Milkyness in dcg
Posted: Wed Feb 20, 2013 6:37 pm
MilanKarakas wrote:I have different set of issue: milkiness. And something that is not related with process temperature. No matter cold or warm first bath, holograms appear milky. Recently discover that after baking at 100C for 3 to 4 minutes, hologram is much more clear, but also lacking of diffraction efficiency.
Tried light fixing before exposure, light fixing after exposure, tried light fixing at emulsion side, glass side, both... no matter what I do, it is or milky or there is almost nothing on the plate.
And, my last batch of the plates are with too thick emulsion and too much dichromate in it (100:12:3), so for recording at 450 nm, often I am getting terrible UV shifting (I can't say blue shifting, because laser is already blue). Tried to skip 70% alcohol bath in order to get broadband reflection hologram, but what I got is just whole plate broadband, while object is really not visible. Transmission holograms are somewhat okay, probably because emulsion shrinking does less blue shifting. Not sure.
Best wishes,
milan
---