Question regarding Aperture Priority

steve_

I recently got a 5d mark 3 and when im out and about i tend to use aperture priority to take most photos but one thing im noticing is that the camera is shooting with a very high iso. For example, if im shooting in daylight at f4 the camera is using a shutter speed of 1/8000 and an iso of 12500 which just seems crazy to me. I cant crop as aggressively as id like due to noise but it seems like the camera is choose settings that are a bit too extreme.

Professey Chin

There should be a setting for the max ISO it can use. Ive it set to 800 on my D90 for most situations

Paulw

RTFM would be the first thing that comes to mind.

Have you set the ISO, or have you it on auto-ISO?
You can also set the max/min shutter speed, and also set the max-min ISO. These are in the custom functions.

Want to post a pict, and include the full EXIF so that we can see what you have set in the camera?

dirtyghettokid

choose your own ISO settings instead of leaving it on auto-iso

Tokyo

I guess I too find it strange that you have a top of the line full frame camera, but don't read the manual to figure it out. I took a quick read of it here:
http://gdlp01.c-wss.com/gds/8/0300007348/02/eos5dmkiii-im2-c-en.pdf

As others have mentioned, Auto ISO is switched on, which isn't necessarily a bad thing - I've heard rave reviews about the Auto ISO functionality of the mark III. If you look at the LCD screen, you'll see an "A" where the ISO speed should be.

To turn it off:

Press the ISO button (lightning bolt with +/- symbol)
Set the ISO to whatever you want, as long as it's not "A"

Alternatively, and I would recommend this, rather than disabling it completely, tailor it to what you want. By default, it runs from ISO 100 to ISO 12,800, but you can change the upper level down to something more acceptable to you.

In the camera settings menu:
Select "ISO SPEED SETTINGS"
Select "ISO SPEED RANGE"
Set the maximum limit.

steve_

Cheers Guys i capped it at 6400 for AV mode. I have read through the manual alright but didnt have it on me at the time so i couldn't remember how to change it

AnCatDubh

somewhat related (albeit, with no specific knowledge of the Canon) -

don't the camera engineers/makers opt for lower ISO by choice if it is available to them given a set of lighting conditions as it would naturally produce a cleaner image (i'm making this as an assumption rather than as a result of direct conversation with any camera engineer/maker). At lower ISO you need more light (wider aperture or slower shutter speed).

Soooooooo, at f/4 (quite a bit of light coming through) you'd expect the selected ISO to be lower unless you've mistakenly told it to shoot at the higher ISO or constrained the camera with either of the other shooting parameters - aperture, or shutter speed...

I tend to try not to allow the camera select the ISO but the 5D Mk III would have way better ISO performance than my dSLR so perhaps its not such an issue for you.

steve_

well initially this was my concern exactly. I couldn't understand why the camera wanted to shoot so fast with 1/8000 shutter speed which naturally forced the camera to bump up the ISO to very high levels. Just from a consumer stand point i would have assumed that when using AV mode the camera would select a happy medium between both shutter speed and ISO so that neither are very high yet still allowing for correct exposure. But the opposite appears to be true seeing as its using each extreme of the respective settings unless you manually tell it not to

dirtyghettokid

the very first thing i did when i bought my 5dmkII was take the ISO off auto. i shoot in aperture priority mode most of the time, so always manually adjust the aperture and ISO to what i want. i thought most people did that. might stick my 5d onto auto ISO for the craic and see what it does..

Tokyo

AnCatDubh wrote: »

somewhat related (albeit, with no specific knowledge of the Canon) -

don't the camera engineers/makers opt for lower ISO by choice if it is available to them given a set of lighting conditions as it would naturally produce a cleaner image (i'm making this as an assumption rather than as a result of direct conversation with any camera engineer/maker). At lower ISO you need more light (wider aperture or slower shutter speed).

Soooooooo, at f/4 (quite a bit of light coming through) you'd expect the selected ISO to be lower unless you've mistakenly told it to shoot at the higher ISO or constrained the camera with either of the other shooting parameters - aperture, or shutter speed...

I tend to try not to allow the camera select the ISO but the 5D Mk III would have way better ISO performance than my dSLR so perhaps its not such an issue for you.

From what I gather, 12,500 ISO shouldn't be a problem for the Mark III's sensor in terms of degradation. I don't own one myself, I have a Nikon D7000 at the moment which has a very similar setup, and while up until now I'd always set the ISO manually, I"ve started, on recommendation of some Nikon professionals, started toying with letting the camera take care of the ISO, with excellent results.

A quick read of the Canon 5D manual would indicate that with the Auto ISO feature. it also has a "Minimum Shutter Speed" setting that goes hand in hand with it. This may be throwing off the ISO settings in auto mode.

Promac

There's nothing wrong with the auto-iso on the 5d mark ii. Unless it's playing up in weird lighting conditions I have it on all the time.

Assuming the mark iii is similar or better you shouldn't really be seeing what you're seeing. Unless it was actually on manual or something.

pullandbang

Funny enough I noticed for the first time yesterday that when using the live view mode (5dMkII) to compose shots, the ISO seemed to switch to Auto and was hovering around 6400 - we were in very dark places.
Yet when I switched off live view to take the shot, the ISO popped back down to whatever I had it set at. Maybe it's a feature of live view but I never noticed it happening before.

Reoil

Or learn to shoot manually! Invaluable skill to learn.

pixbyjohn

steve_ wrote: »

I recently got a 5d mark 3 and when im out and about i tend to use aperture priority to take most photos but one thing im noticing is that the camera is shooting with a very high iso. For example, if im shooting in daylight at f4 the camera is using a shutter speed of 1/8000 and an iso of 12500 which just seems crazy to me. I cant crop as aggressively as id like due to noise but it seems like the camera is choose settings that are a bit too extreme.

At ISO 12,500 I wouldn't have thought the Mk3 would show any noise:mad:

homerun_homer

Op could you post some examples? I'm curious to know what lighting conditions you've shot in that the camera is choosing such high settings.

Tokyo

pullandbang wrote: »

Funny enough I noticed for the first time yesterday that when using the live view mode (5dMkII) to compose shots, the ISO seemed to switch to Auto and was hovering around 6400 - we were in very dark places.
Yet when I switched off live view to take the shot, the ISO popped back down to whatever I had it set at. Maybe it's a feature of live view but I never noticed it happening before.

I took a quick look online for this as I thought that I'd come across it before, turns out that it was a problem feature on the Mark II that has apparently carried over to the Mark III...

"Problem is if you have Live view set to stills + movie. In still only mode, you can change ISO in aperture priority, but in stills + movie it defaults to auto ISO. I don't think this is mentioned in the manual."

In other words, even in manual mode, if your Live View is set to "stills + movie," your manual ISO setting will be overridden by Auto ISO. Change your settings to Stills Only, and your chosen ISO setting will stick.

Ballyman

pixbyjohn wrote: »

At ISO 12,500 I wouldn't have thought the Mk3 would show any noise:mad:

Not being pedantic or anything but it's actually 12,800

There is noticeable noise though at this ISO on the 5D Mkiii as you would expect, although I would say it's similar to ISO1600 on my old 1dmkiii or ISO800 on the 40D and perfectly useable.