There are many cameras that the ISO does change the sensitivity via the use of a different amplification in the sensor. Check photonstophotos.net
1 Like
Your link takes me to Claff’s home page with it’s hundreds of page URLs. So it proves nothing to me; do you have something specific to sensors themselves?
I mean, what else would it do? I understand what people are getting at, but if it didn’t change the sensitivity of something, it would be meaningless. Maybe it is only adjusting the sensitivity in software, but it must be adjusting it somewhere.
Hmm… so you’re saying that the gain adjustment corresponds to a behavior of the camera to act as if it is more sensitive to light? I’m still trying to figure out what component of the camera becomes more “sensitive”.
I fully agree with you, that changing the camera’s ISO does not change the sensitivity of the sensor. I do not agree that ‘gain’ is some sort of change that corresponds to sensitivity. The use of the term as such in the camera manuals appears to me to be a half-assed corollary to film photography that the manufacturers believe make their mechanisms easier to use.
I’ve worked with sensors we had to cryo-cool in order to get real improvement to sensitivity, and to try to sell post-capture gain as equivalent would get me thrown out of the room.
Sometimes I will use P mode. I will use P mode when having a special shutter speed or special aperture is not important to the image. It lets me focus on what is truly important to the image in question which is timing and composition. I also tend to shoot with exposure bracketing to ensure one of the exposures will work well. Obviously sports and portraits don’t fit into this category as shutter speed is critical to sports and aperture is critical to portrait.
Exactly, and that is why I used the term in brackets, in the hope that people in this forum would understand that it was short hand for understanding the relation between shutter speed and aperture implications of and the effects of varying these. – but that was seemingly somewhat too optimistic…
Correct!
In most cameras, the ADC is preceded by a Programmable Gain Amplifier chip - often, but not always, included in a so-called Analog Front-End chip.
In other cameras, the ISO setting is carried as metadata in the raw file to the RGB calculation that converts the raw to RGB. In my Foveon-based camera there are three ADCs. With such cameras, the camera is made more “sensitive” in that it take less illuminance at the sensor to to produce a given output … see Standard Output Sensitivity as described here:
As an engineer, for me “gain” was output/input … for example sRGB value/illuminance as above or, for my Sigma camera’s green layer sensor output, seven uV per captured electron.
I’m glad that at least we agree on something. 
2 Likes
And as for the discussion of ISO:
I’ve once read a ISO-standard definition of the meaning of ISO in digital cameras. (As far as I remember, it was fairly abstract, relating to the output and quite open as to how camera manufacturers implemented it.) If somebody has access to it, I believe it would be wise to take this into account on further ISO discussions.
EDIT: I think it was ISO standard 12232:2019.
A clarifying article is found here:
https://www.dpreview.com/articles/9698391814/the-ins-and-outs-of-iso-what-is-iso
++ part 2:
https://www.dpreview.com/articles/5426898916/ins-and-outs-of-iso-where-iso-gets-complex/1
1 Like
Correct Tim. All I’m saying is that your “somewhere” is not the sensor.
1 Like
I have an un-authorized copy of of the 2006 version but I try not quote it on-line.
It does incorporate the following:
And this is about the earlier ISO version:
1 Like
Seemingly so …
I’ve set it to infinity. 
There are 3 values, actually, only vaguely documented.
There’s STD (please don’t resolve the acronym ), MAX (always shoot with the max. aperture) or MTF (Modulation Transfer Function).
You can preset the camera to select the maximum aperture or an aperture value that
achieves the best lens resolution as a combination of shutter speed and aperture value.
1 Like
AFAIK (and I would love to be corrected) on my Canon camera this is the only full-auto mode usable with a flash. If you use Av/Tv the camera considers that the flash is for fill-in and exposes for the available light instead of for what the flash can do.
1 Like
The Lumix LX7 was marketed with high sensitivity sensor, pointing to the ISO range of 1600-12800. Very cool 
! I was confused at first, given the typo, and the closest match I found was this Lunix LX7 Touchscreen Electric Hand Massager. Jesting now complete, the features you describe seem unique. Did you find the MTF setting valuable in a camera that appears designed to be handheld?
Yes, sorry, I was typing on the phone, and missed that glide-typing guess the wrong word.
I rarely inspect my images closely, and mostly shoot manual on that camera, so I cannot say whether it’s a definite improvement or marketing snake-oil. Why would being hand-held make the feature useless?
1 Like
“STD” is not an acronym.
(Please contribute to the fund for buying me a language-pedantry ND-filter implant, LOL)
“P mode …” No, I don’t use it.
I, like so many others, use A mode. I use A mode to keep the aperture wide so that the shutter speed remains as high as possible, Combined with auto iso (with defined limits) and auto-iso minimum shutter speed. I think that’s what Sony calls it: I call it advisory minimum shutter speed, because the camera will go below it if it can’t raise the iso enough. [Confused? …you will be]
It’s not that complicated. Indeed. And coupled with its incredible eye auto focus, leads me to call my Sony a7iv “my expensive point&shoot.”
Film Cameras. Yes. My OM1n’s level of automation extended to to a pointer in the viewfinder. Adjust shutter and/or aperture to keep it centred. Early P Mode.
1 Like
Here, of course not. But it could mean Sexually Transmitted Disease, for example.
2 Likes
Yes, i use it.
I often photograph animals below the water line, and the P-mode is the tool of choice if i expect lighting to change often, which i half of the time don’t even notice because my eyes are underwater, too.
If something unexpected happens it is faster to switch to P than to change aperture, iso and exposure time, and switching back later.
P is mostly useful if you don’t control motive and environment.
3 Likes
I used it on lumix cameras a lot, on fuji I often have everything on automatic with a minimum shutter speed of 1/250, I’d like a minimum aperture setting too but they don’t have that
1 Like
No joke, if you have hand/finger/wrist pain, these things are awesome. I use mine like one a week.
1 Like