[leepsj]

I have been using a Canon 350D DSLR for a few months. Recently, I find that there is one small thread / scratch from looking through the viewfinder.

First, I thought it is some dust but when I took apart the lenses. It still appear. If it is dust on CMOS, it would not be possibly seen inside the viewfinder ? Also, I have tried to clean the CMOS and once finished the picture taken seems to be dust free when inspecting on the LCD monitor.

There fore, I suspect it is some dust / scratch in the viewfinder. I have been trying to clean (with blower) the viewfinder but the thing is still firm in its position. I m not sure whether it is dust from the "inside" of the viewfinder which I could hardly clean.


If some one could adivse on that, I shall appreciate very much.


Any one please advise.

[Gowest]

You should also check the focusing screen which can be seen when you turn the body upside down. Be careful not to scratch it!!!

[leepsj]

Do I have to take apart the lenses ? and raise the penta-mirror ?

I am not sure where the focusing screen is ?

[wlachan]

If you see the scratch which is sharp (more likely to be dust I believe) when looking through the viewfinder, it is on the inner side of the focusing screen. When you peeping inside the camera from the camera mount, you see the mirror, and the screen. Now, you must exercise extra caution not to touch the surfaces of the screen because it is soft plastic. Trying to wipe or rub or even brush it with anything and it will be damaged permanently. The only thing you can do is to blow off the dust "gently" with a rubber blower (never use compressed air). However, I have no idea if 350D has user removable screen. Not all cameras have this feature. Dust trapped between the prism and the screen is very common and does not cause any problem, so if in doubt, better leave it as it than sorry. A new screen will cost you $200+, with labour extra.

[leepsj]

I took the camera to Canon CS last Saturday, there are very few (only me and the other customer) persons for service.

The girl also added that their R & M department is now offering delivery service (to your home or to your office at your option) after repair.

Thanks for your advice !