02-13-2014 01:42 PM
02-13-2014 05:24 PM - edited 02-13-2014 05:25 PM
Do you mean the mirror inside the front of the camera? If so, if the camera is under warranty I would only recommend having it professionally cleaned. That might even be a good idea if it's no longer under warranty, unless you are very confident of your own abilities. It can be "wet cleaned" similar to cleaning the sensor, but has to be done very carefully using the correct cleaning solutions and optical swabs. The mirror is "front surfaced" with vaporized aluminum, very easy to damage, and rather pricey to have replaced. Might be worth a small fee to have it professionally cleaned.
If you are seeing smears within the pentaprism (looking through the eyepiece), those are most likely on the focus screen. Once again, it's a delicate item and using the wrong things to clean it can make matters worse. 5DIII doesn't have an easily removeable and replaceable focus screen, either. It also might be best left to a professional cleaning.
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & PRINTROOM
02-14-2014 10:13 AM - edited 02-14-2014 10:14 AM
Dust on the mirror or screen does not effect the picture. It can be annoying but has no effect on the photo.
Get a Rocket Blower!
03/30/2023: New firmware updates are available.
EOS 1DX Mark III- Version 1.7.1
Speedlite EL-1 - Version 1.0.2
03/30/2023: Product Advisory for EF50 F1.2 L USM
03/30/2023: Product Advisory for EOS R10
2/07/2023: New product announcements!EOS R8 EOS R50RF-S55-210mm F5-7.1 IS STMRF24-50mm F4.5-6.3 IS STMRF15-30mm F4.5-6.3 IS STM
Canon U.S.A Inc. All Rights Reserved. Reproduction in whole or part without permission is prohibited.