DubiousDrewski wrote:
Also, the seal dividing the viewfinder from the sensor area is not perfect. It will actually allow some light to leak in. This is why the nicer camera bodies, like the D700, have a mechanical blind that you can close over the eyepiece for long exposures.
The neckstrap of my old EOS600, which I use for my 40D, has a rubber part with a viewfinder "cover" built in. You can take it out and put it on the viewfinder. Only downside is that you have to take off the rubber eyecup first...
Only downside is that you have to take off the rubber eyecup first...