Typically, the higher the ISO, the higher the noise - that will be true within any closed system. Quality optics and imagers with large cells and high quantum efficiency will allow shorter exposure times with the same ISO.
In any case, you are correct. A typical high end camera system will pick ISO's that favor picture quality. A photographer will pick settings for the moment.
On a side note, many moons back I had a project where they wanted to know if we could image a fast moving object (on industrial equipment) and I was able to get to an effective shutter speed of 1/2000000. The camera couldn't do it - that required specialized lighting. Jitter in the system required a camera shutter of around 1/20000.
When I worked on my PhD, digital cameras were first hitting the scene (I used conventional B&W film). I looked into converting my equipment to digital. At the time I believe Canon was selling an 8 megapixel digital camera for about $8,000. The conventional B&W film was equivalent to about 34 megapixels (resolution of about 5 microns). I just checked and 400 megapixel digital cameras are out there, if you want to pay around $8,000 :) Pretty interesting that state of the art digital cameras cost about the same as almost 30 years ago, but with 50x the resolution.
Typically, the higher the ISO, the higher the noise - that will be true within any closed system. Quality optics and imagers with large cells and high quantum efficiency will allow shorter exposure times with the same ISO.
In any case, you are correct. A typical high end camera system will pick ISO's that favor picture quality. A photographer will pick settings for the moment.
On a side note, many moons back I had a project where they wanted to know if we could image a fast moving object (on industrial equipment) and I was able to get to an effective shutter speed of 1/2000000. The camera couldn't do it - that required specialized lighting. Jitter in the system required a camera shutter of around 1/20000.
I'm so old I still remember the day I traded in my pterodactyl chisel box for a canon 35mm.
LOL. I worked with digital cameras before they hit the consumer market.
Edit - maybe I should qualify that statement. VCR video cameras were all the rage then, so technically....not quite true.
When I worked on my PhD, digital cameras were first hitting the scene (I used conventional B&W film). I looked into converting my equipment to digital. At the time I believe Canon was selling an 8 megapixel digital camera for about $8,000. The conventional B&W film was equivalent to about 34 megapixels (resolution of about 5 microns). I just checked and 400 megapixel digital cameras are out there, if you want to pay around $8,000 :) Pretty interesting that state of the art digital cameras cost about the same as almost 30 years ago, but with 50x the resolution.
$8K for a camera - I've spent more than that on a single lens. Fortunately, it was the company's money.