How to clean...

[James Learie]

The focusing screen in my AV-1?

 

[Dubious Drewski]

You mean this thing?

Well, I assume you'd clean it like you'd clean any SLR, with air, a brush, or my recommendation: both!

 

[Battou]

Just how much "Cleaning" does it need.

One has to be cautious cleaning a focusing screen. I hate to say this but disreguard what Dubious Drewski said, do not take air to your screen, there are several reasons for this.

I Use a Q-tip, because I have problems with brushes leaving hairs, considering it's almost always strey hair I am removing from the screen it kinda defeats the purpose. You should know by heart the grinding patern of the screen and always go with the grain and do not apply pressure. If you go agenst the grain or apply pressure you could inadvertantly grind it down further and then it won't work properly. The effects won't be visable right away but they are cumlitive.

If the screen has some forign substance on it that requires a heavy cleaning like my AE-1 and my Pentax H-2 did. The above still applies, do not try to force what ever it is out of the screen. Again go with the grain and do not apply pressure this time with a little bit of a cleaning solution. I've used rubbing alcohol in the past and saw no ill effect but I would try to stick to something less aggressive. Also do not sit there and clean it till it's gone, work it out steadily over time and multiple cleanings of the whole screen. If you work a single spot you could inadvertantly grind it down further possibly and become uneven.

Additionally make sure you don't beat the tar out of your mirror. It may sound easy enough but, I'v bumped a few mirrirs over the last couple years, it ain't as easy as sounds if you get careless.