How do you clean the view finder?

I have search utube on how to clean the viewfinder. I hope i am not alone in this annoyance. I change my focusing screen. I thought that's the one that is dirty. Do i have to sent it to Canon to be clean? I have a 50D..

Any help is appreciated. THanks Sam

Rocket Blower first, soft dry brush second.
If you remove then you have more options.

You could follow this process the 50d is similar in design to the 5dm2.
Watch out for the tiny screws, dropping them into the mirror box is a recipe for disaster.

http://shimworld.wordp​ress.com …-the-5d-mk-ii-viewfinder/

[QUOTE=lannes;11965755​]You could follow this process the 50d is similar in design to the 5dm2.
Watch out for the tiny screws, dropping them into the mirror box is a recipe for disaster.

http://shimworld.wordp​ress.com …-the-5d-mk-ii-viewfinder/

Thank you, for the site. This really help. I have to brave my self to do it.

If you choose to do the repairs shown at that site.... well all I can say is good luck.

The author of that article made one major mistake, but was lucky. I would cover and protect the mirror before removing any of those parts. The mirror is front-silvered with aluminum, very delicate and easily scratched. Replacement of a damaged mirror is not a do it yourself project, very expensive... Figure in the hundreds of dollars to have it done.

Even protecting the mirror, dropping one of those parts inside the camera, getting the shims back in there wrong or a bad slip can be a disaster.

Likely it would cost about $25 or $35... maybe $50 tops to take the camera to a local camera technician and have them clean it. Might be worth checking into.

First be aware that a speck in there is just a nuisance. It won't show up in your images. The mirror flips up and covers the focusing screen during exposure.

Next try to determine exactly where the speck of dust is... If it's in focus it's on the focus screen. If it's blurred a lot it's on the mirror. If it's blurred a little, it's above the focus screen.

About all I'd do myself would be puff away any dust on the mirror or the bottom of the focus screen with a bulb blower, or if it's a little stubborn brush it off very lightly with a super clean, very soft brush. If called for, I'd also remove the focus screen, using the little tool, and puff away any dust on the focus screen or the bottom of the sensor display. Beyond that, I'd leave it to a pro to do the cleaning.

Sometimes it's not dust, too. There are foam light seals inside the mirror box that can shed small particles. If they are starting to crumble, a repair tech can replace them. The foams often have glue on them and if that gets onto the mirror or focus screen it will ruin it.

Another thing that sometimes shows up on there is a speck of oil, perhaps from the mirror or shutter mechanism. Touching it will just smear it and make for a more difficult cleaning job.

Overall, I think the best policy is to hand the job to an experienced repair tech and pay them a few dollars to do it. In the meantime, just live with the speck and don't worry about it.

It's not that difficult I do this process all the time, here are the tips I've discovered. You do need to be careful and take your time.

1) you need a small needle plier (eyebrow type) to hold the small screws as you remove or replace them. You hold the screws with the pliers as you screw them in.This prevents them from dropping into the mirror box.

2) There are 2 small tab hooks on either side of the focusing cradle latch one large and one small, these need to be levered up slightly (one side at a time) by the smallest flat head micro screw driver, to release the shims and SI screen. On reassembly they need to be levered up again, usually I just hold the shims and SI up against the against the tabs with the focusing screen and cradle, after they have slotted into place. Then when I lever up the tabs the shims and SI screen flick into place. You can do one side at a time.

3) remember the orientation of the shims and the order they are positioned, there are different sized tabs on the bottom of each shim that align with slots in the the mirror box.

4) remember the tab orientation on the SI screen if you put it in back to front, then you will loose your AF box lighting.

5) everything should go back in without forcing, it will just swing into place if everything is aligned,
if it's not sitting properly just jiggle the shims and the SI screen until they fall into place, don't press too hard as the shims bend easily but also are easy to flatten out again. I often just turn the camera slightly at an angle with the top facing down, everything should fall into place.

6) The focusing screen only fits one way as well, when looking into the camera the largest tab is on the right as it goes into the cradle.

7) After removing each screen (focusing and SI screen), by looking into the viewfinder each time, you can isolate which surface the dust is on. This way you don't clean something you don't need to.
Most of the time the dust will be on either side of the focusing screen.

Sometimes the dust is on the bottom of the pentaprism block which can be swabbed by bending a swab to get the right angle.

6) Never use the blower on any of the screens while they are in place, all this does is blow the dust deeper in the viewfinder system.

7) Always check at each step of the reassembly, through the viewfinder, that no new dust has entered.

Good luck