Canon 5d mark 3 transmissive LCD screen

[awinphoto]

Ok, we have a slight issue here...  With my new 5d, I have noticed it attracts dust on the mirror/LCD almost every time I change lenses...  Never was an issue with my 7d or 5d2 or prior cameras.  Anywho today I took a canon brand rocket blower today to knock out the dust and looked into to viewfinder to find 2 small streaks in the scene. After looking around it was the plastic screen above the mirror assembly. I took a dry clean anti static cloth...  Nope...  Tried blowing warm air on it (like you would glasses) and wiping thoroughly, looked clean but streaks were still there. Ok, seriously annoyed now I get rubbing alcohol and qtips and lightly clean it...  That's when things started taking a turn for the worst...  I start getting a faint circle outline and more streaks, as if by doing so is removing some coating on the underside of the plastic. Anywho after trying to clean it as best as I could, looking through the VF has a large circle outline that extends from the top to the bottom of the screen perfectly around the center "spot" circle in the middle, and various imperfections in areas...  Basically the top plastic in front of the transmissive LCD is going to have to be fixed/replaced. Anyone had any issues like this with maybe the 7d or 5d3?  Looking through the VF is saddening, AF and the actual transmissive part appears perfectly fine, and photo is perfect as always...  Any suggestions before I prepare to get raped my canons repair services?

[neuroanatomist]

Never had this issue with the 7D...but then, I never took a Qtip to the focusing screen, either.

[Abraxx]

I only use a Qball from Giottos (or other quality blower, which does not blow particles from inside out), never ever would I rub around on the focus screen, especially if I can not remove the screen from the Cam.
If the qball fails, bring it to the service, but what you decribe sounds more like that you ruined the screen and its not a failure of the Cam and/or focusing screen construction.

Sorry, but thats my impression. 

PS here in Germany, Canon offers to clean your cam for free within 6 months after purchase, thats a free offer from them.
So on a new Cam, I would never start cleaning like crazy meyself, but frist ask the good Canon Service....

[awinphoto]

Thanks for your comments...  After doing so shoots and playing around with it... the AF still works flawlessly, and the screen looks farily decent besides the imperfections on the extremities.  I will have the camera sent in this week and let you know.  Regarding the cleaning thought process, i've always been under the impression that surface areas of the camera were generally cleanable, i.e., mirror, VF, sensor, LCDs, and the focusing screens used to be interchangeable, but shoot, figured that should be cleanable from at least the surface, you shouldnt be forced to send your camera in to be cleaned for heavens sake... It appears there is/was some sort of matte substance or film or something that has been wiped out, but functionally the camera still works without missing a beat.  Anywho after close inspection it appears that it is a simple plastic piece that probably only costs Canon 20 cents to replace, but i'm bracing for around $150-200.  woo hoo...  lesson learned and hope i saved anyone else who thought they could clean their own screens. 

[Mt Spokane Photography]

The plastic focus screens just need a brief touch to transfer oil or debris to them.  Oil was likely transferred your fingers to the rocket blower when you touched it, and thats all it takes. They are difficult to clean, but can be cleaned with ultra pure alcohol (ordinary alcohol has impurities and debris that only makes it worse, and a qtip will add to it.
 
I had dust on my 5D MK II mirror that would not blow off, I loosened it with a lens cleaning cloth and then blew it off.

[awinphoto]

The plastic focus screens just need a brief touch to transfer oil or debris to them.  Oil was likely transferred your fingers to the rocket blower when you touched it, and thats all it takes. They are difficult to clean, but can be cleaned with ultra pure alcohol (ordinary alcohol has impurities and debris that only makes it worse, and a qtip will add to it.
 
I had dust on my 5D MK II mirror that would not blow off, I loosened it with a lens cleaning cloth and then blew it off.

A very plausible scenario... Thanks for your input.  I assume it would be too late to use the ultra pure alcohol now...  I never realized how delicate that little friggen piece of plastic was, never really had that problem before on prior cameras... maybe the odd piece of dust on the mirror I'd blow off or dust on the sensor which I would blow off, but nothing like this.  Oh well... Hope this thread helps some other poor soul before they run into what I did.