How do you clean dust or crap from the viewfinder? I about had a cow while in Glacier NP after a lens change in the car. There was suddenly a big . . .speck (of an unidentified nature) visible when I went to shoot another photo. With one body, I did a ton of lens changes. I thought I was careful. Fortunately, I don't see anything in the images, and shot a blue sky at various focal lengths, and in and out of focus by various amounts. No apparent sensor dust when viewed on LCD at full magnification.

I did search this, but haven't seemed able to come up with the right magic words to get to the previous posts that have covered this.

It's probably on the mirror or underside of the focus screen. In this case, it's easy to clean off with a small, soft brush. Just be careful not to touch the mirror or focus screen with something hard or sharp. Some people would attack it with a blower, but I think that approach usually just relocates the stuff inside the camera; often to a less accessible place, like the top side of the focus screen.

It almost seems to be above the focus screen. I used a soft brush on the mirror to no avail. How can stuff get above the focus screen?

I'll take another look. Thanks.

Normally one removes the focusing screen and cleans the underside of the prism, if that is indeed the dirty area.

EBH

I can't speak with authority about the 5D3, but both the 5D and the 5D2 are subject to this issue. That's the bad news. The good news is two-part. First, this junk has no effect on your photographs. Second, if you are like me, eventually you'll completely overlook this stuff and no longer see it.

It is almost certainly not on the mirror, where it would produce a very out of focus effect if it were visible at all. It is most likely on the focusing screen. There are ways to clean this or have it cleaned, but I feel like it is rarely worth the bother.

Dan

I have used a blower to clean flakes off the chamber side of the focusing screen. I only use 1 or 2 puffs and never canned air.

Ok, but how do you get access to the inner chamber, and what are the hazards? It is a pretty good size piece of junk, and pretty annoying to see inside a New $3500 camera. If it were on the mirror, I could see it. So, I'm pretty sure it isn't there.

Isn't the focusing screen easily removable by pulling down on the tab with the little plastic tool (or a small screwdriver), or does the 5D III have a permanent screen?

EBH

Since the topic of "stuff on the mirror" has come up, it is probably a good idea to add the obligatory reminder to folks to not clean the mirror in the ways you might clean a lens or other things. The reflective material is on the surface of the mirror - not under glass - and you could easily damage it. It is extremely rare to need to clean a mirror and in most cases there is never a need to do so.

Dan

Blow some air on the focusing screen. If that doesn't get rid of, don't worry about it. The focusing screen is very fragile, and you can scratch it very easially. Never touch it with anything. I suspect that more people damage their camera by over cleaning than other common causes. Dust on the focusing screen is merely an annoyance, and it won't affect your photos. Don't be paranoid about dust either. It's a fact of life, and not really a big deal.

Thanks Dan.
When I first saw it, I turned the camera body down and tried to blow it out with a couple puffs from the Rocket Blower. It didn't help. Grrrr. It is a brand new camera. At this rate, I won't be able to see anything through the view finder by 2014.

It looks like a chunk (albeit a tiny chunk) of foam. Like they use for dust seals or light seals or what ever it is. I had it in my old EOS 10S, and it never went away. I was more agressive about trying to get it out on that camera. No sensor to worry about. It was above the focusing screen. My Sony TRV103 Video camera developed a similar issue, and there is nothing to even open! So, this was certainly an auspicious beginning with my 5DIII.

So, I just did it all again. Lens off, tilt body down, blow out with Blower. I then look into an LED flashlight and inspect for dust. This makes the forth or fifth attempt over a one week period. This time. . .it worked.

SPECIAL NOTE**** The secret is, you have to post it online, whine and cry, blubber and bawl, then it will let the crap go. This way, you seem silly.

I recommend this particular method before sending your camera back to Canon.

To quote Roseanne Roseannadanna, ". . .never mind".

Good greif.

Glad you worked it "out". The thread was worth it for the reminder to *leave the mirror alone*!

Dennis M 1064 wrote:
It looks like a chunk (albeit a tiny chunk) of foam. Like they use for dust seals or light seals or what ever it is. I had it in my old EOS 10S, and it never went away. I was more agressive about trying to get it out on that camera. No sensor to worry about. It was above the focusing screen. My Sony TRV103 Video camera developed a similar issue, and there is nothing to even open! So, this was certainly an auspicious beginning with my 5DIII.

So, I just did it all again. Lens off, tilt body down, blow out with Blower. I then look into an LED flashlight and inspect for dust. This makes the forth or fifth attempt over a one week period. This time. . .it worked.

SPECIAL NOTE**** The secret is, you have to post it online, whine and cry, blubber and bawl, then it will let the crap go. This way, you seem silly.

I recommend this particular method before sending your camera back to Canon.

To quote Roseanne Roseannadanna, ". . .never mind".

Good greif.



On a 5DMK3 how did you get into the area above the focusing screen? Unlike earlier 5Ds the focusing screen is not in a carrier and designed to be user changable.

EB-1 wrote:
Isn't the focusing screen easily removable by pulling down on the tab with the little plastic tool (or a small screwdriver), or does the 5D III have a permanent screen?

EBH

As far I see it it is a permanent one. It is not exchangeable.

Dennis M 1064 wrote:
SPECIAL NOTE**** The secret is, you have to post it online, whine and cry, blubber and bawl, then it will let the crap go. This way, you seem silly.

I think you have identified a law of the online world. I know that it has worked for me more than once... ;-)

Dan

(BTW: While the bulb blower can maybe remove dust behind the focusing screen, there is some thinking that being too aggressive with the bulb blower can actually push dust up there, too. Damned if you do and damned if you don't!)

I think you are right Dan. I'll keep the bulb squeezer on a lower setting.

Cheers

I have often use the arctic butterfly to just attract the dust to the brush. I never blow air into the camera - either the focus screen or the sensor.

Had to google that. Interesting. Thanks.