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Hello, this is the single longitudinal mode coherent laser used, coherence length 50m :cry: :cry: It doesn't look like a coherence problem. When that happens, there are contour fringes (light and dark bands across the image of the object ). This corresponds to the coherence length going in and out ...

Din wrote: ↑Sat Nov 30, 2024 2:46 pm The idea was to harden the surface enough to delay water penetration into the emulsion.

That's a new concept to me, thanks.

Thanks!

Thanks for mentioning the fixer concentration. It seems that some holographers use it straight, other prefer it diluted. I'm looking forward to trying the Kodak fixer. I tried it once with DCG, a long time ago, but I can't remember why I stopped using it. Today's result proves how important post-exp...

I did another exposure this morning, and changed a few processing variables. The plate was 29 days old at room temp, which seems like a long time to me, but it still (apparently) had some softness to it, since the upper left part shows quite a bit of milkiness/frostiness, suggesting softer gelatin i...

If you're using HX200, which is a slow material compared to silver, then I would avoid using wood. As a table, you can use a concrete paving slab from the home center, resting on a bicycle inner tube. The floor appears to be wood, which isn't ideal, but may not cause a problem. I don't recommend san...

Thanks for the log entries. Having a form to fill in is better than my method of taking notes, because without a form, if you forget something, it may not be written down. With a form, the "vacant space" is obvious, and reminds you to fill it in. I like this idea, thanks.

Thanks for the thoughtful analysis. Kubota was my first guess, thanks for confirming this.

I've read quite a few papers on holographic recording materials using gelatin, but don't seem to recall any which had two or more layers of gelatin. In the case of DCG, say we laid down a 10-micron layer using one film formula, and then, after that one had dried, laid down another 10-micron layer on...

Well, since I'm now retired and Joy is busy making diffractive optics holograms on polymer, I can come clean :D :lol: Thanks for the very valuable info. My gelatin was melted at 50C and I may have seen the same blobs after the plates gelled. They were perfectly circular and about 5mm in diameter. T...