Auto ISO or manual ISO (Page 2): It's really a chicken and egg situation. If you let the camera pick an ISO compatible with the exposure you have set when there is little light the...

selmslie Loc: Fernandina Beach, FL, USA

Ysarex wrote:

... If you're concerned about noise then you need to change shutter and/or f/stop because those are what determine noise, not ISO.

Joe

It's really a chicken and egg situation.

If you let the camera pick an ISO compatible with the exposure you have set when there is little light the camera might pick an ISO that's too high.

There are only two ways to control this. Either set an upper limit for the Auto ISO and add exposure if the image is too dark or pick an ISO where you get no more noise than you can tolerate and adjust the exposure.

Ysarex Loc: St. Louis

selmslie wrote:

It's really a chicken and egg situation.

It's really a situation of noise is caused by exposure not ISO. The two are related but keeping cause and effect straight helps you make better choices.

selmslie Loc: Fernandina Beach, FL, USA

Ysarex wrote:

It's really a situation of noise is caused by exposure not ISO. The two are related but keeping cause and effect straight helps you make better choices.

We know noise is cause by insufficient exposure. But if the ISO is too high it will facilitate insufficient exposure. That't the tradeoff.

Grahame Loc: Fiji

Here we go again, another thread with the schoolgirl bickering between these two.

Linda From Maine Loc: Yakima, Washington

Grahame wrote:

Here we go again, another thread with the schoolgirl bickering between these two.

Page 1 responses covered the opening topic thoroughly, and includes the UHH-mandatory repetitive replies and contradictory advice. What else is there? Let the boys play 😊

Grahame Loc: Fiji

Linda From Maine wrote:

Page 1 responses covered the opening topic thoroughly, and includes the UHH-mandatory repetitive replies and contradictory advice. What else is there? Let the boys play 😊

Now there's an idea, a 'Play Section'

srt101fan

selmslie wrote:

We know noise is cause by insufficient exposure. But if the ISO is too high it will facilitate insufficient exposure. That't the tradeoff.

Come on, Scotty... the topic is excessively high ISOs selected by the camera when set to Auto ISO. How does this "facilitate insufficient exposure"?

selmslie Loc: Fernandina Beach, FL, USA

srt101fan wrote:

Come on, Scotty... the topic is excessively high ISOs selected by the camera when set to Auto ISO. How does this "facilitate insufficient exposure"?

I think we all know the answer. It just depends on which one you pick first.

If you start with a high ISO you are probably going to end up with a low exposure.

If you start with a low exposure you are probably going to need a high ISO.

That’s why the images with the least noise are scenes with plenty of light.

It’s not such a difficult concept.

srt101fan

Linda From Maine wrote:

Page 1 responses covered the opening topic thoroughly, and includes the UHH-mandatory repetitive replies and contradictory advice. What else is there? Let the boys play 😊

Thanks, Linda! Just ring the bell when it's Miller time.....

srt101fan

selmslie wrote:

I think we all know the answer. It just depends on which one you pick first.

If you start with a high ISO you are probably going to end up with a low exposure.

If you start with a low exposure you are probably going to need a high ISO.

That’s why the images with the least noise are scenes with plenty of light.

It’s not such a difficult concept.

Either you miss the point.... or, more likely you go off point to give yourself more room for satisfying your need for arguing....

selmslie Loc: Fernandina Beach, FL, USA

srt101fan wrote:

Either you miss the point.... or, more likely you go off point to give yourself more room for satisfying your need for arguing....

So are you voting for the chicken or the egg?

BebuLamar

Steve Carlson wrote:

90% of the time I shot in manual with auto ISO. I always take a test shot of subject, look at histogram and make adjustments with aperture and shutter speed. Yesterday in LR I was making adjustments to a photograph I stood in the middle of a cloudy day and noticed ISO was went to 2500. Seems really high. Should I do more in manual ISO?

You do manual ISO wouldn't make a difference. You picture was exposed correctly just the ISO is high and it's noisy. If you lower your ISO you would get underexposed picture and when you brighten it up in post the noise come up with it.
So to fix the problem you must know that you really don't have to liberty to set your shutter speed and aperture any way you want and everything is still OK.

NikonRocks Loc: Sydney

Steve Carlson wrote:

90% of the time I shot in manual with auto ISO. I always take a test shot of subject, look at histogram and make adjustments with aperture and shutter speed. Yesterday in LR I was making adjustments to a photograph I stood in the middle of a cloudy day and noticed ISO was went to 2500. Seems really high. Should I do more in manual ISO?

You didn't mention what camera you were using. When I set my Nikon D7200 to Auto ISO I have limits available to me that I set in the menu system to stop ISO exceeding my predetermined value to avoid excessive noise. Currently I have it set to 8000. If I set shutter speed and aperture control to work in manual mode and the subject brightness called for ISO to exceed 8000, I would notice the exposure meter in the viewfinder to going negative indicating underexposure. At that point I could adjust either or both shutter speed and aperture to get the exposure correct with ISO staying at 8000 or get it lower by using a lower shutter speed and/or open up the lens if possible. The ISO value is always visible in my viewfinder so I have all three exposure variables at my fingertips so to speak.

scubadoc Loc: Sarasota, FL

The noise introduced by using auto-ISO is also influenced by sensor size. A full frame Sony/Nikon/Canon should produce less noise than a 1/2 inch sensor. The Inherent dynamic range of your camera will also have a bearing on noise. But noise present in a SOOC image is so easy to clean up with modern software, that it is becoming a non-issue, at least for me. It introduces one more step in the post process workflow, but if the image is worth it, depending on how you are going to display your final image, the additional step really doesn't require that much time or effort.

tcthome Loc: NJ

Depends on the pic taken. You would probably need a longer shutter speed to get a lower iso. If a vr lens or ibis can't get the shot (in focus) then a tripod & longer shutter speed would be needed (when I do this I usually switch to manuall iso). When I first tried auto iso I was surprised it went to 2500 also on a cloudy day in partial shade. You can reduce some of the noise with your post processing software but, you usually loose some detail. I haven't used these as of yet, But Topaz Denoise & the Nik software are supposed to be pretty good at this.