dust on focusing screen

[montreal]

Greetings to all. I am new on this forum. :eek:
I have two questions.

I have dust on my focusing screen (300d). I called Canon and they suggested using a light brush, but that only added more dust, I'm afraid. I used a blower and now it's not so bad, but there's still some left. When does dust on the focusing screen become a problem?

Also, now I'm paranoid that the guy at the other end of the line didn't know what he was talking about and that I might have damaged the focusing screen. It's probably okay but just in case... what would be the symptoms of a damaged focusing screen?

My apologies if this has been asked before... I checked, but only a few pages back...

edit: just to be clear the dust is on the outside (lens side, not viewfinder side) of my screen.

[robertwgross]

Dust on the focus screen only becomes a problem when you find the view objectionable.

If you have carefully blown or brused it off, then that is about all you can do without getting out your wallet.

If you fiddled with the focus screen badly, then you might see a difference in focus from one side to the other, or similar symptoms that would indicate mis-alignment.

It does not hurt to run a cotton swab around on the external part that goes next to your eyeball.

---Bob Gross---

[Sicily1918]

I had the same problem -- it was one speck, but it was right there, taunting me (:p to all that don't believe me)... I did whatever I could think of and found that, if you persist long enough (read: are stubborn), the hand blower will work. I didn't touch the screen with anything but air, and it got it out.

Also, what Bob said -- clean the eyepiece out with a swab or lint-free cloth, as it may be there. Lastly, check the mirror and make sure the dust particle isn't there.

[deedas]

I had this same problem and asked about it here. Its very annoying at first but I've come to live with it. If any more gets in though, I'm heading straight to someone that can clean this.

[montreal]

:) Thank you all for your helpful answers :)

The specks are quite tiny at this point so I guess I'll just stop worrying about them and have the screen professionally cleaned eventually (when more dust comes). It's just insulting to have them there. I'm pretty sure they're telling each other evil jokes about me when I'm not looking. ;)

If you fiddled with the focus screen badly, then you might see a difference in focus from one side to the other, or similar symptoms that would indicate mis-alignment.

I don't seem to have any focusing anomalies, even at maximum aperture, so all seems fine and I'm reassured now, thanks to you.

But just out of curiosity, what would a scratched focusing screen look like through the viewfinder and how would it affect picture taking?

[PhotosGuy]

But just out of curiosity, what would a scratched focusing screen look like through the viewfinder and how would it affect picture taking? It might look like a dark, or light line depending on the lens focal length & lighting conditions. It won't affect the pic at all, except to drive you nuts! ;-)
A word on blowers. Do you keep it capped when it's in your bag. You do realize that after it's compressed, it sucks up whatever is in your bag? And then you blow it on your sensor!

[Jonny]

DO NOT TOUCH THE FOCUSING SCREEN WITH ANYTHING SMALLER THAN YOUR ELBOW!!

If you can't live with the specks that are there and a blower won't shift it then you can get it changed by a Canon repairer. I had mine done when i had a 300D and it cost me £30, plus a 100 mile round trip.
Why did i have it changed? Well because i touched it!!! It bugged the hell outta me until i took a chance and wiped it with a lens cloth - big mistake. It smeared it up, i think it was actually scratched, and it looked 100 times worse.
My 20D has a speck on it but i don't let it get to me now, i learned my lesson.

[montreal]

Thank you photosguy for your answer. It's nice to know.

DO NOT TOUCH THE FOCUSING SCREEN WITH ANYTHING SMALLER THAN YOUR ELBOW!!

If it's that fragile why did the Canon guy I spoke with (Canon customer service) actually recommend using a lens brush??? Was it an isolated case of a customer service rep not knowing what he was talking about? or is the Canon helpline just unreliable? ???