F1 focus screen cleaning

[mwelsh]

what should I use to clean the focus screen on my F1. I changed light seals and was doing some cleaning and now I have spots on it that won't come off. i'm concerned it might be something else on there like fungus because when i do seem to get it clean it comes back but it moves around. I never noticed it before and everything else is clean and clear including the lens.

Thanks for the help

 

[holmburgers]

What do you mean it moves around? Are you using a liquid, and when it dries the spots reappear, or is it a stubborn speck that you can't remove from the screen, and you just keep pushing it around?

It's a removable screen, right? Take it out, if you haven't already, and beyond a camel's hair rush, I'd say a lens cleaning solvent might be ok, but I can't say with absolute certainty.

If nothing works, you could get a replacement screen or live with it, as it won't have any affect on picture quality. Good luck!

 

[mwelsh]

I used lens cleaner on a cloth. I did not put liquid directly on the screen. I got one side to go away and then it all seemed to appear on the other side. (same side opposite ends) I will have to live with it probably which is okay. Just looking for experience. Thanks holmburgers.

 

[Mainecoonmaniac]

If it's the F1 N, you could remove it to clean it. I have dust on my F1's mirror and focusing screen and the pictures look fine. I'd just live with it.

 

[dynachrome]

The F-1 focusing screens come in a frame along with a condenser. If you are not careful you might get liquid between the two.

 

[lxdude]

I used lens cleaner on a cloth. I did not put liquid directly on the screen. I got one side to go away and then it all seemed to appear on the other side. (same side opposite ends) I will have to live with it probably which is okay. Just looking for experience. Thanks holmburgers.

Maybe static charge made it all appear on the other side?

 

[mwelsh]

I thought about liquid getting in between something. That very well could be a possibility. I looked on the ebay and found them mostly for 50 dollars. Seemed a little steep to me. There are nine different screens for this camera. All of them for different types of photography. It is the older version F1 for anyone who wants to know.

 

[Andrew K]

OK - don't laugh......

if it moves around then oyu may well have a bug living in oyur focusiing screen. A F1 screen is made up (from memory) of 3 bits - the focussing screen itself, a thin beam splitter glass that sends a portion of the light coming onto the screen to the lightmeter, and a magnifier lens.

What you need to do is pull the screen apart to remove the blob that moves...to do this you need to remove the 2 or 4 screews (I can't recall which on a old F1) and then push on the screen from above. Next remove the tape from the outside of the bundle carefully, and dismantle the screen.

DO NOT TOUCH THE ACTUAL FOCUSSING SCREEN - if you get marks on a focussing screen it can be very hard to clean the screen without leaving a drying mark on the screen....

If you do get foam or dirt on a focussing screen the best way I've found to clean it is to first use alcohol to remove any sticky substances, and then wash the screen in mild detergent, adn leave it to air dry sitting on one corner. You may need to wash it a couple of times before you can dry it withour a cleaning mark, but it does work..

Just reverse above when re-assembling the unit - just make sure you don't tape over the opening where the lightmeter window is in the back of the screen or you will throw out your meter...

And $50 is not unreasonable for a screen - I can remember when I worked for Canon Australia in the early 90's a new screen wholesaled for $109.90 + sales tax.....

If youhave any questions send me a PM - I used to repair cameras at Canon and still have afew bits floating around if you need soemthing..

Cheers

Andrew

 

[John Hermanson]

If the screen is like the old Nikon F type (mounted in a frame, with condenser lens above) the dust may be in between the 2 elements. Using ANY kind of "solvent" on the frosted plastic part of the screen will destroy the etching and stain it. You should limit cleaning to dry compressed air (do not blow on screen with your mouth as droplets of saliva will leave marks), or fine brush. A goose feather is my choice for brushing focus screens. I've heard of washing screens in distilled water. John

 

[Ihmemies]

I'd say the screen is ruined. Once got some of the remains of a mirror dampener goo to a FM's focusing screen. I tried every possible solution I found in my house, excluding iron wool. Normal soap, gasoline, turpentine, isopropyl alcohol, some kind of industrial cleaning stuff which removed even duct tape's glue from my glasses etc. Everything, no success.

I ended up throwing the screen away. It still worked ok and I didn't see any side effects of using cleaning solutions.. they didn't seem to melt anything from the screen But of course I don't recommend trying them if you absolutely don't need to...

 

[elekm]

You can use lighter fluid to remove that foam goo from focusing screens, but if it gets on the matte side, that's a different story.

My method of cleaning one-piece screens is to remove them, clean them using my fingers with dish washing soap under running water. Once it's clean, I hold it securely by the edges, shake off the excess and dry with compressed air. I've done this maybe 30 or 40 times without a problem with all types of cameras.

With two-piece screens, that's a different story, and you have to be very careful.

I also once had to remove a dead ant that had gotten between the prism and the focusing screen (Minolta SRT 202).

 

[mwelsh]

great feedback. sounds like everything you shouldn't do, i did. Lol. I got it so the spots are gone so I'm happy for now. thanks again for all the great advice.