Cleaning focusing screen

No, the price of the Canon focus screens are extremely cheap from the Canon Parts Center. T1i focus screens are $1.98/ea and Canon 40D/50D focus screens are $2.00/ea. Shipping is $6 UPS regardless of order size.

In the past, they used to package the focus screens in individual plastic bags wrapped between soft dustless sheets. However, recently, they started to package the focus screens in small plastic "boxes" which houses 5 focus screen. It saves them money since they focus screens are no longer wrapped individually, however, I found that there are "more" dust on them!

I recently got a pack of 5 for my T1i; out of the 5, only 1 had no imperfections -- the rest either had small black dots or micro-scratches on them.

@amfoto1, please do not quote me out of context. I never said to put a naked qtip in there, if you read my post again, you will see what I did. It works and quite successfully. There is no part of the original qtip exposed, and I use a qtip because there is really nothing there that could scratch anything if you inadvertantly do something silly.

I washed my focus screen under warm running water and detergent and then blow dried it with a Rocket Blower. Sounds crazy I know, but I had a spare grid screen and the standard screen with a stain on it. So if it all went pear shaped, I would just fit the grid screen. However, it worked really well and left the screen in pristine condition.

If you wash the focus screen with water, rinse it thoroughly with distilled water several times and let it air dry suspended by a corner. All water from a tap has minerals and will leave a film.

gjl711 wrote in post #9033275
If you wash the focus screen with water, rinse it thoroughly with distilled water several times and let it air dry suspended by a corner. All water from a tap has minerals and will leave a film.

It will only leave a film if you dont dab it dry or blow it forcibly dry. Evaporation is bad!

I'll just add a precision matte screen into my cart at Adorama while I order my 1Ds Mark II, then...
This happened while we were playing around with an EF-S lens at work. We both own 5D Mark IIs, and the screen falls out, and he picks it up. Oy.

Trainboy,
If you friend touched the underside of the actual focusing screen, he touched the fresnel lens side. I have successfully cleaned these with 90% denatured alcohol from the drug store. I first removed the focus screen from the camera, then holding it by the sides, I used a qtip saturated with alcohol to cover the focus screen. Next step was to "gently" roll the qtip across the focus screen several passes till you have covered it while still very wet with alcohol. Next I dried it with several qtips again by rolling them, not scrubbing them across the screen. This WILL leave qtip lint on the screen so don't get anal about this stage. I did the same to the ground glass top and when done, blew them off well with a rocket blower. After checking it with a 8x loupe, I reinstalled it in the camera with tweezers (the replacement screens come with a nifty pair) and it was clean as a pin. I also have 35 years as a tech working on equipment large and small. Your skill level may vary. I agree, focus screens are reasonably priced and replacement is a viable option if you are not comfortable with the skills involved. The lower surface of the screen is a VERY sensitive surface easily damaged by too much pressure, but not impossible to clean if not physically damaged.
David

Bill Boehme wrote in post #9032092
Get a better friend.

I hooted when I read about using a t-shirt to dry the screen.

I mean I figured, old soft T shirt, nothing better to wipe or dry with right?

rguil15 wrote in post #9049892
I mean I figured, old soft T shirt, nothing better to wipe or dry with right?

If it was 100% cotton, probably nothing too bad about that. We corvette fanatics won't let anything but 100% cotton or microfibers touch our cars, that and Zaino (or equivalent)!

TeamSpeed wrote in post #9033626
It will only leave a film if you dont dab it dry or blow it forcibly dry. Evaporation is bad!

Never dab a focusing screen to dry...you chance leaving dust or lint if you do not manage to damage the fragile focusing surface. Distilled water rinse and air dry is best!

A good amount of time dipped in water with some dishwashing detergent (oil emulsifier) or in alcohol can remove finger oils.

tommibear99 wrote in post #9032286
No, the price of the Canon focus screens are extremely cheap from the Canon Parts Center. T1i focus screens are $1.98/ea and Canon 40D/50D focus screens are $2.00/ea. Shipping is $6 UPS regardless of order size.

In the past, they used to package the focus screens in individual plastic bags wrapped between soft dustless sheets. However, recently, they started to package the focus screens in small plastic "boxes" which houses 5 focus screen. It saves them money since they focus screens are no longer wrapped individually, however, I found that there are "more" dust on them!

I recently got a pack of 5 for my T1i; out of the 5, only 1 had no imperfections -- the rest either had small black dots or micro-scratches on them.

I had a 40D focusing screen and they come in a clear plastic box with a removal tool and cost considerably more than $2..more like $35.

You must be talking ahout something other than a focussing screen, I think.

bohdank wrote in post #9052252
I had a 40D focusing screen and they come in a clear plastic box with a removal tool and cost considerably more than $2..more like $35.

You must be talking ahout something other than a focussing screen, I think.

Focus screen $2.00. Removal tool $33.

Yeah, I find it hard to believe the focus screen could be only $2.00

I have some dust in the view finder, so I order a new focusing screen with the grid. I got it today and replace it, unfortunately, the dust is "inside" somewhere. After I remove the focusing screen, I can see those dust, but doesn't come off with the blower, so, I bravely try to remove it with my Pentax sensor cleaning stick, it's like a stick with a sticky tip. Since it is for cleaning sensor, I think it is safe to use it a bit on that thing. However, after a couple unsuccessful tries, I concluded that the dust is in the inside. It seems there is a piece of plastic covering the space, and the dust is sitting right on top of the plastic.

sad

I got this 5D used, I don't know how the dust can get into it. Is it a sign that the owner doesn't take care of this camera carefully?

Also, is it safe to clean the mirror with lens paper or microfiber cloth?

bohdank wrote in post #9052252
I had a 40D focusing screen and they come in a clear plastic box with a removal tool and cost considerably more than $2..more like $35.

You must be talking ahout something other than a focussing screen, I think.

No, the focus screen for the 40D/50D were only $2 at the Canon Parts Center. However, you need to buy 5 of them. It doesn't come in a "nice" case or have the removal tool.

Wilt wrote in post #9052019
Never dab a focusing screen to dry...you chance leaving dust or lint if you do not manage to damage the fragile focusing surface. Distilled water rinse and air dry is best!

A good amount of time dipped in water with some dishwashing detergent (oil emulsifier) or in alcohol can remove finger oils.

I guess I have just been lucky with the last 4 screens I have cleaned. Oh well, ignorance is indeed bliss.