sasaki@harvard.UUCP (Marty Sasaki) (02/19/86)
The reason that plexiglass is bad to shoot through is that it scratches easily. The scratches diffract the light that goes through them and generally degrades the image. Glass is better because it doesn't scratch as easily. Plexiglass actually transmits more light than glass and doesn't have the green tint that glass has. -- ---------------- Marty Sasaki net: sasaki@harvard.{arpa,uucp} Harvard University Science Center phone: 617-495-1270 One Oxford Street Cambridge, MA 02138
hagerman@friday.DEC (02/21/86)
x Is there or isn't there a weird effect when light goes through plexiglass? I made a contact print frame once with a new, scratch-free piece of plexiglass about 1/4 inch thick. Contact prints made with it came out *very* bad, with lots of strange things at the edges of objects in the pictures. I changed to a regular piece of glass about the same thickness, and things became normal. I thought that maybe there were more internal reflections or something... Doug Hagerman
billw@Navajo.ARPA (William E. Westfield) (02/21/86)
Stressed plastics will do all sorts of weird things to the polarization of a light source, which may or may not have any effect on picture taking or using it in contact printers. More likely is that plexiglass is easier to deform into non-optically-flat surfaces. BillW