The viewfinder cover - to use or not to use

[nate42nd]

I am getting ready to take to star shots and also night shots of the valley in which I live. I have a remote shutter release, I have all the settings I want to use, but some people are telling me to cover the viewfinder with the little rubber/plastic thing that came with my T1i. Do you use it for long exposure? If there isn't much light to the rear of you....I don't see how it could help much. does it? Thanks

[Mark1]

It depends on the ambient light you are shooting in. And how you are metering. Light entering the viewfinder can give a false exposure reading on the meter. I dont think you will have a problem at night though. Most likely you will not be useing the internal meter, but trial and error to ballence if you are including some ground in the frame. Or known exposures for just catching the stars.

The actual exposure is not effected with the light in the viewfinder as the mirror blocks almost all light when it flips up.

Just do a test. shoot some without, and some with. it takes 2 seconds to put it on. Night shots with very little ambient, I dont think will have a visible difference. will

[nate42nd]

It depends on the ambient light you are shooting in. And how you are metering. Light entering the viewfinder can give a false exposure reading on the meter. I dont think you will have a problem at night though. Most likely you will not be useing the internal meter, but trial and error to ballence if you are including some ground in the frame. Or known exposures for just catching the stars.

The actual exposure is not effected with the light in the viewfinder as the mirror blocks almost all light when it flips up.

Just do a test. shoot some without, and some with. it takes 2 seconds to put it on. Night shots with very little ambient, I dont think will have a visible difference. will

Thanks for the information. I saw a page in my manual about when to use it, but cannot seem to find it again. I will have to look for it. I think the viewfinder cap may have to do with live view mode.....Thanks for the night shot info.

[Mark1]

It will be irelivent in Live View. The mirror has to be up for the live view to work. So the light coming in the viewfinder is blocked.