ICanon EOS 7d Mark ii, Canon 100-400 lens . In AV mode, jumping to too low ISO, underexposing

[LJbirder]

Taking bird pictures in bright light, AV mode, recently my canon is jumping out of the desired 1250 ISO to way too low an ISO and drastically underexposing the shots.  This often happens when the shutter speed shows at 8000.  This seems to be a new development on my 2 year old camera.  How can I control this to get better shots?

[RobertTheFat]

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@LJbirder wrote:

Taking bird pictures in bright light, AV mode, recently my canon is jumping out of the desired 1250 ISO to way too low an ISO and drastically underexposing the shots.  This often happens when the shutter speed shows at 8000.  This seems to be a new development on my 2 year old camera.  How can I control this to get better shots?

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This is probably completely unrelated, but just in case ...

Since the camera is two years old, be sure it has the latest firmware. I'm too lazy to look it up, but I'm pretty sure there's been at least one update during that time. Indeed, I believe I installed one on my wife's 7D2 within the past few weeks.

[LJbirder]

Thanks for your reply!

[Waddizzle]

In addition to what Robert pointed out, double check your metering mode.  Double check that your small dial on the rear of teh camera isn't changing ISO, instead of selecting focus points, too.

[LJbirder]

Thanks for your reply!  The problem seems to be related to metering of maximum shutter speed of 8000.  Often taking birds there is a sky background.  Perhaps the camera is deciding that the shot can't be taken at the selected ISO.  When the shutter button is half depressed, that is when it randomly drops during shooting to ISOs that are way too low (such as from 1000 to 250) and the photos are extremely underexposed.   I have tried lowering the ISO to something intermediate and that doesn't always help.  I am not sure whether the error is due to the meter going bad or to user error on my part.  This seems to happen more often than it use to.   But many shots are still coming out perfect.  I am losing about half of my shots when the light is really bright.   Further thoughts welcome! 

[diverhank]

Your camera is behaving very strangely...not very normal at all.  In Av mode, when there is enough light, it should not be underexposing, period.  I can't think of any crazy options that might have caused the problem but I'd clear all settings back to default, just in case.

That aside, I'd never let my camera controls too many things...you are letting it take care of both ISO and shutter speed! 

I normally shoot full manual but when I shoot birds, due to time constraints, I'd use M with Auto ISO.  That way I have full control of both aperture and shutter speed.  Since the 7D2 let you do exposure compensation in M mode, I'd dial that in to compensate for bright backgrounds or dark/light  birds.

[LJbirder]

These are some great answers.  I routinely do exposure compensation.  Will try your suggestions such as M with Auto Iso.  And returning to default.  Thanks!

[TTMartin]

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@LJbirder wrote:

Taking bird pictures in bright light, AV mode, recently my canon is jumping out of the desired 1250 ISO to way too low an ISO and drastically underexposing the shots.  This often happens when the shutter speed shows at 8000.  This seems to be a new development on my 2 year old camera.  How can I control this to get better shots?

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Sounds like Exposure Safety Shift is kicking in.

Why it underexposes? I don't know.

EDIT: If you have your Auto ISO range set to a really low number, it might be when Exposure Safety Shift kicks in, it gets forced to that really low ISO. Set your Auto-ISO range to use anything from ISO 100 to ISO 16,000.

Instead of AV Mode and ISO 1250, try Manual mode with Auto ISO. I want to control my shutter speed when shooting wildlife/action.

On my 7D Mk II with EF 100-400 L IS II, I use Manual Mode with Auto ISO +1/3 stop Exposure Compensation. Wide open on the aperture, for Birds in flight a shutter speed of 1/1600, for Birds not in flight 1/1250, and for Birds hiding back in the dark of branches 1/800.

7D Mk II with EF 100-400 L IS II +1.4X TC III

476mm, 1/1600, f/8, ISO 500

7D Mk II with EF 100-400 L IS II +1.4X TC III

560mm, 1/1600, f/8, ISO 1600

7D Mk II with EF 100-400 L IS II +1.4X TC III

560mm, 1/1600, f/8, ISO 640

7D Mk II with EF 100-400 L IS II +1.4X TC.

560mm, 1/1600, f/8, ISO 500

[LJbirder]

Thanks for the great ideas.  Will try.  My lens is called the Canon EF 100-400 f/4,5-5.6 IS II USM.  I routine shoot at 5.6, as do many of my birder friends.  However, I notice that my camera controls allow a wider range of options.  I am not sure how this works with my lens.  For shooting birds, do you have a recommendation with this lens and camera setup?  How should I be varying this with conditions?  Great bird photos, by the way!  

[TTMartin]

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@LJbirder wrote:

Thanks for the great ideas.  Will try.  My lens is called the Canon EF 100-400 f/4,5-5.6 IS II USM.  I routine shoot at 5.6, as do many of my birder friends.  However, I notice that my camera controls allow a wider range of options.  I am not sure how this works with my lens.  For shooting birds, do you have a recommendation with this lens and camera setup?  How should I be varying this with conditions?  Great bird photos, by the way!  

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Yes, the 7D Mk II and the EF 100-400 f/4.5-5.6 IS II USM is an awesome setup for bird photography. That is what I use also, though I've been using it with the Canon 1.4X EF Extender III, for a little more reach.

Note my Edit in the post above, I think your Auto-ISO may be set to too small and low of a range, and that is why when Exposure Safety Shift kicks in that it underexposes.