ISO Settings

Mlallous

Hey guys, so I was trying to adjust my ISO setting to be automatic since I'm a beginner, and my camera told me I can't adjust ISO settings because of the state of my camera? What does that mean?

bruto

You cannot adjust ISO at all if the camera is set to Automatic mode. In that mode, ISO is always automatic and there is no user input allowed. In the picture modes, you adjust ISO to manual or automatic using the ISO dial (or setting in [i] menu) only. The choices are all the usual ISO settings, plus Auto. If you set one of the manual settings, it will always shoot at that one, and if you set it at Auto, it will always be Auto with no user input.

The auto ISO settings in the menu apply only to A, S, P and M modes, and are not allowed in other modes. For those modes, the "Auto" setting on the ISO dial is grayed out. You set a starting ISO, and Auto ISO will modify that according to what the meter calls for. You can set a maximum to which it will go (sometimes you don't want it to go automatically to the very top), and a shutter speed below which it will switch.

If the D5100 manual is anything like the D3200 manual, the ISO issue is poorly explained. Your best bet in figuring out what does what and when is to try everything!

izivanovic

I am in the Aperture mode on my D5100 (manual as well fails), and I still can't put auto on. I know @Moose replied on this question a long time ago, but I lost the email.

bruto

You need to go to the menu. You can't get at it with the ISO dial or the [i] menu. You can not turn it off or on except in the shooting menu.

izivanovic

Oh I know, I am there in "ISO Sensitivity Settings" under A mode, but the setting is still grayed out when dialing towards it.

izivanovic

Nevermind, I'm an idiot. I didn't realize we were talking about the bottom part of the selection, so yes my Auto ISO is on, but I am having trouble setting the proper auto settings. Sensitivity was set to 200, but the MAX sensitivity and MIN shutter speed is fun to understand.

Moose

@izivanovic - Yeah, Auto ISO on Nikon DSLR's can be confusing. With regards to the max ISO and min shutter speed, generally speaking, I would set the max ISO to 6400 and the min shutter speed between 1/60-1/200. Choose a slower shutter speed when shooting motionless subjects and a faster shutter speed when photographing people and other "moving" subjects.

bruto

For minimum shutter speed, you might do well to experiment with the lenses you have. Different people have different abilities getting a sharp image at slower speeds. The minimum speeds setting ignores VR as well. It's too bad the implementation of auto ISO is so inconvenient, because it is nice to be able to override the safe shutter speeds when using the short end of the VR kit lens, or when using a tripod.

Some higher end cameras, such as the D7100, make this much easier. It's a menu setting you want to get used to finding in a hurry.

A general rule of thumb is that the minimum shutter speed without VR should be the reciprocal of the lens's full frame focal length. So, for example, if you have a 100 millimeter lens, your safe shutter speed on a DX camera should be 1/150 or faster.

If you can, you can do a little test for yourself, in a fairly dark indoor room that has a number of little LED lights, or for example the glowing display of a digital clock or video equipment. Round LED pilot lights are ideal. Put the camera on shutter priority or manual mode, and hand-shoot at those lights from a normal distance at different shutter speeds. Exposure is not terribly important here as long as the lights show. When you investigate close up, you'll readily see when a round light is elongated or oval. That's the speed at which you are getting camera blur with whatever lens you're testing. If you do this a number of times with the same lens, you'll likely get a percentage of good shots and bad, but you're going too slow if good ones don't predominate.

Slight camera blur can be subtle, and soften a picture without its being obvious what the problem is.