# Tutorial on Auto ISO



## RGF (Mar 24, 2013)

I have tried auto ISO but have yet to get the hang of it. Is there a good tutorial on it?

Ideally I would like to set a minimum shutterspeed, aperature and maximum ISO. If the exposure could not happen, then I would like to specify which would be sacrificed. Gets complicated very quickly.


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## Mt Spokane Photography (Mar 24, 2013)

The ability to do this depends on the model of camera.
With a 5D MK III or the 1 Series bodies, you can do it.

The others have severe limitations.

Which body are you using?


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## bdunbar79 (Mar 24, 2013)

Mt Spokane Photography said:


> The ability to do this depends on the model of camera.
> With a 5D MK III or the 1 Series bodies, you can do it.
> 
> The others have severe limitations.
> ...



Yeah, kinda need the model you're using. The 1D series have many more capabilities with auto ISO than lower models, so what model are you using?


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## Rienzphotoz (Mar 24, 2013)

bdunbar79 said:


> Mt Spokane Photography said:
> 
> 
> > The ability to do this depends on the model of camera.
> ...


Mt Spokane Photography & bdunbar, 
What do you mean, when you say the others have limitations or the model/body makes a difference ... can you please elaborate ... I mean, when I used to shoot with 7D & 60D on Auto ISO, the camera would choose pretty much the same ISO for 2 different shots of a same image in identical light setting ... so what is it that extra which my 5D MK III can do in auto ISO that another camera, (say, a 60D or a rebel) cannot do?

Thanks in advance


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## Spooky (Mar 24, 2013)

The auto ISO menus allow differing setups depending on the model, which RGF has not mentioned.
If my memory serves me correctly, my 7d does not allow minimum shutter speeds, only max ISO, unlike my 5d which allows more customisation.


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## neuroanatomist (Mar 24, 2013)

The 5DIII let's you pick a minimum shutter speed in Av mode up to 1/250 s, in addition to specifying a range for Auto ISO (the 60D and 7D with v2 firmware, but not v1, can set a max for Auto ISO but not a min, and no min shutter).

The 1-series bodies let you specify a range (max and min) for aperture, shutter speed (not limited to 1/250 s), and ISO that can apy to any mode.


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## Rienzphotoz (Mar 24, 2013)

neuroanatomist said:


> The 5DIII let's you pick a minimum shutter speed in Av mode up to 1/250 s, in addition to specifying a range for Auto ISO (the 60D and 7D with v2 firmware, but not v1, can set a max for Auto ISO but not a min, and no min shutter).
> 
> The 1-series bodies let you specify a range (max and min) for aperture, shutter speed (not limited to 1/250 s), and ISO that can apy to any mode.


Thanks, I think I understand ... hopefully :-[
Sorry for this stupid question but I'm not getting how that is useful ... I mean I if I need to choose slow/fast shutter speeds I generally use the Tv mode (or Manual mode if I also need a certain aperture), so what practical use do I have by limiting a particular shutter speed range by going to 'Menu', 'second Red shooting tab' and selecting the ‘Min. shutter spd’ etc? isn't that kind of a long winded way of doing things? 
How and when do you generally use this function? (I just saw that in my 5D MK III it is set to Auto ... I'm assuming that must be the default setting)
By the way my question is not meant to belittle that function ... just trying to learn/understand how I can apply this to my needs.


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## RGF (Mar 24, 2013)

Mt Spokane Photography said:


> The ability to do this depends on the model of camera.
> With a 5D MK III or the 1 Series bodies, you can do it.
> 
> The others have severe limitations.
> ...



Oops - 5D M3 and 1D M4


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## Badger (Mar 24, 2013)

I find sometimes when I'm shooting sports in a gym, I don't want to go below a certain shutter speed, but sometimes I also don't want my camera going over 12,000 ISO for example and I would like to control the apature. It is sometimes good to be able to make the decision as to ranges of priorities vs. set points. 

So, for example, I might be ok in certain situations with my camera not going under 1/200 sec, and going up to 10,000 ISO, and if the sensor needs more light, then open the lens as opposed to automatically going over 10,000. I know it sounds hairy, but for me, I'm glad to be able to limit how high I allow auto ISO to go.


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## bdunbar79 (Mar 24, 2013)

Rienzphotoz said:


> neuroanatomist said:
> 
> 
> > The 5DIII let's you pick a minimum shutter speed in Av mode up to 1/250 s, in addition to specifying a range for Auto ISO (the 60D and 7D with v2 firmware, but not v1, can set a max for Auto ISO but not a min, and no min shutter).
> ...



Two words: Exposure compensation.

Go to custom menu and set min aperture to f/4 and max to f/2.8. Turn to TV mode, set shutter to 1/500 and ISO to auto. Furthermore, set EC to +2/3 for example. Now you are shooting in auto ISO with +2/3 EC.

You can only do that in 1D series bodies and NOT the 5D3.


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## Rienzphotoz (Mar 24, 2013)

bdunbar79 said:


> Two words: Exposure compensation.
> 
> Go to custom menu and set min aperture to f/4 and max to f/2.8. Turn to TV mode, set shutter to 1/500 and ISO to auto. Furthermore, set EC to +2/3 for example. Now you are shooting in auto ISO with +2/3 EC.
> 
> You can only do that in 1D series bodies and NOT the 5D3.


Damn! ... I got all excited until I read the last line that it is not possible on 5D3 ... bummer :'(


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## TrumpetPower! (Mar 24, 2013)

neuroanatomist said:


> The 5DIII let's you pick a minimum shutter speed in Av mode up to 1/250 s, in addition to specifying a range for Auto ISO (the 60D and 7D with v2 firmware, but not v1, can set a max for Auto ISO but not a min, and no min shutter).
> 
> The 1-series bodies let you specify a range (max and min) for aperture, shutter speed (not limited to 1/250 s), and ISO that can apy to any mode.



The 5DIII also lets you pick an auto shutter speed mode which is roughly 1/focal length. Which is a bit silly, since that puts your 400 f/2.8 at 1/500 when it's definitely hand-holdable well below 1/100. And, as others have pointed out, when you're in M mode but with auto ISO, the 5DIII won't let you apply exposure compensation to the auto ISO.

With ISO being so flexible these days, camera manufactures should really re-think the P/Av/Tv/M modes, and instead let you pick whatever combination of the three variables you care about, let the camera choose the others, and use exposure compensation to override the camera's determination of brightness. Ideally, you'd pick maximum and / or minimum values for all three. Reproducing today's Av functionality, then, would mean the same maximum and minimum values for both aperture and ISO but no limits on shutter speed.

Then again, I almost always shoot full manual...I only find autoexposure useful for when the light is changing too fast for me to adjust for, and I don't tend to shoot very often in those types of circumstances. Hardly ever, these days, in fact....

One final rant. Except insofar as high ISO values degrade always degrade image quality and therefore are always undesirable, as photographers we really don't care what ISO value the camera uses. If ISO ten hundred Brazilian was as clean as ISO 100, would you have a preference between the two? But aperture controls depth of field and shutter speed controls motion blur, both of which we're always looking to vary to artistic effect. So, ideally, for a given scene, you'd set the aperture and shutter to whatever you want, and then let the ISO fall wherever it needs to for a proper exposure. And _that's_ how I want my camera exposure system to work. We're getting there, but we've still got a long way to go....

Cheers,

b&


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## Old Shooter (Mar 24, 2013)

Rienzphotoz said:


> bdunbar79 said:
> 
> 
> > Two words: Exposure compensation.
> ...



I know! I'm with you! Come on Canon - just one little firmware tweak for us 5D3 owners!


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## neuroanatomist (Mar 24, 2013)

Rienzphotoz said:


> neuroanatomist said:
> 
> 
> > The 5DIII let's you pick a minimum shutter speed in Av mode up to 1/250 s, in addition to specifying a range for Auto ISO (the 60D and 7D with v2 firmware, but not v1, can set a max for Auto ISO but not a min, and no min shutter).
> ...



What happens to aperture when you crank up the shutter in Tv? I don't always want to shoot wide open, sometimes I need more DoF. For me, aperture is generally the priority, of course I care about shutter speed but only insofar as it being sufficient to freeze subject motion (1/125 s for 'still' people, usually 1/500 for 'still' birds/wildlife); if the shutter runs up to 1/8000 s in good light, that's fine. Full manual with auto ISO is another option, and I use that, too, especially for BIF (usually 1/1600 s, f/6.3), but with Av and a min shutter set where I want (which is sometimes faster than 1/250), I don't have to worry about, or take time to set, shutter speed. That also keeps my ISOs as low as possible.


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## bdunbar79 (Mar 24, 2013)

Exactly. On the 1D series, you can get really complicated/creative. You can do min and max shutter as neuro states, you can do min/max ISO, and even ISO safety shift. It's really cool!

I need to look at my 5D3 to see what it can and cannot do.


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## RGF (Mar 24, 2013)

bdunbar79 said:


> Rienzphotoz said:
> 
> 
> > neuroanatomist said:
> ...



Another reason to spend $6000 on a 1Dx. If I only an extra $6000 (after buying 500 or 600 II and setting aside $12000 for a 200-400). Need to win a small lottery


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## Mt Spokane Photography (Mar 24, 2013)

RGF said:


> I have tried auto ISO but have yet to get the hang of it. Is there a good tutorial on it?
> 
> Ideally I would like to set a minimum shutterspeed, aperature and maximum ISO. If the exposure could not happen, then I would like to specify which would be sacrificed. Gets complicated very quickly.


On both your 5D MK III and your 1D MK IV, go into the menu system and set the maximum ISO that auto ISO will use.
Then select manual exposure and set ISO to auto. Set both the aperture and shutter speed you want. The cameras will adjust the ISO as required for a good exposure. If it reaches the maximum ISO you have set and still cannot get enough light, it will slow down the shutter speed, so watch out. See pg 166 of the manual.

With the 1D MK IV, see pg 112.


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## bdunbar79 (Mar 24, 2013)

Additionally, on the 1D4, instead of having it slow down shutter, you can have it open aperture if you're not already wide open.


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