Auto ISO seems to be doing something funny on my D80

I went and shot a some pictures of the sunset, just to experiment with my new D80. I fiddled around with Matrix metering, which seemed to handle it decently.

But I tried out auto ISO for the first time, and it did some things that really surprised me. It jacked up ISO way higher than it needed to, and used a much higher shutter speed as a result.

Here's a couple of examples, among the pictures I liked best.



Focal Length 34 mm
Exposure Time 1/4000 sec
Aperture f/4.5
ISO Equivalent 500
Metering Mode matrix (5)
Exposure Program aperture priority (3)



Focal Length 150 mm
Exposure Time 1/4000 sec
Aperture f/5.6
ISO Equivalent 640
Metering Mode matrix (5)
Exposure Program aperture priority (3)

Shouldn't it have dropped the ISO down when it didn't need to be this high? I checked the manual and it didn't offer any explanation, and I've searched this forum and haven't found the answer.

I'd be very appreciative of any insight on this. Does anyone know what's up?

Thanks,

Bob

Sunsets are perfect for making bracket exposures. The sun is moving very slowly and film is cheap. Make manual settings and take several pictures, you will be glad when you start to look at them on the computer.

In defence of Matrix metering..... hmmm... the picture has a very bright object (the sun) and very dark areas (the sea). It's not easy to meter. I wouldn't expect the camera to know what to do. I wouldn't be too concerned about how it got confused- but on the other hand, if it was for example a portrait in normal light, then I think you should try to figure it out. Sunsets are pretty special and not often easy.

I always try to bracket wildly in the chance that I would get new ideas about the scene.

Guy Moscoso

You know, bracketing occured to me. That was what I was going to try next.

But this mission was about Auto ISO.

Do you know what's up with that? A lot of the pics I shot were cranked up to ISO 800. And then it shot them at 1/4,000. Why?

Thanks,

Bob

remember the old joke;

patient; "Doc, it hurts when I do this"

Doc; "Then don't do that"

moral of the story; don't use auto ISO.
--

Thanks for doing the test Bob on The Auto ISO performance. I will enjoy posting a "I told you so" message in the Nikon Metering Tips thread to a couple of the guys who told me I I had no idea on what I was talking about.

Cheers

Bob G-man said:

I went and shot a some pictures of the sunset, just to experiment
with my new D80. I fiddled around with Matrix metering, which
seemed to handle it decently.

But I tried out auto ISO for the first time, and it did some things
that really surprised me. It jacked up ISO way higher than it
needed to, and used a much higher shutter speed as a result.

Here's a couple of examples, among the pictures I liked best.



Focal Length 34 mm
Exposure Time 1/4000 sec
Aperture f/4.5
ISO Equivalent 500
Metering Mode matrix (5)
Exposure Program aperture priority (3)



Focal Length 150 mm
Exposure Time 1/4000 sec
Aperture f/5.6
ISO Equivalent 640
Metering Mode matrix (5)
Exposure Program aperture priority (3)

Shouldn't it have dropped the ISO down when it didn't need to be
this high? I checked the manual and it didn't offer any
explanation, and I've searched this forum and haven't found the
answer.

I'd be very appreciative of any insight on this. Does anyone know
what's up?

Thanks,

Bob

Click to expand...

--
http://www.flickr.com/photos/k-blad/

Bob could you please post some Auto ISO samples to illustrate the strange behavior

Bob G-man said:

I went and shot a some pictures of the sunset, just to experiment
with my new D80. I fiddled around with Matrix metering, which
seemed to handle it decently.

But I tried out auto ISO for the first time, and it did some things
that really surprised me. It jacked up ISO way higher than it
needed to, and used a much higher shutter speed as a result.

Here's a couple of examples, among the pictures I liked best.



Focal Length 34 mm
Exposure Time 1/4000 sec
Aperture f/4.5
ISO Equivalent 500
Metering Mode matrix (5)
Exposure Program aperture priority (3)



Focal Length 150 mm
Exposure Time 1/4000 sec
Aperture f/5.6
ISO Equivalent 640
Metering Mode matrix (5)
Exposure Program aperture priority (3)

Shouldn't it have dropped the ISO down when it didn't need to be
this high? I checked the manual and it didn't offer any
explanation, and I've searched this forum and haven't found the
answer.

I'd be very appreciative of any insight on this. Does anyone know
what's up?

Thanks,

Bob

Click to expand...

--
http://www.flickr.com/photos/k-blad/

That's why I never use auto ISO.

My motto is why shoot anything auto at all if you have time to set the camera (and by that I mean aperture, shutter speed and focus).
I hate P and A on cameras, they are mostly for dullards.
Jules

--
Black holes do not destroy information.

In contrast to many other users here, I indeed use auto ISO but I use it in low light situations. In your situation I would lock the cam on ISO200 and bracket.

When I was in Crete this summer, I woke up early 4 days to catch the sunrise. I took hundreds of pictures at all exposure settings and even white balance settings too. There was tons of time to figure it out. But did I need to learn how to get "THE perfect sunrise"? No. The next time I just have to figure out how to bracket quickly. Now my brain can go on to more fleeting photography.

When I use auto ISO i use spot metering on people's faces. A face needs to be exposed properly. Clothing is less important. Sunsets, flowers and buildings don't have to be correct in the same way. You can choose to under and over expose those other things because there is less a question of "Wasn't that a picture of Samantha? I can't see her face." or "she's white as a ghost!"

If sunsets are going to be your thing, then figure out what the auto iso/metering is doing here, but if not find your style of picture and use time to figure out how your cam meters on those kind of pics. The lighting for sunsets is simply too wild to trust "I'm only gonna take one picture and it HAS to be right" mentalility. Sunsets don't run away. You have minutes to figure out the exposure. People acting on stage and kids running around are more "capture the moment" situations. There, you have to know what your metering is doing.

If you need help with how to use auto ISO for low light stage photography, I'll gladly give you some tips.
Guy Moscoso

Auto ISO does have its place if it works properly and doesn't just crank the setting up to ISO 1600 every time.

Landscape or Macro photos are obviously not the right situation for it. Fast moving situations like journalistic type shots in low/variable light make Auto ISO very useful. The rider being that Auto ISO has to work properly in the first place. Better to get the shot than not get it
--
http://www.flickr.com/photos/k-blad/

Bob G-man said:

Shouldn't it have dropped the ISO down when it didn't need to be
this high? I checked the manual and it didn't offer any
explanation, and I've searched this forum and haven't found the
answer.

Click to expand...

It won't drop the ISO lower than what you've currently set it to on the Shooting Menu (ie. with the ISO button on the back). I'm still playing with the Min. Shutter Speed but I think this is a brilliant feature in A mode. It would be better still if it took the focal length into account. I haven't used it with Matrix though.

Stephan,

I think that what you mean by taking the focal length into account, you mean that with a 200mm lens you would want at least 1/200th sec which isn't on the auto iso menu, but actually just by using M mode you can choose shutter time of 1/200th sec and that is now the boundary before auto iso kicks in (or 1/300th etc..) so the boundaries are not limited to what there is on the menu. (at least for the D50)

Guy Moscoso

My first reaction was what the ….

Then I thought about it and have to ask what do you have your minimum shutter set for? I don’t think that my D70s can set the minimum shutter that high though the symptom sounds like minimum shutter set for 1/4000. If you minimum shutter is set lower than 1/4000 then there is something wrong with either your camera or the camera firmware.

Morris

--



http://qcpages.qc.cuny.edu/~morris/POD

Stephen Best said:

Bob G-man said:

Shouldn't it have dropped the ISO down when it didn't need to be
this high? I checked the manual and it didn't offer any
explanation, and I've searched this forum and haven't found the
answer.

Click to expand...

It won't drop the ISO lower than what you've currently set it to on
the Shooting Menu (ie. with the ISO button on the back). I'm still
playing with the Min. Shutter Speed but I think this is a brilliant
feature in A mode. It would be better still if it took the focal
length into account. I haven't used it with Matrix though.

Click to expand...

Actually, I think what's happening here is that the ISO is set to a high value and Auto ISO is trying to honour this, but can't because it's hit the limit at 1/4000. Hence it has to drop the ISO to bring it into range. If you set the ISO to 100 or 200 I think you'll get the results you expect.

gmosc said:

Stephan,
I think that what you mean by taking the focal length into account,
you mean that with a 200mm lens you would want at least 1/200th sec
which isn't on the auto iso menu, but actually just by using M mode
you can choose shutter time of 1/200th sec and that is now the
boundary before auto iso kicks in (or 1/300th etc..) so the
boundaries are not limited to what there is on the menu. (at least
for the D50)

Guy Moscoso

Click to expand...

That makes sense. I don't use lenses longer than 100mm though so it's not as critical. I'm still getting used to what I can get away with handheld with the D80.

"Dullards"

Someone who posts dullness without thinking whether or not anyone will benefit from reading said post.

JulesJ said:

That's why I never use auto ISO.
My motto is why shoot anything auto at all if you have time to set
the camera (and by that I mean aperture, shutter speed and focus).
I hate P and A on cameras, they are mostly for dullards.
Jules

--
Black holes do not destroy information.

Click to expand...

JulesJ said:

That's why I never use auto ISO.
My motto is why shoot anything auto at all if you have time to set
the camera (and by that I mean aperture, shutter speed and focus).
I hate P and A on cameras, they are mostly for dullards.
Jules

--
Black holes do not destroy information.

Click to expand...

Hmmm... I've recognized myself as a dullard for years. What's your point?

Judgements like these are not constructive on a forum that"dullards" frequent - to learn about their equipment.

Hi Morris,

My minumim shutter speed was set to 1/125 (the highest offered) and my maximum ISO was set to 800.

The funny thing is, I went back and looked at all the pictures I shot, and didn't find any pattern to what it was doing. I thought maybe it just kept raising the ISO, but didn't lower it, kind of like leaving it at the last setting, unless it needed to be raised. That could produce aberrations if you went from a dark scene to a bright scene. But no, that didn't happen.

ISO bounced all over the place, up and down, and shutter speeds were all substantially in excess of 1/125. In a series of almost identical pictures I went from ISO 280, 1/4000 - ISO 500, 1/4000 - ISO 800, 1/2000.

If it performed as you would hope, raising ISO the minimum amount, it would seem to be a nice tool. You would applaud Nikon for providing it. But it seems to bounce settings all over the place at least in my case.

I looked in the manual and found virtually nothing. The settings are explained, but the manual didn't even really say it would automatically keep ISO at the lowest possible setting.

I've submitted the question to Nikon's web support. I'll let you know what they say.

Thanks,

Bob

I keep it at that, and didn't tinker with it. I just checked and it's set to 200 now.

It bounced ISO all over the place, way up to 800 when it didn't need to. My shutter speeds were all much higher than the 1/125 setting I chose in the auto ISO menu.

Bob

Hi Brad,

I took your advice, managed to get my old D70 curve, sReala2, loaded into my D80, and I've been pretty happy with the results. It brightens the mid and low end of things without blowing out highlights at all. I've got a generally brighter, though lower contrast image, and I increase the contrast in post processing. I may blow highlights when I do that, but I get to decide whether and how much.

I still dial down EC some, but it isn't as critical and things don't vary so wildly.

It's proven better than using the contrast curves in the camera, trying to manage highlights, and then brightening the dark areas. More consistent. And I think brightening the dark areas generates some noise, at least in Nikon Capture.

So thanks. It's working for me.

Bob

Brad Morris said:

Thanks for doing the test Bob on The Auto ISO performance. I will
enjoy posting a "I told you so" message in the Nikon Metering Tips
thread to a couple of the guys who told me I I had no idea on what
I was talking about.

Cheers

Click to expand...

Hi Brad,

I'd be happy to.

I took a bunch of shots, but only pp'd a few. They were really only to test out the auto ISO, and not anything I was going to be too proud of otherwise.

Here's a sequence of 3, over a space of about 7 minutes. The settings change as follows:

ISO 200 1/500
ISO 800 1/2500
ISO 500 1/4000







(no pp at all)

What's it doing. I didn't even move my feet?

Maybe they haven't quite refined this feature yet. Maybe I got a bum camera. I'll post what I hear (read) from Nikon. I've emailed 'em.

Thanks,

Bob

Brad Morris said:

Bob could you please post some Auto ISO samples to illustrate the
strange behavior

Click to expand...