eye focus?

[New_Zealand]

I was looking at my 5d and was wondering does anyone have a really good way to make sure your shots are in focus when you look through the eye piece? It has a dial next to it and as I turn it the focus goes in and out but how do I really know it is on the button when I think it is focus? What if my eye is out of focus and needs glasses? Has anyone else wondered about this too?

[Crafters of Light]

You are talking about the Diopter adjustment.
The trick I use is to use any camera graphics on the eyepeice veiwfinder and set that to the sharpest focus I can see, ignoring any scene on the background.
This way I know I have taken care of any eye perscription issues like you are concerned with.
I then look to using the camera lens focus to adgust the scene/subject to match the sharpness of the graphics.

[nigelbb]

If you are looking through the viewfinder then you are by definition not shooting video as the mirror flips out the way in Live View. Rely on the autofocus. It's better at this stuff than you are.

[gonzo_entertainment]

Really miss the old split focus screens that were common in film cameras. Without one focusing through the eyepiece is basically impossible. Even for stills I always use the live view.

[CC Rider]

For a quick check, zoom all the way in and rack the image as far out of focus as you can. Then use the diopter to focus on the viewfinder markings.