# Manual Mode T2i with auto ISO



## buzz (Oct 1, 2012)

I recently found that in manual mode if I set aperture and shutter speed but leave ISO on auto the metering will adjust the ISO to get the "right" exposure.
This is like AV mode but I also get control on shutter speed.

This can be very useful.
One situation is where I know my aperture but I want to vary shutter speed based on focal length to avoid camera shaking. Now I can let camera metering take over and bump up ISO when I am using larger focal lengths with faster shutter speed.

How many of you guys use manual mode this way?

What are your thoughts?


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## neuroanatomist (Oct 1, 2012)

It's great. The 7D was the first camera (outside of the 1-series) to offer this capability, and subsequent cameras have it (not sure about the T3). I use it on my 7D and 1D X for a 'birds in flight' C# setting, 1/1600 s and f/6.3, letting the camera pick the ISO in a specified range. The implementation on the 7D was hapmered by the inability to set a cap on Auto ISO, so it would run right up to 3200 - that was fixed with the v2 firmware.


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## Bob Howland (Oct 1, 2012)

I use that mode often but i would use it more if the 7D and 5D3 would let me specify what to do with aperture and shutter speed when the ISO limits are reached. Currently, the cameras just overexpose or underexpose. I've never used the comparable feature in a Nikon camera but I understand that Nikon's implementation is more sophisticated, even in their consumer DSLRs.


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## neuroanatomist (Oct 1, 2012)

Bob Howland said:


> I use that mode often but i would use it more if the 7D and 5D3 would let me specify what to do with aperture and shutter speed when the ISO limits are reached. Currently, the cameras just overexpose or underexpose.



You can enable Safety Shift (it's off by default), in which case the camera will override the manually selected setting(s), including a selected minimum shutter speed, to obtain a correct exposure.


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## Richard Lane (Oct 1, 2012)

I don't believe safety shift works in Manual mode. However, Auto ISO is like a safety shift in Manual mode. In Av and TV mode you can use AV/TV safety shift and in AV,TV, P mode you can use ISO shift when you have a fixed ISO set.


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## sandymandy (Oct 1, 2012)

My 1100D can do this too. Auto ISO in M mode. Plus it always allowed me to set maximum auto ISO which wasnt available in 7D til the latest update if im correct. Im just not sure what this thread is all about. Everything is just normal like this isnt it?


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## neuroanatomist (Oct 1, 2012)

Richard Lane said:


> I don't believe safety shift works in Manual mode. However, Auto ISO is like a safety shift in Manual mode. In Av and TV mode you can use AV/TV safety shift and in AV,TV, P mode you can use ISO shift when you have a fixed ISO set.



Correct, it doesn't. Oops. Looking back, I had this thread open at the same time as the recent min shutter speed thread, and I was thinking of Av mode as I was replying (thus, the comment about min shutter speed in my reply!).



sandymandy said:


> My 1100D can do this too. Auto ISO in M mode. Plus it always allowed me to set maximum auto ISO which wasnt available in 7D til the latest update if im correct. Im just not sure what this thread is all about. Everything is just normal like this isnt it?



Good to know, thanks. 

The point of the thread is that many previous cameras, before the 7D, did not have the ability to do this. The 5DII, for example. If you set M mode and Auto ISO, the ISO was fixed at 400.


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## Richard Lane (Oct 1, 2012)

buzz said:


> I recently found that in manual mode if I set aperture and shutter speed but leave ISO on auto the metering will adjust the ISO to get the "right" exposure.
> How many of you guys use manual mode this way?
> 
> What are your thoughts?



I use this all of the time and find it works great. As you mentioned you can set your DOF and SS, and still get a normal exposure every time, especially in varying lighting conditions.

The only time that it doesn't work well is if you want to use +/- EC to raise or lower your exposure settings. Sometimes you just need to override the cameras exposure settings, since the meter can be fooled.

For those conditions, I'll use AV or TV, depending on what is more important and then I'll use +/- EV with a fixed ISO, with ISO safety shift enabled (which I always leave on). 

Without getting too technical, if light is limited, I'll use a custom shooting mode in AV with a wide open aperture, and then I'll set my minumum SS to 1/1000 sec (custom setting in 1DX) for sports with Auto ISO. E/C can also be applied to this, since I'm not shooting in manual mode. In sports it's important to control your background, SS, and exposure compensation, and the above setting alllows me to do all of those things. 

For controlling SS of other cameras, I use TV and auto ISO or fixed ISO with safety shift (depending on which settings controls my aperture/background better) to avoid blurry shots, or I would use Manual mode with Auto ISO.

Rich


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## buzz (Oct 1, 2012)

Thanks for sharing your experience and some more tips.

I shoot handheld (travel) and so these settings are very useful to me while I vary my focal length on 24-105mm.
I remember I was shooting in AV mode, it was hard to get shutter speed I like while zoom in and out without setting ISO to higher number.

I think camera manufacturers should at least provide an automated way to set shutter speed base don focal length. That would make AV mode usable again especially with large zooms. I think Nikon D800 has it.

Overall I like auto ISO on canons.
I also use Nikons (5100, 7000) and I do not like the auto ISO feature there.
I have to manually turn off auto iso in menu there. I do like that I can set min shutter speed unlike my T2i.

But with this new mode I discovered I am going to be manual mode 90% of the time

Here is what I am doing these days
Set shutter speed to 1/60 at 24mm and 1/200 at 105mm, desired aperture and shoot away. 
This is assuming aperture is your primary concern and we are changing shutter speed is only to get sharp pictures at lowest possible ISO.

Would you recommend what I am doing to casual shooter?


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## buzz (Oct 1, 2012)

sandymandy said:


> My 1100D can do this too. Auto ISO in M mode. Plus it always allowed me to set maximum auto ISO which wasnt available in 7D til the latest update if im correct. Im just not sure what this thread is all about. Everything is just normal like this isnt it?



Noting wrong, I am just excited to find this and hence sharing with others.
Also wanted to find out what situations other photogs are using this mode.
My situation is varying focal length that requires varying shutter speed at a constant aperture.


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## sandymandy (Oct 1, 2012)

neuroanatomist said:


> The 5DII, for example. If you set M mode and Auto ISO, the ISO was fixed at 400.



Uhm then whats the point of choosing auto instead of fixed ISO urself? Seems like some kind of bug to me. But 7D also confused me that u couldnt even set an auto iso limit for such a long time!


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## neuroanatomist (Oct 1, 2012)

sandymandy said:


> neuroanatomist said:
> 
> 
> > The 5DII, for example. If you set M mode and Auto ISO, the ISO was fixed at 400.
> ...



There would be no point, which is why Auto ISO in M mode is useless on the 5DII and other pre-7D bodies. 

Even with more recent bodies, it could be better - say you've got your 5DIII in M mode, Auto ISO, and want to keep the same SS and DoF, but want to over- or underexpose by a stop. It would be great to be able to apply EC...but you can't.


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## zim (Oct 1, 2012)

Is it correct that this limitation (I also have this issue with the 500D) has been fixed in the 7D through a software update only?


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## neuroanatomist (Oct 1, 2012)

zim said:


> Is it correct that this limitation (I also have this issue with the 500D) has been fixed in the 7D through a software update only?



Yes. But given that your camera has already been replaced (three times over now), I would not expect an update for you.  The 7D firmware update seems to be something of a stop gap, since Canon is not yet ready to release a 7DII.


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## buzz (Oct 1, 2012)

Google is awesome.
Very nice article written here. 
http://www.dpreview.com/articles/0206161199/an-in-depth-discussion-of-m-auto-iso-for-canon-slrs


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## zim (Oct 2, 2012)

neuroanatomist said:


> zim said:
> 
> 
> > Is it correct that this limitation (I also have this issue with the 500D) has been fixed in the 7D through a software update only?
> ...



:'( :'( :'( :'(
A well, still it's got a great little (under-rated I think) sensor


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