Refitting a prism

peterqd · Expire: 2014-01-04

I want to clean the top surface of the focussing screen in my Pentax K2, which means removing the prism. Taking it out doesn't look like a big problem but there is a foam seal round it which has disintegrated. The foam is an orange colour and seems finer than the door seal stuff, and I don't have anything else I can replace it with.

I'm not sure of the function of this foam, does it just cushion the prism or is it needed to block out light? Anyone have any experience of doing this job? Thanks

bob955i · Joined: 15 Apr 2007 Posts: 2495

Sounds like it's mainly for anti-rattle purposes - like mirror cushion foam.

Try using light seal foam as long as it's not too thick if you have it.