I recently purchased a refurbished D5100 and noticed that in AUTO mode, many, if not all of the pictures I take, are very grainy, then I noticed that the camera sets the ASA to 3200. Almost every flash picture I take the camera sets ASA to 3200. In P, S or A modes, the ASA numbers are set to a reasonable number, 200 or 400 or whatever ASA maximum number I set it for.

Is this the way the AUTO mode is supposed to work for the 5100, or do I have a defective camera? I have been searching on the web to see if other 5100 users have the same problem, but never found anyone having this problem.

I've used many Nikon digital cameras since 1999 from a coolpix 950, 4500, 8800 & D60 and non of those had a similar problem in AUTO mode.

Fran

Visit my Nikonians gallery.

I guess I'm still using ASA for film speed, but I assume ASA is the same as ISO, is that correct?

Visit my Nikonians gallery.

You are correct, ASA and ISO values are identical. However, and almost without exception, all reviews, user's manuals, articles and written material use the term ISO rather than ASA. As such, it is probably worth abandoning the old designation.

The information that you have provided is not enough to give you a definitive answer to your original post, however, almost all of the newer DX cameras will default to the highest ISO that you set in the Auto-ISO menu when you are using the built in flash in low light conditions. It is not a defect, but rather, it is by design. I also find it objectionable and originally thought that it was a firmware flaw. So, if you want a lower ISO value with the flash, you have to turn AUTO-ISO off or limit the top value.

I never use "AUTO" so I can't comment on behavior in that mode. EDITED TO ADD. However, I can tell you that AUTO mode lets the camera select all settings including when it thinks that you should use the built-in flash. Since you obviously use the AUTO-ISO menu settings, as do I, you might be better off to use P (Program) to keep the flash from firing when it is really not needed since you are using high ISO values. Most photos with the built-in flash are somewhat "harsh" in low light.

jP

As JP suggests, using the Green-AUTO (or any of the scene modes) will by default place you into certain settings. Some of those settings can be over-ridden while some cannot.

Looking at the D5100 Reference Manual it appears that the Green-AUTO mode puts you into Auto-ISO with no ability to change it. So as JP suggest you may need to lower the maximum ISO setting for Auto-ISO to possibly prevent that from happening; or don’t use Green-AUTO mode when faced with such situations.

Pete

Visit my Nikonians gallery.

I remember ASA from when Kodachrome had an ASA of 10. ISO means something else in the computer world.

I spent last summer shooting my D5100 in some incredible places. I had to learn the camera quickly before the trip. I shot both video and stills at the same venues. I found that shooting in Aperture mode was the most productive. If you shoot video, I think you have to shoot in Aperture mode.

I remember adjusting the Aperture with the command dial, and the ISO by pressing the Fn button on the left side (After setting the Fn button to control ISO) and then adjusting ISO with the command dial while making sure that the shutter speed was in the proper range. It is a little cumbersome, but it was the best I could do. The controls on the D5100 are a little different than what I was used to on other Nikon DSLRs. I found that neither eagles nor bears liked the sound of the D5100 shutter.

Hope this helps.

Charlie

Visit my Nikonians gallery.

If you would like a technical explanation of the evolution, similarities and differences, here is a link:


http://en.wikipedia.org/wiki/Film_speed

On my D3100 this is how it works, and I think your 5100 is very similar:

If you are using flash, and have the ISO mode set to "auto ISO" every single time you use flash, it will set the ISO to 3200. You want to go to "ISO sensitivity" on the shooting menu, and set "auto ISO sensitivity" to OFF. I don't know why it does this, but others have verified this for me a few months ago.

With the "auto ISO" on, it will set the ISO up to your specified max, to hold the shutter speed up to whatever shutter speed you select as the minimum desired speed. This can be very useful, if you are in changing light conditions, as long as you don't use the flash.

If you have the mode on the big dial set to auto, the camera will select varying ISO settings depending on the subject, even if you are using flash. If the complete auto mode is set, you cannot modify the ISO setting. It will not always be 3200, but it could be. I just made a couple of test shots to verify this. One of them was at 2500, the other at 2800, in a moderately dim room with the flash automatically popped up.

Hope this helps.

working on it in Middle TN
Nikon D3100
18-55 mm Nikkor VR
55-200 mm Nikkor VR
55-300 mm Nikkor VR
150-500 mm Sigma OS

Visit my Nikonians gallery.

>If you are using flash, and have the ISO mode set to "auto ISO" every single time you use flash, it will set the ISO to 3200.

Diane

That is not entirely correct. The camera will only select your highest ISO if the meter reading without the flash would have called for that ISO. In other words, it only occurs in low light situations. To demonstrate, set your top AUTO-ISO to 3200 or 6400 and then go outside in bright daylight and take a flash picture, basically a fill-flash picture. Notice that the ISO for that shot is not 3200 or 6400, but rather closer to your preferred setting of 100 or 200.

I haven't verified this since I rarely use the built-in flash, and if I do I turn off Auto-ISO, but I read an explanation that I believe stated that the camera reduces flash output rather than lowering the ISO. Personally, I don't like this firmware decision, but turning off AUTO-ISO or limiting the top setting is an easy workaround.

jP

>>If you are using flash, and have the ISO mode set to
>"auto ISO" every single time you use flash, it will
>set the ISO to 3200.
>
>Diane
>
>That is not entirely correct. The camera will only select
>your highest ISO if the meter reading without the flash would
>have called for that ISO. In other words, it only occurs in
>low light situations. To demonstrate, set your top AUTO-ISO
>to 3200 or 6400 and then go outside in bright daylight and
>take a flash picture, basically a fill-flash picture. Notice
>that the ISO for that shot is not 3200 or 6400, but rather
>closer to your preferred setting of 100 or 200.
>
>I haven't verified this since I rarely use the built-in flash,
>and if I do I turn off Auto-ISO, but I read an explanation
>that I believe stated that the camera reduces flash output
>rather than lowering the ISO. Personally, I don't like this
>firmware decision, but turning off AUTO-ISO or limiting the
>top setting is an easy workaround.
>
>jP

OK I've never tested this using the built-in flash outside, with moderately bright or bright light. You are quite likely right.

I assumed the OP was talking about using the flash indoors, with fairly low lighting.

working on it in Middle TN
Nikon D3100
18-55 mm Nikkor VR
55-200 mm Nikkor VR
55-300 mm Nikkor VR
150-500 mm Sigma OS

Visit my Nikonians gallery.

I just tested my D3000. With ISO set to Auto in the menus, the default maximum ISO setting is 1600. With Mode Dial set to Auto, I took a picture inside. ISO was 200. When I switch back to Aperture Preferred, ISO is controlled from the Fn button and Command Dial.

Laverne

The Auto-ISO in the menu functions to keep the shutter speed where you want it. In the menu where you set the Auto-ISO, below it, there is a place to set a minimum shutter speed you wish to maintain. So the Auto-ISO will change to maintain that.

The exception is if you use the buit-in flash indoors, in which case the auto-ISO always goes to 3200.

This is on my 1-yr old D3100. The auto-ISO behavior may be different in other models.

working on it in Middle TN
Nikon D3100
18-55 mm Nikkor VR
55-200 mm Nikkor VR
55-300 mm Nikkor VR
150-500 mm Sigma OS

Visit my Nikonians gallery.

>
>The exception is if you use the buit-in flash indoors, in
>which case the auto-ISO always goes to 3200.
>
>This is on my 1-yr old D3100. The auto-ISO behavior may be
>different in other models.

Hi Diane,

The D3200 with auto ISO set to a high of 3200, even with flash indoors, the ISO can go below 3200. It all depends on the level of ambient light.

I just took an indoor photo with and without flash. The room was not bright but not dark either. Without flash Auto ISO set ISO to 2500. With flash it set ISO to 2000 using aperture priority set to f5.6. If I set the lens to f1.8 the ISO went down to 400. In my darker den I took another flash photo where auto ISO set it to 3200 at f5.6. At f1.8 it dropped to ISO 1400.

Auto ISO can be a valuable tool for pros and amateurs alike. But I would advise everyone to learn how it works. For those that want to learn how their camera works I would advise to not use auto everything.

edit: The D5100 works the same way as the D3200.

Len

Visit my Nikonians gallery.

Most of the recomendations I see from the serious flash users are to set Auto ISO off when using the flash.

Visit
My Nikonians Gallery
NorcrossPics.Com

Visit my Nikonians gallery.

>Most of the recomendations I see from the serious flash users
>are to set Auto ISO off when using the flash.

The only time I ever use Auto ISO is when I'm answering a post where there is a question about auto ISO. I don't like it and won't use it, flash or not. I like to control everything.

Len

Visit my Nikonians gallery.

A lot of people feel that way. I use Auto ISO when the light is changing, mostly sports late in the evening as it goes from light to dark. It helps to get the max shutter speed.

Visit
My Nikonians Gallery
NorcrossPics.Com

Visit my Nikonians gallery.