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New user of a Canon 7D - less than 50 shots taken. Last night, I needed to take a quick picture of something that was on my cell phone with my Canon 7D

I propped the phone up against a white pillow in a very well lit room. I zoomed in to just focus on the screen while in full AUTO / Green mode. ISO was showing 7200 and the exposure light wouldn't stop flashing, so I couldn't take the photo. Any ideas why this happened? Something about potentially being too close to the source? There was bright light in the room - and the flash didn't pop.

I tried recomposing - still had no luck. I WAS able to take pictures of other things in the room. I eventually just flipped to CA and took the shot.

Is this normal behavior - Why did the camera choose an ISO that wouldn't allow for the shot to be taken, rather than using the flash? And auto-focus squares were clearly lighting up.

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What mode was your 7D set to when you first attempted to take the shot? –  Global nomad Feb 12 '13 at 15:34
    
I was shooting in full auto / green mode initially –  Seth Feb 12 '13 at 15:38
    
Ah, I hardly shoot with my 7D set to the full auto mode. Will experiment when I'm at home later to see if I can duplicate what you saw. –  Global nomad Feb 12 '13 at 15:43
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What lens were you using and what focal length was it at? –  whatsisname Feb 12 '13 at 16:50
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My guess is that you were at too close of a focusing distance. I would try stepping back. If we knew what lens you were using we could recommend the distance it will focus at a minimum. Also, ISO 7200 isn't that high for a 7D indoors without a flash. Was this at night or during the day(with windows?) –  dpollitt Feb 12 '13 at 17:23

1 Answer 1

Never seen a camera not shoot because of exposure and I've had a Canon 7D too. I did not like how it metered by default and photos were more often over-exposed than with other cameras but it still took the shot.

A camera refused to shoot though if it cannot focus. You were probably too close and the camera light up all focus points as opposed to some to let you know. All lenses have a minimum focus distance which is usually specified at the wide-angle settings. Some also specify it at another distance and it should be stated in the manual.

The other case when a camera can refuse to shoot is if the flash is still charging. In this case you just have to wait a little before releasing the shutter and there should be a light to tell you when.

The Auto ISO chooses a sensitivity to get an exposure is deemed acceptable (even though you or I may disagree) at a shutter-speed which is safe to hand-hold. There is a maximum but I do not remember which it is for the 7D.

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Just a pedantic clarification. A 7D will refuse to shoot if it cannot focus using One Shot AF. However for those of us who e.g. have it set to use Back Button Focussing and AI-Servo, it will happily take a shot without confirming focus. –  Conor Boyd Feb 12 '13 at 20:00
    
The 7D v2 firmware includes menu support for limiting the max ISO that the camera will choose in Auto ISO. A 7D bought in the last 6 months at least should have the v2 firmware. –  Conor Boyd Feb 12 '13 at 20:02
    
Yes, obviously customization can change this to Release-Priority as opposed to Focus-Priority, something I do not expect someone have taken 50 shots to have time to change yet :) –  Itai Feb 12 '13 at 20:32
    
In Auto (green) mode by default the focus mode is set to AI Focus only and can not be changed. AI Servo custom settings would not apply in Auto mode. –  Michael Clark Feb 12 '13 at 20:55

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