08-22-2015 07:27 PM
Solved! Go to Solution.
08-24-2015 12:12 PM
It is likely dust resting on the "top" of the focusing screen. The screen is a frosted surface (usually the top is frosted and the bottom is glossy). The camera is projecting a focused image onto this screen because the distance from the lens, to the imaging sensor inside the camera is exactly the same distance as the distance from the lens, to the mirror, to the focusing screen.
When you look through the viewfinder, you are actually looking at an image being projected onto the focusing screen (sort of like a rear-projection TV screen). This would sort of be like having dirt on the "inside" of the panel of a rear-projection TV -- it's not on the surface you can touch and would require removing the focusing screen to blow the dust off the back of it.
When you take a photo, the reflex mirror swings clear and the light path goes directly from the back of the lens to the imaging sensor without ever going through the focusing screen -- hence it will not affect your images at all (you could have rocks up in that chamber and it wouldn't affect the images.)
My 5D II camera has user-swappable focusing screens (Canon sells optional screens) and they include a special pair of tweezers with a hooked end to make it easy to open the focusing screen compartment and swap the screens without actually having to "touch" the screen with your fingers. But your camera isn't designed to have swappable focusing screens (although third parties do make them.)
While it is possible to remove the screen and clean it, it must be done with great care because it is easy to damage that screen (especially if you've never done it before and aren't sure how to remove and re-insert the screen.) Since the dust wont show up in an image, I would leave it alone. If you choose to attempt clean it anyway, it's your camera and your choice to accept the risk. But it could lead to a more costly repair if something goes wrong.
08-24-2015 12:23 PM
THank you very much for this input! Would you know if there is a Canon service department where you can send it in for cleaning?
08-24-2015 12:41 PM - edited 08-24-2015 12:48 PM
@Adrianpz1 wrote:THank you very much for this input! Would you know if there is a Canon service department where you can send it in for cleaning?
Canon has three service centers in the U.S. One in Jamesburg, NJ, another in Newport News, VA, and a third in Costa Mesa, CA.
If your camera is over a year old and out of warranty, you also might look for a local camera repair shop. This is a fairly standard cleaning service that most experienced techs can handle.
Again, I would only have the viewfinder (mirror/focus screen actually) cleaned at the same time as having a much, much more important sensor cleaning done. Just ignore it in between cleanings.
***********
Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & EXPOSUREMANAGER
08-24-2015 12:30 PM
@Adrianpz1 wrote:
That's just a minor nuisance and trying to clean it with anything more than a gentle puff of air from a bulb blower risks doing damage to the camera that will be expensive to fix.
Those spots are probably on the focus screen. During exposure the mirror flips up, covers the focus screen and preventing light (or anything else) entering the mirror box with seals around the rim of the mirror. Only then does the shutter open (usually for a fraction of a second) and expose the sensor so that the image can be made. So, there is no way that these specks can appear in your images. These are just a very minor nuisance to you when looking through the viewfinder and will have no effect on your shots.
So I'd strongly recommend you leave them alone until some day when you have the camera's sensor professionally cleaned. Ask them to clean the mirror and focus screen at the same time. But, be warned, even if you get it back sparkling clean you will see more stuff in there soon. Every SLR/DSLR ends up with stuff in there sooner or later. Get over it.
Something you wrote in your original question concerns me. I don't know what you mean by "airing out" the camera. You don't need to "air out" cameras. In fact, if you are letting it sit around without a lens or without a body cap on it, that's why you are seeing dust specks in there. You should keep a lens or body cap on the camera all the time, except briefly such as when changing lenses. Those will reduce the chance of stuff getting inside... and ending up on the mirror(out of focus) or focus screen (more in-focus and what you are seeing, I think)
***********
Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & EXPOSUREMANAGER
08-24-2015 01:01 PM
Thank you for the input. By "airing out" I meant with the rocket blower. Sorry I shuold've mentioned that. No air cans used. Your information is very helpful! I always tempt to change lens where there is no dust, and faced down. I can wotk with the spots on here, just didn't know there was a big thing cleaning it out. I'll leave it as is, that is until theres more and both focus and mirrors. Thanks again!
03-06-2017 07:55 AM
Hello Adrianpz1,
I just noticed on my Rebel T3i a little dead insect when I look through my viewfinder right below one of the focus points. It is really annoying to me, but after reading your questions and the answers I wonder if I should "get over it" as someone had said. What did you end up doing? Did you have it cleaned?
Sincerely,
Summerlee
03-06-2017 08:03 AM
@Summerlee340 wrote:Hello Adrianpz1,
I just noticed on my Rebel T3i a little dead insect when I look through my viewfinder right below one of the focus points. It is really annoying to me, but after reading your questions and the answers I wonder if I should "get over it" as someone had said. What did you end up doing? Did you have it cleaned?
Sincerely,
Summerlee
An insect is organic. It can decay, which can raise the possibility of mold or mildew taking root in your camera. The mold and mildew spores can spread to your lenses, contaminating everything you own, including a new camera body.
Since it is foreign material that is organic in nature, I would have the camera professionally cleaned. Remember, you're not just cleaning your camera, you would be protecting your lenses, too.
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