s photographs, he’s an artist. He’s exceptional.
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But in general, the ISO setting matters.
My opinion is that the better answer to ISO and Noise and Exposure questions in general should first be about Lighting. There’s a very important step we all have to take as we progress as photographers, which is developing the ability to “see” light the way the camera will capture it. That is, the difference between how we perceive the living world with our eyes and how it will be rendered as a photograph, and how the lighting impacts it and how we can modify the light or seek out better light to produce better results.
I know this to be true, yet it seems very difficult for other forum experts to say this simple truth. It’s infinitely more important than understanding how photons scatter on a sensor.
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This thread started off quite reasonably, like this:
and after nearly 400 interventions (mostly by the usual suspects)...
I despair
David
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I often include a comment that photography is all about the light. Without light (or some form of electromagnetic radiation) there is no photography.
That observation leads naturally to acknowledging that ISO isn't an exposure setting due to the fact it has no direct effect on exposure.
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That may all be true if the goal is a nice looking sooc jpeg. The lighting is also important for the final image when shooting raw, but ISO is not very important.
But if shooting raw, and if as in my case the aim is to minimise visible noise then ISO has zero influence on how I set the optimal exposure** when hand-holding the camera. When I am ETTRing using a tripod then I lock in base ISO.
How/why I set exposure* the way I do is explained in my "Why are my photos noisy?" thread.
* exposure - amount of light that struck the sensor per unit area while the shutter was open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights. -
iso 4000 raw processed no adjustments. iso 100 pushed to reach the same brightness as the iso 4000 image. the difference is in the shadows. WB is also off shooting underexposed.
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Those images are meaningless because I cannot verify what processing might have been applied to the jpegs.
Post links to the raw files.
The exposures* are clearly different for each image because the scene luminances are different.
* exposure - amount of light that struck the sensor per unit area while the shutter was open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights. -
they are 1 at iso 4000 and the other at iso 100 😁 look at the exif info. thats the shift in WB look at the histogram.
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ISO has nothing to do with it, assuming the values displayed in your jpeg image are not falsified which is very easy to do.
The aperture and shutter speed are the same in both, again assuming you didn't falsify the exif data displayed in the jpeg image, so the difference in exposure* is due to a difference in scene luminance as I described earlier.
Those jpegs could have had strong noise reduction and who knows what other processing applied to them.
You are withholding the raw files so clearly you are hiding something 🙂
* exposure - amount of light that struck the sensor per unit area while the shutter was open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights. -
You are withholding the raw files so clearly you are hiding something 🙂
Do your own tests then as you dont seem to trust anyone so im not wasting my time discussing this any further.
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That's another example of you making statements that are not true.
It is you I don't trust because you have not told the truth on too many occasions in these forums for me to just blindly accept any images you post as being authentic and legitimate.
You are withholding the raw files, which is obviously your choice to make, but who knows what noise reduction or other editing might have been applied to those jpeg images.
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i will PM them to everyone else, but not you. easily fixed ,you dont want to be part of a sensible conversation then i will leave you out.
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No problem, and I assume you are certain no-one will then email them to me as well 😊
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Don, my own experience is that very often your posted 'tests' should be take with a very large pinch of salt. I'm sure that a lot of other users here that have wasted time taking them seriously could attest to the same. we even have examples in the lifetime of DPReview. I for one would not trust them an inch until you published every bit of surrounding information which would allow where the trick is without wasting time.
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I think it's wisest to tread Don's 'demonstrations' as entertaining conundrums, if you enjoy hunting out trickery, not as statements of fact. If you don't enjoy hunting out trickery, just ignore them.
