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Chato

Chato

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Ok, I am FINALLY convinced that increasing the gain of sensors by raising ISO is not the same as ISO in film. Iliah finally overcame my obtuseness. But I STILL recommend shooting in higher ISO's in dim light.

Why?

Because conducting an experiment to convince myself that I was wrong, I had a hell of a hard time in Adobe Raw making my ISO 100 image look decent. I had to lower the shadows, lower the color saturation, etc. Whereas the ISO 1600 image needed almost no adjustment. So, there IS an advantage in shooting at the higher ISO.
 
Last edited:
Chato said:
Ok, I am FINALLY convinced that increasing the gain of sensors by raising ISO is not the same as ISO in film. Iliah finally overcame my obtuseness. But I STILL recommend shooting in higher ISO's in dim light.

Why?

Because conducting an experiment to convince myself that I was wrong, I had a hell of a hard time in Adobe Raw making my ISO 100 image look decent. I had to lower the shadows, lower the color saturation, etc. Whereas the ISO 1600 image needed almost no adjustment. So, there IS an advantage in shooting at the higher ISO.
Click to expand...
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
 
Chato said:
Because conducting an experiment to convince myself that I was wrong, I had a hell of a hard time in Adobe Raw making my ISO 100 image look decent. I had to lower the shadows, lower the color saturation, etc.
Click to expand...
Some years ago, when I started shooting my daughter's hockey/skating practices, I found the value of Auto ISO in M mode ... except my camera didn't have it :) I would pick a fixed ISO and end up with shutter speeds that varied and realized that some of those could have been shot at a lower ISO. So then, one week, I tried shooting them all at the lowest ISO I expected to use and had to adjust in PP. I found this to be a ridiculous exercise in wasted time - for one thing, the darkest images gave me a useless review image. Unnecessarily having to adjust 60 or so photos at a time was annoying enough, but I found the same thing you did - a simple exposure adjustment didn't do it - I ended up needing to adjust the curve to get the image to look natural, and it the specific adjustments varied from image to image.

This was with a Sony A700 (old 12MP APS-C sensor) and whatever version of Lightroom was current at the time, so maybe things could be different now. But it wasn't long after that that I switched to Nikon to start shooting Auto ISO in M and I haven't looked back. (Not shooting hockey any more, but I use that mode most any time I'm shooting above base ISO).
- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
 
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
 
Dennis said:
Chato said:
Because conducting an experiment to convince myself that I was wrong, I had a hell of a hard time in Adobe Raw making my ISO 100 image look decent. I had to lower the shadows, lower the color saturation, etc.
Click to expand...
Some years ago, when I started shooting my daughter's hockey/skating practices, I found the value of Auto ISO in M mode ... except my camera didn't have it :) I would pick a fixed ISO and end up with shutter speeds that varied and realized that some of those could have been shot at a lower ISO. So then, one week, I tried shooting them all at the lowest ISO I expected to use and had to adjust in PP. I found this to be a ridiculous exercise in wasted time - for one thing, the darkest images gave me a useless review image. Unnecessarily having to adjust 60 or so photos at a time was annoying enough, but I found the same thing you did - a simple exposure adjustment didn't do it - I ended up needing to adjust the curve to get the image to look natural, and it the specific adjustments varied from image to image.

This was with a Sony A700 (old 12MP APS-C sensor) and whatever version of Lightroom was current at the time, so maybe things could be different now. But it wasn't long after that that I switched to Nikon to start shooting Auto ISO in M and I haven't looked back. (Not shooting hockey any more, but I use that mode most any time I'm shooting above base ISO).

- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Click to expand...
When I took a look at the ISO 100 image in Adobe, at first I said, "Aha, these idiots don't know what their talking about. This image SUCKS!."

Then, to be fair I started playing with the controls. And after this and that time consuming adjustment, by golly, you couldn't tell the ISO 100 from the 1600.

Fine. But as you say above, What a pain in the butt to do if you're taken a lot of images!... :-D
 
Dennis said:
Chato said:
Because conducting an experiment to convince myself that I was wrong, I had a hell of a hard time in Adobe Raw making my ISO 100 image look decent. I had to lower the shadows, lower the color saturation, etc.
Click to expand...
Some years ago, when I started shooting my daughter's hockey/skating practices, I found the value of Auto ISO in M mode ... except my camera didn't have it :) I would pick a fixed ISO and end up with shutter speeds that varied and realized that some of those could have been shot at a lower ISO. So then, one week, I tried shooting them all at the lowest ISO I expected to use and had to adjust in PP. I found this to be a ridiculous exercise in wasted time - for one thing, the darkest images gave me a useless review image. Unnecessarily having to adjust 60 or so photos at a time was annoying enough, but I found the same thing you did - a simple exposure adjustment didn't do it - I ended up needing to adjust the curve to get the image to look natural, and it the specific adjustments varied from image to image.

This was with a Sony A700 (old 12MP APS-C sensor) and whatever version of Lightroom was current at the time, so maybe things could be different now. But it wasn't long after that that I switched to Nikon to start shooting Auto ISO in M and I haven't looked back. (Not shooting hockey any more, but I use that mode most any time I'm shooting above base ISO).

- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Click to expand...
A favorite topic of mine ... shooting hockey and skating in the poorly lit arenas typical of youth sports. We had two boys go through youth and high school hockey together, and I've got the image library to prove it.

What I learned the hard way is that manual exposure is the way to go for shooting these types of events. While the lighting is normally pretty lousy, it's at least basically even across the ice. So once you have dialed in an exposure and white balance, you can basically use it for the entire session. The trouble with auto exposure, whether A, S, or auto-ISO, is that your camera is adjusting the exposure under the assumption of basically uniform subject material in changing lighting conditions. What you're shooting is changing subjects under uniform lighting. So you end having to PP each image back to the same exposure.

My routine was to setup during the practice period. First dial in the manual exposure trying to get a workable tradeoff among shutter speed and ISO. Then set exp. comp to about -3 and do a white balance ... arena lighting is usually far off white. So setting a manual white balance also reduces PP. Then set exp. comp back to 0 and shoot away.
 
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Has that realization changed the way you take pictures? One of the primary considerations for me when choosing camera settings is the straight-from-the-camera brightness of my pictures (I do not want to fiddle with that later in an image editing program). ISO 400 needs less exposure than ISO 200 to result in the same image brightness, so even if it is amplification rather than a change in the nature of the sensor itself, the effective sensitivity of my camera has changed with the ISO setting.
 
Last edited:
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Nope. Photons are quanta, they can't be amplified. It's actually quite an important point, because in the main noise is determined by the number of photons captured. The voltage output of the sensor represents that number of photons. Amplifying it doesn't change the number of photons, it just changes the 'exchange rate'.

The whole identification of ISO with gain is bogus. Unfortunately, it's also a brainworm. Once people adopt the idea, it's really hard to get rid of it.
 
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Photons can't be amplified.

And you don't need to amplify them. All you need to do is specify is how the number of photons captured should be translated into tones in the final image. That has nothing to do with gain.
 
Dennis said:
Chato said:
Because conducting an experiment to convince myself that I was wrong, I had a hell of a hard time in Adobe Raw making my ISO 100 image look decent. I had to lower the shadows, lower the color saturation, etc.
Click to expand...
Some years ago, when I started shooting my daughter's hockey/skating practices, I found the value of Auto ISO in M mode ... except my camera didn't have it :) I would pick a fixed ISO and end up with shutter speeds that varied and realized that some of those could have been shot at a lower ISO. So then, one week, I tried shooting them all at the lowest ISO I expected to use and had to adjust in PP. I found this to be a ridiculous exercise in wasted time - for one thing, the darkest images gave me a useless review image. Unnecessarily having to adjust 60 or so photos at a time was annoying enough, but I found the same thing you did - a simple exposure adjustment didn't do it - I ended up needing to adjust the curve to get the image to look natural, and it the specific adjustments varied from image to image.
Click to expand...
That's a problem with the way the tools are designed rather than the operation itself. It's something you really want to do at the processing, rather than the post-processing stage, and some raw processors will do it automatically.
Dennis said:
This was with a Sony A700 (old 12MP APS-C sensor) and whatever version of Lightroom was current at the time, so maybe things could be different now. But it wasn't long after that that I switched to Nikon to start shooting Auto ISO in M and I haven't looked back. (Not shooting hockey any more, but I use that mode most any time I'm shooting above base ISO).

- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Click to expand...
 
Jeff said:
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Photons can't be amplified.

And you don't need to amplify them. All you need to do is specify is how the number of photons captured should be translated into tones in the final image. That has nothing to do with gain.
Click to expand...
 
jrtrent said:
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Has that realization changed the way you take pictures? One of the primary considerations for me when choosing camera settings is the straight-from-the-camera brightness of my pictures (I do not want to fiddle with that later in an image editing program). ISO 400 needs less exposure than ISO 200 to result in the same image brightness, so even if it is amplification rather than a change in the nature of the sensor itself, the effective sensitivity of my camera has changed with the ISO setting.
Click to expand...
Not at all, although obviously I haven't had much time to take pictures... :-)

I don't know about your camera. My Sigma DP2M is basically noiseless at ISO's from 100 to 400, and I never had any intent to change settings.



With my Nikon's I set the ISO to match the light and STILL give me a fast enough shutter speed to eliminate blur on moving objects. The greater the light, the lower the ISO. I have no reason to change that as well.
 
bobn2 said:
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Nope. Photons are quanta, they can't be amplified. It's actually quite an important point, because in the main noise is determined by the number of photons captured. The voltage output of the sensor represents that number of photons. Amplifying it doesn't change the number of photons, it just changes the 'exchange rate'.

The whole identification of ISO with gain is bogus. Unfortunately, it's also a brainworm. Once people adopt the idea, it's really hard to get rid of it.
Click to expand...
At this point I'll be happy to accept any technical explanation. But isn't what you say above, for all practical purposes the same thing?
 
Chato said:
Ok, I am FINALLY convinced that increasing the gain of sensors by raising ISO is not the same as ISO in film. Iliah finally overcame my obtuseness. But I STILL recommend shooting in higher ISO's in dim light.

Why?

Because conducting an experiment to convince myself that I was wrong, I had a hell of a hard time in Adobe Raw making my ISO 100 image look decent. I had to lower the shadows, lower the color saturation, etc. Whereas the ISO 1600 image needed almost no adjustment. So, there IS an advantage in shooting at the higher ISO.
Click to expand...
Camera manufacturers know their cameras, but there have always been sellers of aftermarket software "solutions" who'll see an opportunity to sell a magic bullet. Claim the hardware guys do things suboptimally, whatever. Whether it is NR, a raw developer or an "emulation pack". If all you have is a hammer, you treat everything you see as a nail. This reminds me of the naff noise reduction plugins in the last decade.
 
Last edited:
Jeff said:
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Photons can't be amplified.

And you don't need to amplify them. All you need to do is specify is how the number of photons captured should be translated into tones in the final image. That has nothing to do with gain.
Click to expand...
Don't bother. He is just nitpicking words with more imprecise words.
 
The rink my daughter skated in most often had a brighter end and a darker end - there were banks of lights overhead (some variation between them) but the rink was in a standalone "building" and one end was all plexiglas panels (the other end had to be walled off to make space for scoreboard, zamboni garage, changing rooms, etc.)

So Auto ISO in M with exposure compensation dialed in to compensate for all that white ice did a pretty good job. I didn't mind having to adjust the occasional shot. When I switched from Sony to Nikon (to get auto ISO in M) Canon didn't offer exposure compensation in that mode (not without going to a pro model) so I became a Nikon user by default!

- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
 
Chato said:
Ok, I am FINALLY convinced that increasing the gain of sensors by raising ISO is not the same as ISO in film.
Click to expand...
It never was. Films of different ISOs have different physical properties.

Sensor stays the same, no matter how the signal is amplified.

I think better film/digital analogy is between digital gain and film pull/push processing, where you squeeze that extra from an existing film.

In the end, it does not really matter what we call it or what analogies are made.
 
bobn2 said:
That's a problem with the way the tools are designed rather than the operation itself. It's something you really want to do at the processing, rather than the post-processing stage, and some raw processors will do it automatically.
Click to expand...
I'm sure I've said it before, but what I'd really like is an option for the camera to record a jpeg (if you shoot raw+jpeg ... or the imbedded preview) at the set (or calculated in Auto mode) ISO and the RAW file at base ISO with the intended ISO saved as a setting with a flag telling the software to "apply" that ISO.

- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
 
Dennis said:
The rink my daughter skated in most often had a brighter end and a darker end - there were banks of lights overhead (some variation between them) but the rink was in a standalone "building" and one end was all plexiglas panels (the other end had to be walled off to make space for scoreboard, zamboni garage, changing rooms, etc.)

So Auto ISO in M with exposure compensation dialed in to compensate for all that white ice did a pretty good job. I didn't mind having to adjust the occasional shot. When I switched from Sony to Nikon (to get auto ISO in M) Canon didn't offer exposure compensation in that mode (not without going to a pro model) so I became a Nikon user by default!

- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com
Click to expand...
My best luck with youth sports in general, and hockey in particular, was to simply turn off all the auto-exposure features, including white balance. Then take a few minutes before the start to tune in the exposure using histograms and test shots, and dial in the white balance either using the ice or a white board. It's basically old-fashioned incident light metering. Shooting a color checker really helps set up the PP adjustments.

Sometimes the lighting is uneven, either illuminance or worse, color. Then it really becomes a chore. There were a few arenas where I just didn't bother shooting because the PP headaches weren't worth the trouble.
 
Chato said:
bobn2 said:
Chato said:
jrtrent said:
Perhaps each camera is different. With mine, images shot any higher than ISO 400 are going to be unacceptably noisy to me, and images shot at ISO 200 (my camera's lowest setting) have more clipped highlights than those shot at ISO 400, so my camera stays at ISO 400 all the time. In light too dim for handheld exposures at that ISO, I either mount a flash or put the camera away. Following this procedure, noise is never an issue, and I never have to think about ISO.
Click to expand...
I'm sure they are.

But what was beaten into my head was that raising the ISO does NOT Raise the sensitivity of the sensor. What it does is increase the amplification of the photons that the sensor receives.
Click to expand...
Nope. Photons are quanta, they can't be amplified. It's actually quite an important point, because in the main noise is determined by the number of photons captured. The voltage output of the sensor represents that number of photons. Amplifying it doesn't change the number of photons, it just changes the 'exchange rate'.

The whole identification of ISO with gain is bogus. Unfortunately, it's also a brainworm. Once people adopt the idea, it's really hard to get rid of it.
Click to expand...
At this point I'll be happy to accept any technical explanation. But isn't what you say above, for all practical purposes the same thing?
Click to expand...
I'll butt in and take a shot at this.

Suppose a particular monochrome pixel records 734 photons. What grey tone should that correspond to in your final image? Is that near black, dark grey, middle grey, light grey, near white? Can you tell just from the number of photons recorded?

Of course not. You weren't given enough information to answer the question. If you convert that 734 to a voltage, say 0.734 volts, you still don't know. Amplify the voltage using a gain of 2, or any other number, and you still don't know. Gain, by itself, doesn't add any information regarding the final image.

But if you say that 734 photons should be middle grey in the final image, then we're making real progress. That's what you do when you specify ISO ... you're telling your camera how to process the measured signal to produce a final image, whether that image is digital file in the jpeg standard, or ink on paper.

The point is that is that gain and amplification may be part of the electronic signal processing inside the camera, but the resulting voltages have no meaning until you specify a relationship to the image using ISO.
 
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