Focusing screens, have you put one in?

I am looking for advice about installing/reinstallin​g focusing screens in a 1D series camera.

I think mine may have moved after a fall.

I don't have 1D4, but can't imagine it's all that different from other Canons with user interchangeable focus screens....

From the front of the camera, with the lens removed, look above the mirror for a little tab right in the center of the horizontal black baffle. That's a latch that should be seated if the frame holding the screen is still in place. If a bump has dislodged the screen, the tab will be unlatched.

You can release the latch by pressing the tab with a fingernail. (Be very careful not to touch the mirror.)

But if it's still latched (flush with the edge of the baffle), I don't believe there is any way the focus screen might have shifted. It's held pretty securely in place by the frame.

If you are seeing a problem in the viewfinder, I would suggest checking the diopter adjustment... maybe it got bumped and is out of adjustment. To adjust that, remove the rubber eyecup around the viewfinder eyeport. Under it you will see a dial. Either remove the lens or defocus it a lot manually, then point the camera toward a light source such as a bright window. Looking through the viewfinder, turn the dial until the markings on the focus screen appear as sharp as possible. Done. This is on page 40 of the manual.

Thanks amfoto1, I don't think it is the diopter. I have never messed with the focusing screens before.
I would like to check the screen before I send the body to Canon for service.

I think I'll remove & reinstall the screen before I decide to send it to Canon.

On the 1DIV the latch(you'll see right bellow the red lens alignment dot) needs to be pulled straight out. The frame that holds the focus screen in place will then swing down. There's very little room for movement, on mine there is pretty zero front to back but a bit side to side. Anyway it's easy to check, just be careful not to touch the focus screen(as mentioned it has a little tab you can grab) or mirror while in there. Just swing the frame back up and push it up until it latches(you'll probably need to use you finger nail right next to the latch to push it up far enough).

Before I changed my focusing screen on my 1D IV, I went on YouTube and there are videos there that show you how to do it. Great resource.