Yep, both my 640's come out a bit lower and to the right of aperture centre as you look at it from the frontparticularly the 640nm beam is both quite a bit lower at the aperture and comes out at a bit of an angle. Strange.
Yep, both my 640's come out a bit lower and to the right of aperture centre as you look at it from the frontparticularly the 640nm beam is both quite a bit lower at the aperture and comes out at a bit of an angle. Strange.
Bought some of these a while back,
4 mounts for $15... can't beat that for value per $
They're aluminum sandblasted with glass bead
http://cgi.ebay.com/ws/eBayISAPI.dll...m=260512129355
or maybe 4 mounts for a couple bucks?
http://cgi.ebay.com/ws/eBayISAPI.dll...m=220620056431
surplus shed and thorlabs have some prism pairs about $110 for an uncoated set..
http://www.thorlabs.com/newgrouppage...149&pn=PS875-B
I ordered a pair of these for $6 per piece to give it a try:
http://www.surplusshed.com/pages/item/pm1081.html
The 45 degree angle is not ideal (30 would be better) but the AR coating is nice!
and a pair of these for $8 per piece:
http://www.surplusshed.com/pages/item/l3442.html
But they uncoated and 20 degree angle probably make it less good.
They also have a selection of cylindrical lenses to try.