Martin Loc: Long Island NY

Do you use auto Iso or manual. I recently switched to auto ISO
since the camera is much smarter than me. Images are coming out much better.

hb3 Loc: Texas

Yes, I use auto ISO unless there is a specific reason not to...

LFingar Loc: Claverack, NY

Your aperture, exposure, and ISO all interact with each other. One of the first things you should learn about your camera is how they interact and how you can use them to get the photos you want. The basic concept is fairly easy. After that it is mainly a matter of practice to find out what works for you. "Understanding Exposure" by Petersen (I forget his first name) would be a good investment for anyone unsure of how it all fits together. There are also numerous on-line resources, many for free.

Cdouthitt Loc: Traverse City, MI

Yes and no...depends on the situation.

I shoot a lot in Aperture mode, so having the iso set to auto helps quite a bit. I have a max set a 3200.

Dlevon Loc: New Jersey

I'm an auto ISO user unless I've got specific requirements for the picture taking.

Cdouthitt Loc: Traverse City, MI

If I'm shooting in an environment with ample light, I'll set it myself, to the default or Low setting (if it is really bright).

DavidPine Loc: Fredericksburg, TX

Bryan Peterson.

:thumbup:

Db7423 Loc: Pittsburgh, PA

Manual all the way 99% of the time. Generally I would rather keep the ISO at 100 and if not on a tripod set the shutter speed where I need it and let the aperature float when setup speed is necessary like shooting sports. Really there is no one answer as it really depends on which of the legs of the triangle are most important to obtaining the photo but auto ISO would be my last alternative of the three. ;)

architect Loc: Chattanooga

Of the three components of correct exposure, aperture, shutter speed and ISO setting, the first two are for creative control. Aperture for depth of field and shutter speed for freezing/ blurring movement. Anyone who has ever shot with Kodachrome film will recognize the limitations that ISO (25 and 64 for Kodachrome) had on creative settings. So the ability to have flexibility in ISO settings is a big advantage.

I will set my Nikon D90 on ISO 200 whenever I know lighting, natural or supplementary, will be sufficient or if I am using a tripod. But for all other conditions I set my camera on Auto ISO with a max of 1600 and minimum shutter speed of 1/60 sec or so. That allows me to set my aperture and shutter speed to suit the subject.

Swamp Gator Loc: Coastal South Carolina

I always set the ISO manually.
ISO should be the first thing you set when you arrive at your shooting location. You determine the proper ISO based on the lighting conditions and subject matter. And you can obviously change it as those things change.

Even if you choose to use auto everything else, you really should be able to set the appropriate ISO.

Don't trust your camera to pick the proper ISO for you. Cameras can be all over the place with it, for instance choosing ISO 1600 in bright light which you would never select yourself.

LFingar Loc: Claverack, NY

Yeah, that's the guy! :D

architect Loc: Chattanooga

I can think of few situations where a camera would select ISO 1600 in bright light. Except a manual setting of F-32 and 1/400 sec, as might be selected for an insect macro. Auto ISO allows the photographer to select the desired aperture AND shutter speed for a particular subject, while getting the proper exposure.

Nightsky Loc: Augusta, GA USA

Having learned this in the 1960's I never really used the auto settings. My current camera (D800) does not have an 'auto' setting for ISO, You have to choose it just like in the days of film. Only then you were stuck with that ISO rating for the whole roll. ISO, f-Stop and shutter speed all interact to get you the correct exposure. If you think of everything in 'stops' it makes it easier. Going from ISO 100 to ISO 200 is the same as going from f16 to f11, or going from 1/250 sec to 1/125 sec. Just remember that your digital camera has intermediate settings. Full stops are f2, f2.8, f4, f5.6, f8, f11, f16, f22, f32. Notice that if you take every other number, they double as you go up (2,4,8,16,32 - and 2.8, 5.6, 11,22). These are you primary 'full' stops. Some cameras offer half stops in between, some have 1/3 stops.

Shutter speed has full 'stop' equivalents also. 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000. Changing one full 'stop' on your shutter speed is the same as changing a full f/stop on your aperture.

ISO is the same - prime ISO numbers are 100, 200, 400, 800, 1600, 3200, 6400 etc... each is double the former. So changing ISO from 100 to 200 is the same as changing from f/16 to f/11 or changing from 1/500 sec to 1/250.

So it comes down to what effect are you trying to achieve.

The lower the ISO number the less 'noise' in your image, and the further it can be enlarged without problems. Low numbers are for things that move slowly or not at all. Higher ISO numbers are generally used for freezing action or in low light situations.

Use a large aperture (f 2.8) to get a very small depth of field, if you want to produce bokeh - throw the background out of focus. Use a small aperture (f 16) for great depth of field for landscapes.

Use high shutter speeds to freeze action or low ones to show some blurring which can also show action.

If there is not enough light to use the aperture you need, you can lower the shutter speed or increase the ISO.

They all work together to give you the picture you want.

I imagine that the auto setting is convenient for fleeting moments when there isn't time to adjust your camera, but never having had the option with film I guess I don't miss it.

rook2c4 Loc: Philadelphia, PA USA

I prefer manually selecting ISO, but there are times when ISO set to auto is most practical, particularly in time-critical situations. It can be very frustrating to miss capturing a magic moment because you were too busy fumbling around with camera settings.

Swamp Gator Loc: Coastal South Carolina

There may be few situations but there are some.
I'll give you an example. Some time back I was shooting a small group of birds in bright lighting and I wanted the entire group in focus. I selected aperture priority and f16 and as an experiment I also choose auto ISO.

The camera selected a high shutter speed (which I didn't need)
And it also selected an ISO of 1600 to get me those settings (which I certainly didn't need)

I would have gotten a much better picture selecting all three on my own and that's exactly what I did once I realized what the camera had done to me.

My point is that for those that tend to use a lot of auto settings just be aware of what the camera might do because the camera doesn't *know* what you want.
It essentially makes an educated guess based on the lighting conditions and what if any settings you have already selected.

And for anyone that is knowledgeable enough to select the proper shutter speed and lens opening depending on the lighting and subject mater, they also should be able to competently select an appropriate ISO.