Auto ISO question

[Butterfly123]

I have a new Nikon D3100, and I have a question about the auto ISO setting.

I am currently learning to use the camera in the Manual mode. When I've need to take pictures more quickly, I've used the Program mode, so that I can control the ISO, among other things. I've noticed in some of the few pictures I've taken on Auto, that when the flash goes, and the front of the picture is lighter, and the background is darker, the camera bumps the ISO up to 3200, and the picture has some noise. Up to now, I've had the auto ISO set to off.

Here is the question: if i turn the auto ISO on, and set it to, say, 800, will that cap the ISO level in the Auto setting? Or does it just potentially override the ISO setting I select when in the other program modes? I can't figure out from the manual if there is ever a way to cap the ISO in Auto. I do know the scene selection settings in Auto do influence the ISO.

Sorry if I haven't explained this well. So far the worst pictures I've taken were in the Auto setting. And the reason I bought a DSLR is to learn how to shoot in Manual. I just want to understand how this Auto ISO feature works, and what happens when I turn it on! I'm guessing nothing will change how the camera sets the ISO in full Auto mode.

 

[HPS3]

I have the D5100 and tried the auto ISO in AP and TV mode. I have set my ISO to the function button on the front left side of the camera and control it myself. I hated taking a picture and having to turn off auto ISP just to get the settings I want. With the ISO assigned to the function button it's easy to adjust, just hold the button and turn the dial.

 

[Marlton Mom]

I have a Nikon D90 which is a different model of camera so I can't really give you specific answers to your question since I don't have your model of camera to look at and see what is included in the Menu options and what is missing when compared to the D90.

What I can do is suggest that you google this question and see if it has come up in any threads on the web about your specific model. I know Flickr has a D90 section where Auto ISO questions have been asked and answered. That's where I had my questions answered about auto ISO.

Auto ISO is a sticky wicket and if you have it set in the menu then you have to understand how that will affect other settings so be careful. On the D90, having Auto ISO on will overide ISO manual adjustments in M,A,S,P modes so you will start to think something is up with your camera when you can't adjust ISO because you have forgotten and left it selected to on.

The way that Auto ISO is best used (according to what I've read) is that you use it in Manual mode with a locked shutter and Aperture settings. The range (this setting is available on the D90, I don't know about the 3100) that you set for Auto ISO is what the camera uses as a variable when metering the shots.... so to recap, the shutter is fixed, aperture is fixed and say you are tracking a moving subject like kids at a soccer game, then if they run into the shade, the camera will be able to adjust based upon the ISO range that I set in my D90. Just remember to turn it off in the menu settings when you are done needing that option.

I commend you for wishing to go further in your understanding of your camera. It can be a very frustrating process of discovery and understanding, but once you put those 'tools of understanding' in your knowledge base your creative options and abilities will will grow exponentially! That tip about googling things that the manual does a crappy job of explaining has been gold for me. I hope it helps you too!

~Marlton Mom

 

[wbeem]

Any auto mode will let the camera decide how and what to expose, not you. There's more to the issue going on with the pop-up flash, too. It may be corrected by switching to rear-curtain sync.

The difference with rear curtain sync is that the flash fires at the end of the exposure, instead of the beginning. That could be why you're seeing that dark background. You need to let the ambient light fill in more of the exposure, and then freeze your subject with the flash. I do this with the SB-800 or SB-900, but haven't tried it with a pop-up flash.

I'm having a hard time understanding why you need auto ISO to react quickly. Are your lighting levels changing drastically?

 

[My2Girls66]

You can cap how high you want to iso to go. It is in the menu for auto iso. I tend to keep my D80 on auto iso(usually set at 800 max) because I tend to not remember to change it myself when needed. I just have to remember to shut it off when taking night shots with a tripod. I took some pretty noisy fireworks photos at Disney a few years ago because I forgot to set it back to 100

 

[Butterfly123]

Thanks everyone for your replies. Wbeem...I see your confusion in the way I worded my question...sorry! What I meant was that I wanted to take pictures more quickly than I am able to take them in Manual...because it takes me a while to think through my settings at this point. I put it in Program mode, because the camera would choose the settings, and I could fire off shots more quickly. I have had much better success with my pictures in Program mode choosing the ISO myself, than with Auto mode.

So what I am gathering is that auto ISO effects the P, A, S, and M settings, in that it can override my ISO choice, but that it does nothing to effect the ISO in the Auto mode.

Marlton Mom...thanks for your encouraging words!

 

[wbeem]

OK, I understand that the modes make things go faster because you don't have to think about something and change a setting. The question that comes to mind for me is this - are you happy with the results you're getting from Auto ISO & P mode? If not, is it really worth being faster?

One of the reasons people end up changing their camera to a higher end model is because of the controls that are available to quickly change settings. My D700 has buttons that allow me to switch ISO, White Balance, Aperture & Shutter speed on the fly without having to go into any menus.

If you don't have those buttons and it's cumbersome to change your settings, it may seem better to use an auto mode of some kind. After a while, I think you'll get to the point where you know what you want (because the auto settings don't really know) and you'll just want a faster way to make your own manual changes.

A good example of this would be something like the WedWay PeopleMover. Bright light outside, then you go in Space Mountain, then back in bright light, then into Carousel of Progress, etc. I was flipping my ISO back & forth all the time to take shots. Never once considered auto ISO. If I had a camera that made ISO changes more menu driven, it may have seemed desirable, though.

 

[Butterfly123]

You are right...what I want is control. I am really pleased that I am having so much fun learning how to use my camera. The D3100 does have a button to access ISO settings without having to go into the menu. I just need to spend more time shooting, so I can get faster at knowing the settings I want.

Thanks for everyones help. I really do want to understand the settings available, even if I don't use them all. I did google Auto ISO with the D3100, and it does sound like people did have an issue with the ISO bumping up really high at times when shooting in Auto mode. I guess that's another good reason to stay out of Auto, especially if there is no way to control that with the Auto ISO setting.

 

[My2Girls66]

You are right...what I want is control. I am really pleased that I am having so much fun learning how to use my camera. The D3100 does have a button to access ISO settings without having to go into the menu. I just need to spend more time shooting, so I can get faster at knowing the settings I want.

Thanks for everyones help. I really do want to understand the settings available, even if I don't use them all. I did google Auto ISO with the D3100, and it does sound like people did have an issue with the ISO bumping up really high at times when shooting in Auto mode. I guess that's another good reason to stay out of Auto, especially if there is no way to control that with the Auto ISO setting.

I find 'P' mode is much better than 'Auto' on both my D80 & D50. Full auto chooses the focus point and pops the flash up when you might not want it, both are quite annoying to me. I find with my cameras that the ISO(in auto iso mode) will stay at 100 or 200 unless I am shooting in shade or when its getting dark out then it boosts it as needed.