I got the viewfinder with the uncoated glass installed in the SF1n last night and the result is, well, interesting. The image is now much brighter and very much sharper. The interesting part is with the uncoated glass the out of focus highlights tend to take on a 'star like' quality. It's almost like having a full screen microprism, not sure if this is good or bad yet, I'll have to take it out for a stroll today. I assume the effect is due to internal reflection since this is a good optical quality glass. One thing I did notice is that the original plastic eyepiece is slightly concave on the outside surfaces. This does not appear to have any diopter property and I am assuming it is to reduce relection, somewhat like a "ghostless" filter.
Even uncoated the glass makes a big difference in the finder image quality, similar to cleaning the optics in a rangefinder it's an "Oh wow! Didn't know what I was missing" kinda thing. Don > -----Original Message----- > From: Don Sanderson [mailto:[EMAIL PROTECTED] > Sent: Thursday, February 24, 2005 5:59 PM > To: pentax-discuss@pdml.net > Subject: RE: Glass viewfinder optics for the SF1n(Resend) > > > Hi Alan, I thought that was you. > I agree, it's an amazing difference. > I just now finished cutting one from a old Olympus RC > rangefinder cover glass. > It's not coated but it was the right thickness, a diamond bit > in the Dremel made short work of shaping it. > Even without the coating I can see a radical difference looking > thru the finder assy. > It'll be interesting to see what it's like compared to the > coated one on the camera. > I have to get up the guts to disassemble the other 1n, those > little switch contacts bend SO easily! :-( > >Don