Dumb question: Which ISO do you normally shoot at?

Naturalist wrote in post #4006020
I'm from the old school where slower ISO film speed meant less noticeable grain in the finished image so I always had used ISO 25, 50, 64 and 100 film.

Today I carry this habit over and use ISO 100 all the time for less noise.

The new school is, properly exposed, it is nearly impossible to tell the difference in noise up to ISO 400 in most cases. Your mileage may vary with subject and conditions, but in most cases ISO 100 and 200 gain you nothing unless you need a slower shutter speed.

Even ISO 800 noise takes effort to notice unless you have large and/or deep shadow areas. Of course, it depends on what you are trying to achieve, but I think for most images, ISOs 100 and 200 are rarely necessary for maximum IQ.

As low as I possibly can while keeping the shutter speed high enough to handhold the camera (I shoot primarily Av mode). That's what I do most of the time, although there are exceptions depending on light conditions and creative considerations--purposefully using a slower shutter speed to convey motion, for instance. I also don't bother with "in-between" ISOs until I get above 800 when noise starts to become an issue for my use.

Outdoor from 100 to 400
Indoor with flash from 400-1600
Indoor without flash from 3200 or 6400
I have not tried ISO 50 yet, don't know how much IQ gain over ISO 100.
ISO 400 seems to be a good general ISO to use both outdoor and indoor.

The Hardcard wrote in post #4006335
The new school is, properly exposed, it is nearly impossible to tell the difference in noise up to ISO 400 in most cases. Your mileage may vary with subject and conditions, but in most cases ISO 100 and 200 gain you nothing unless you need a slower shutter speed.

Even ISO 800 noise takes effort to notice unless you have large and/or deep shadow areas. Of course, it depends on what you are trying to achieve, but I think for most images, ISOs 100 and 200 are rarely necessary for maximum IQ.

That may be the new school of thought for some, but certainly not all. I shoot with the lowest ISO I can for a given shutter speed and ISO combination so in the event I miss exposure, I have a better chance of recovering the shot with minimal noise.

Mark

i use the lowest possible but i'm not real knotsy about because i use canon cameras .

ed rader

nburwell wrote in post #4006126
Outdoors I have my ISO set between 100-200.

Indoors I bump it up to 400 to 800 (depending on if I'm using a flash or strobes).

How bout those Fightins'

200-400 outdoors, usually, leaving it at around 200 most of the time. Indoors, I start at 640 and move it up, with flash I like to have it around 640.

bbbig wrote in post #4005802
Here's a newbie question,

I usually shoot at lowest possible ISO to obtain the least noisy images. So, unless I want super-fast shutter speed, I am shooting ISO 100 (on my 30D) when I'm outdoors. Indoors, I use ISO 1600 if I don't happen to have a flash attached. Am I doing this right?

What ISOs do you normally use, and why?

I use the lowest that will work with the following provisos:

With a 30D, I use: 160, 320, 640, and 1,250.

These are based on "black noise" testing done originally by John Sheehy (dpreview), and confirmed by myself as being the "best" ISO values to minimize noise on a 30D.

One could not likely tell the difference between these and other values, but the downright anal personality might. I don't believe in anality, but in practice it's easy to use them because they are the 1/3 stop values for ISO so no harm done. Three clicks from any one takes you to the next one.

Occasionally 3,200 or 1,600 when I'm desperate.

Outdoors: ISO 100 - 400
Indoors: ISO 400 - 800
Impossible Looking Shots I Want To Try Anyway: ISO 1600

On the Digital Rebel at least, I don't really see any noise at ISO 100 - 400. ISO 800 starts to show noise, but I'm using it constantly now anyway because it lets me get better shutter speeds for low-light action.

I try to shoot 100 ISO and 100 ISO only. I carry a monopod 80% of the time to compensate the sometimes slow shutter speed. During daylight, obviously isn't too bad. 8 out of 10 times, I'm carrying my equipment with me and a monopod never leaves my side.

xarqi wrote in post #4006298
I read something interesting and convincing on the web recently, but I just cannot find the link now. The upshot was, as I recall, that noise does not increase linearly (technically, monotonically) with ISO, but rather, there are periodic dips to lower noise than would be expected with a linear relationship. On most cameras, these dips are at ISO 100 200 400 800, etc. The explanation given was that these were the "real" sensitivities, while the intermediate settings being derived mathematically. Now - the interesting part is that for the 30D, these were at 160, 320, 640, 1250, etc.
I was convinced. I tend to use these steps now. I'll try to find the link, and post it if I have success.

Half an hour later - found it: link and discussion.
There's more going on here than I understand, so decide for yourself if it's useful.

Hey thanks for that link.

Very interesting about those 160,320,640,1250 ISO settings... Do you see that resulting histogram at those settings are always "spiked"? In other words, unless you shoot at ISO 100/200/400/800/1600, it may result in inaccurate distribution of colors, even though the signal to noise ratio may be better at 160/320/640/1250. Any thoughts?

100 as much as possible, I only go to higher levels if really needed.

Shutter speed and aperture is more important to me than ISO. ISO to support the other two. I shoot in raw, and slightly overexpose, and I have minimal noise. I don't apply any noise reduction. And when I do have noise, it doesn't bother me. But I know some people don't like any noise.

I mainly shoot landscapes / architecture and almost always shoot at 100 and maybe bump it up to 200. Shooting people and pets I'll usually shoot 200 to 400.

I seldom shoot 800 or higher but now that I'm using the 5D I may venture a little higher and see what happens but there was no purpose to use 800 or 1600 or even 400 for that matter with my 10D's as I never liked the results.

Even in film days, if it was over 200, it wasn't in my camera and prefered 64 & 100 ... even 25 back when!

I shoot as low an ISO as I need to get the ss I want. Often outdoors its ISO 100-400, and often indoors for sports I crank it up to ISO 3200...

Esentially the answer is what ever I need to get the shutter speed I want...