I have the canon 5d mark III, when used in manual as I half press the shutter button the marker when zeroed out or located where I want it to be for the exposure will show a second marker. Why does it do that?
Are there actually two indicators at the same time? When you push half way it should show you an indicator of where the exposure currently is. I thought that it won't show any before pushing half way, but I don't have my camera with me to check. Are you sure the 'second indicator' isn't just the exposure indicator?
If you are talking about about the exposure marker it is just showing you what the camera thinks what would be a correct auto exposure. This allows you to compare your dialed in manual exposure with the camera's calculated exposure.
Edit: I see skirball just posted ahead of me, I think we are saying the same thing.
