• Please use real names.

    Greetings to all who have registered to OPF and those guests taking a look around. Please use real names. Registrations with fictitious names will not be processed. REAL NAMES ONLY will be processed

    Firstname Lastname


    We are a courteous and supportive community. No need to hide behind an alia. If you have a genuine need for privacy/secrecy then let me know!
  • Welcome to the new site. Here's a thread about the update where you can post your feedback, ask questions or spot those nasty bugs!

Dust, ye in the Pentaprism?

Ger Bee

New member
I've a new 1DMKIIn, new meaning a few months old but it had dust in the viewfinder area, no harm but distracting, anyway, I made the situation worse myself, before I realised that the dust was "built in" from the factory.

I’m buying a new camera next week and want to send the other one for cleaning, free, preferably, so to strengthen my hand are there any incidents of dust in and around the pentaprism hosing?


New member
Have you tried cleaning the bottom surface (the one you can see looking into the chamber) of the prism the same way you would clean a sensor? I've had the occasional bit of dust show up there in every SLR I've owned since the early '60s and it's always been cleanable with just a little care.

I use the sensor brush technique first nowadays. Haven't needed more so far.

Ferenc Harmat

New member
That's unusual...

...Inside of the viewfinder? Never had that with my previous 1DMarkII, before migrating to the 1D MarkII-N.

What I did found on my previous cam. is dust/spots underneath the focusing screen, which had to be removed, cleaned (NOT blowed), then re-assembled, and then clean with EXTREME care the mirror-finish, to remove slight traces of humidity/condensation and also dust that could easily get back inside the shutter chamber.

Try that out, and make sure you work in a totally clean, directly-lit spot, so you can see what you are doing.

Good luck!

Stan Jirman

New member
I just borrowed a 2nd 1Ds2 for a job to take along with my own 1Ds2, and it looked like a pig sty in the viewfinder. But the remedy was pretty simple: unlatch & remove the focusing screen, blow some air from a can, and re-install the focusing screen. This has worked for me with all 1-series bodies for the past what, 20 years, and I am sure it will apply to the 5D as well since it too has interchangeable focusing screens.

Ger Bee

New member
Thanks for the replies.

Yes, I did remove the focusing screen and blow around in the lower prism area, I was not careful enough and simply deposited more dust, while the dust I as trying to get at remained.

I’ll try again, thanks.

Michael Tapes

OPF Administrator/Moderator
best to do the blowing in a humid/clean environment. best for the usual person is the bathroom, after running the shower for a while to get some moisture in the room, so that any dust is not flying around the room. YMMV