Eye picece cover?

I was out yesterday using my 40D on a tripod. I was using mirror lockup on some nice scenery. It was overcast but bright, on several shots the exposure was very dark. Same exact scene, didn't move the camera. Thinking about it last night it dawned on me, did I need to cover the eyepiece?
Thanks for any information,
David

OK guys, I was forced to read the manual. Yup, that's what I did wrong, let light in the back. I've been shooting Panasonics G series and it doesn't seem to bother them.
Can you believe all the information in the manual, sorry.
David

Alternatively (or even additionally), pre-meter using the viewfinder and shoot in manual.

You should have an eyepiece cover that came with the camera. Mine is always on the camera strap.

Glenn

Your thumb can work pretty well as an eyepiece cover, too. Yeah, I know... pretty low tech. But, hey, it works!

amfoto1 wrote in post #17114898
Your thumb can work pretty well as an eyepiece cover, too. Yeah, I know... pretty low tech. But, hey, it works!

Hey - a thumb may be low tech, but it's still digital! (Wacka wacka!)

JohnB57 wrote in post #17115213
Hey - a thumb may be low tech, but it's still digital! (Wacka wacka!)

Good one!

JohnB57 wrote in post #17115213
Hey - a thumb may be low tech, but it's still digital! (Wacka wacka!)

lol

That works only in English, though.
Cameras not having an optical viewfinder where the light metering sensor is located right inside the eyepiece aren't sensitive to light entering from the back. But in Canon EOS cameras, the light metering sensor is located right above the eyepiece, inside the prism cover, so it's close to the eyepiece.

The 1DX (1D-series in general) has a built-in eyepiece shutter.

I found the eyepiece cover on the strap real fiddly to use. So as one has to remove the eyecup anyway, I bought a spare one, and cut a small black rectangle out of black plastic and fixed it to the spare eyecup with very thin clear double sided tape ( the sort of stuff used to stick bump stops on surfaces ).

I found this far easier to mount and dismount, a better blackout fit and relatively cheap.
Its also a good spares backup in case one lost the original eyecup piece during the covered eyepiece shoot.

Glenn NK wrote in post #17114623
You should have an eyepiece cover that came with the camera. Mine is always on the camera strap.

Glenn

I cannot remember my 5D2 coming with an eyepiece cover. Do all Canons normally include these?

Yes, a rubber thing sitting on the camera strap.

amfoto1 wrote in post #17114898
Your thumb can work pretty well as an eyepiece cover, too. Yeah, I know... pretty low tech. But, hey, it works!

Not for long exposures - you'll probably cause small vibrations in the camera, ruining the image.

Lowner wrote in post #17116318
I cannot remember my 5D2 coming with an eyepiece cover. Do all Canons normally include these?

Yes. It's black, square, about 3/4" x 1" (20mm x 25mm). But if you leave it on the strap, you could touch the strap and cause vibrations in the camera.

G

You only need to cover the eyepiece when metering is done. Once exposure starts it doesn't matter.
There's a small risk that stray light could enter the eyepiece, reflect backwards through the prism, pass the raised mirror, reflect in the matte black mirror box and finally hit the sensor during exposure. But you kind of need to take night time photos and aim you car headlights into the eyepiece to make that a real problem.

Glenn NK wrote in post #17114623
You should have an eyepiece cover that came with the camera. Mine is always on the camera strap.

Glenn

Thanks Glenn