50d - think i have a crack behind the focusing screen

anoble66

Hi,

Hope someone can help. The other week after flying, and setting up the camera I noticed what looked like a hair just on the left when you look through the viewfinder. I removed the focusing screen today and behind it I can still see the mark / crack....I think its a crack.

Has anyone any ideas that might help? I will go into the camera shop on Monday but just hoping for some advice in the mean time? This camera is only a couple of months old and never taken any knock of any kind...:(

thanks for the help

Fajitas!

Looks like a hair?

Sounds like a hair

I doubt it'd be a crack without a serious fall and damage done to the rest of the camera. Take off the lens and see if you can see anything on the mirror. If you can't, then look at the focusing screen and see if the hair is on that, chances are it is - I'm not sure if you can change screens on the 50D, so I won't go further for the time being

anoble66

thanks fajitas.....its definitely not a hair though, tried going over the area gently with a q-tip. I did remove the focusing screen already, its not on there but on the mirror behind it......not sure how else to describe it.

Fajitas!

Keep your Q-tips out for the moment! You don't want to drag any cotton wool in there for the time being!

The problem with where it is, is it's incredibly difficult for me to ask to see a pic of it. Well, at least if the screen is removable on the 50D, then that'd be where a hair (I'm still convinced it's a hair! :pac: ) would get in. Do you have a rocket blower? If you do, give it a few blasts of air* and see if anything moves around. Don't use your own breath though.



*for the dust snobs out there, I'd rather some dust on my sensor and something that's affecting my focus gone

anoble66

hi - ok will keep my q-tips to myself :pac: Just taken a couple of shots of the problem area on the mobile, not the best quality but hopefully you can see it.
So, if I take out the focusing screen, its the mirror that has the problem. But on closer inspection its almost on the other side of that mirror.....problem is I dont think I can take that out.

Here are a couple of pics:-






Thanks for your help!

Fionn

two questions!!!

does the fibre/mark/scratch/crack appear out on your photographs?

does it effect outo-focusing in any way?

if the answer to these is no - i'd suggest that you leave it, use a rocket blower ok, but scrubbing with cotton buds is going to make the problem worse.
Its possible that it might be actually behind the low pass filter so that air blowing or other methods wont work.
I notice that theres another mark on the lower right beneath the right focussing point.

I realise you want to have a clear view and these would be annoying to say the least. I've a camera that has something like a tiny smudge (oil or something) that used to wreck my head - got it after changing the focussing screen, it doesnt come out in the photographs and now i've gotten so used to it i dont notice any more.
good luck with it anyway

anoble66

Hi Fionn.

I have just re-checked and the mark does not appear on any pictures and it does not affect the focus.....I am heading to my local shop tomorrow and let them take a look......things like this drive me mad so I cant just leave it :rolleyes: