Holographyforum.org / holowiki.org

Thank you for the insights, Din, I appreciate it.

I've attached two pages from a 1979 Applied Optics paper by Chang and Leonard: "Dichromated gelatin for the fabrication of holographic optical elements". With regards to angular bandwidth, I found it interesting that they reported such large variances with regards to dichromate concentrati...

Thank you Jody and Din. This is another one done this morning: P1010034.JPG It's not as bright as the other one, probably because I was trying for a more narrowband result. I used more green laser light, and the colors improved somewhat. While in the 20C 91%, the colors looked quite good, but after ...

Since the Gallery has been slow lately, I would like to post a photo of a hologram done Friday: P1010028.JPG This is DCG (1.2g potassium dichromate, 6 grams gelatin, 70ml water), coated with Mayer bar, and plate aged 20 days at room temperature. Lab was 61F and 58% RH. I used two laser wavelengths (...

Thank you Din, I appreciate it.

Din wrote: ↑Tue Oct 17, 2023 8:43 am Your hologram seems to reflect mostly in the green.

Second photo showing purplish tint

I've noticed that in some of my DCG holograms which turn out bright, there is a purplish tint which shows up in transmitted light. The below Denisyuk was done this morning. The second photo in the next post shows the same hologram in transmitted light coming through the window, with the purplish tin...

As always, thanks for your helpful comments, Din. Regarding angular bandwidth, I'm noticing how much it can be increased by broadband processing. The below hologram was done this morning, with warm water (25C) and warm 100% (58C). Though it has a lot of noise, it's fairly bright and has a decent amo...

Remember also, if there's water in the film, you have to fix for longer to draw out the water. Don Broadbent and his student Augie Muth both had humidifiers in the coating room to control the water content that seeped into the film during the drying phase. If you don't draw out the excess humidity,...