How bad is it to use Auto ISO?

If I cant take a good shot at ISO100 then I don't bother. For long exposures, and tripod use I keep it at ISO100 and rarely use 200 or 400. But, on a trip to NV I was forced to use ISO800 in low light outdoors.

Gomar wrote in post #17675779
If I cant take a good shot at ISO100 then I don't bother. For long exposures, and tripod use I keep it at ISO100 and rarely use 200 or 400. But, on a trip to NV I was forced to use ISO800 in low light outdoors.

Were you formerly a color slide shooter?

Gomar wrote in post #17675779
If I cant take a good shot at ISO100 then I don't bother. For long exposures, and tripod use I keep it at ISO100 and rarely use 200 or 400. But, on a trip to NV I was forced to use ISO800 in low light outdoors.

Why...?

I really don't get that mindset, I've heard it before and it baffles me every time.

So here is a photo from the whale watching. This one and some others are linked to the wildlife forum here.

IMAGE LINK: https://flic.kr/p/xNkc​5q

Using Auto ISO is inherent no worse than using another automated setting by the camera, like Av or Tv. What makes Auto ISO 'worse' is simply the incompleteness of the implementation, based upon camera model...the oldest Auto ISO cameras had attrocious implementations that might stupidly choose ISO 1600 1/4000 rather than selecting a more appropriate ISO 400 1/1000. The newest models have far better Auto ISO capabilities than the 10 year old ones! Are they good enough?...it depends upon one's expectations and needs.

Any automation has the flaw of the meter being fooled by subject brightness issues...and EC is the typical means of 'being smarter than the meter'. That applies to any of the automated settings. At times, what makes the most sense for a situation is M with user-set ISO, because the light falling upon the scene is NOT perpetually changing...only the subjects running in and out of the frame are altering the reflected light -- but not the illumination falling on the scene!

rrblint wrote in post #17672330
On the 550D and other Rebel cameras it is impossible to bias the meter in M with Auto-ISO set. It will always be centered unless the ISO bottoms or tops out.

My 70d is the same way - no exposure bias in manual mode. I'm told it will be an option with magic lantern.

Back to the OP, I have a similar circumstance when shooting my daughter's soccer games. I need a certain shutter speed (1/250, IIRC, gives a touch of motion blur in the middle of a kick). I'd also like to stop down little for more forgiving focusing, but I can't shoot in manual if I want to boost the exposure 1/3 or 2/3 of a stop. As I practice more, I might work around my camera's limitations by narrowing the metering mode for proper exposure of the target without unduly being influence by the sky, and then shoot in manual mode.

But full manual doesn't work for me with fast action - as you've already pointed out, its too dynamic a situation.

And when I refer to my camera's limitations I mean my limitations.

iowajim wrote in post #17688658
My 70d is the same way - no exposure bias in manual mode. I'm told it will be an option with magic lantern.

Back to the OP, I have a similar circumstance when shooting my daughter's soccer games. I need a certain shutter speed (1/250, IIRC, gives a touch of motion blur in the middle of a kick). I'd also like to stop down little for more forgiving focusing, but I can't shoot in manual if I want to boost the exposure 1/3 or 2/3 of a stop. As I practice more, I might work around my camera's limitations by narrowing the metering mode for proper exposure of the target without unduly being influence by the sky, and then shoot in manual mode.

But full manual doesn't work for me with fast action - as you've already pointed out, its too dynamic a situation.

And when I refer to my camera's limitations I mean my limitations.

With M mode, you inherently can do what the EC does (for automation modes Av and Tv) simply by not aligning the 'needle' to be centered on the scale in the viewfinder!!!

As for 'too dynamic a situation'... if the sun is out and there are no clouds in the sky, or if the sun it always behind overcast sky, the LIGHT IS NOT CHANGING. You meter indicates when a white jersey or a black jersey runs in/out of the frame, but the LIGHT IS NOT CHANGING, so there is absolutely ZERO need to alter exposure. Just because a black jersey reflects less light to the in-camera meter, and a white jersey reflects more light to the in-camera meter, does NOT mean that light falling upon the scene (and the necessary exposure setting) is changing, too.

Mr_ipsum wrote in post #17682812
So here is a photo from the whale watching. ...
I started off using Tv with the auto ISO, but it consistently underexposed the photos. So I quickly switched to Av and set the ISO to about 100-250. Even though it was cloudy outside I was able to get a much higher shutter speed then I anticipated. Maybe I was just over thinking everything.

Mr. Ipsum could easily have used M mode for his whale watching shooting...it the clouds were unbroken overhead, the light falling upon the scene was not changing...only the amount of sky vs. water was changing (affecting the reflected light), but not the amount of illumination (not affecting the incident light).

If the sun is playing hide and seek constantly due to broken cloud cover, THEN the light IS changing, and an automated mode (Av or Tv or Auto ISO) can be handy for keeping up with the perpetual changes in light which falls onto the scene.

Wilt wrote in post #17688704
With M mode, you inherently can do what the EC does (for automation modes Av and Tv) simply by not aligning the 'needle' to be centered on the scale in the viewfinder!!!

The challenge is to figure out how to do that when in auto ISO.

Archibald wrote in post #17688709
The challenge is to figure out how to do that when in auto ISO.

Which is a very valid reason to never use Auto ISO -- until the camera body that you have supports an EC control for Auto ISO

Archibald wrote in post #17675786
Were you formerly a color slide shooter?

I was, sometimes 70 rolls a day, and...

Archibald wrote in post #17688709
The challenge is to figure out how to do that when in auto ISO.

...we got along just fine without "Auto" anything, except the motor drive, of course.
Take a step into the past! It really isn't all that difficult. ; )

Wilt wrote in post #17688711
Which is a very valid reason to never use Auto ISO -- until the camera body that you have supports an EC control for Auto ISO

With my Rebel SL1, I can get kludgy exposure compensation by auto-bracketing. So I have to take 3 shots to get one exposure that is as desired. At least the wasted two shots don't cost anything.

PhotosGuy wrote in post #17688715
I was, sometimes 70 rolls a day, and...
...we got along just fine without "Auto" anything, except the motor drive, of course.
Take a step into the past! It really isn't all that difficult. ; )

I still have my Pentax Spotmatic F and Hasselblad 500 C/M at the ready.

That old legendary gear - absolutely fantastic, and never equalled!!...

Or so I thought. As time goes on, I keep dashing the old legends. The Takumar SMCs that we bowed down to are crap compared to today's cheap zooms. Film resolution is poor compared to sensors even in cheap Rebels. More recently I found that even my expensive Leica ball head that I owned and worshipped for 40 years is really quite bad compared to a modern ball head.

If only my mind improved with age as photo technology does.

Archibald wrote in post #17688736
If only my mind improved with age as photo technology does.

Fat chance! ; D

"Getting old ain't for sissies!"
-- Bette Davis

Archibald wrote in post #17688717
With my Rebel SL1, I can get kludgy exposure compensation by auto-bracketing. So I have to take 3 shots to get one exposure that is as desired. At least the wasted two shots don't cost anything.

...except more wear and tear on the shutter assembly and reflex mirror assembly.

Archibald wrote in post #17688736
If only my mind improved with age as photo technology does.

You need a more positive mental attitude, "My mind today makes far more sound decisions than it did when I was 20!"

PhotosGuy wrote in post #17688715
I was, sometimes 70 rolls a day, and...
...we got along just fine without "Auto" anything, except the motor drive, of course.
Take a step into the past! It really isn't all that difficult. ; )

You could say the same exact thing about auto focus, in camera metering, etc. It doesn't mean everyone should or shouldn't use it. Learn to use the tools at your disposal, auto ISO is an amazing tool and I personally think you're only holding yourself back by not embracing the tech.

This coming from someone who still genuinely prefers manual focus lenses over auto focus, so again, everyone's needs and desires are different. I just think it's flat out silly to in any way belittle auto-ISO... it can be incredibly useful if you know how to use it properly (and if the manufacturer supports full usage of it, as in EC for M mode with auto ISO).