A little more of beginners luck

Starting point for beginners questions.
Serge
Posts: 4
Joined: Mon Jan 04, 2021 7:31 pm

A little more of beginners luck

Post by Serge »

Hello.

Been doing more samples. Here is the best result that I had on last batch.

https://www.instagram.com/p/CJ7zFdGjpVf ... wo39f7bh0v

532 nm ?mW chinese/battery laser
DCG 50/6/1.5
Veil coating/ 24 hours drying
5m exposure
No optics
5m in the dark after exposure
Fix with1m light
2m on cold running water
IPA 50/50, 80/20, 100
Dry- same light as fixing for 1hour

That's all for now.

Greetings.
Joe Farina
Posts: 804
Joined: Wed Jan 07, 2015 2:10 pm

Re: A little more of beginners luck

Post by Joe Farina »

Nice repeat. Without considering the stability of the laser, so many things can be refined and experimented with, in regards to DCG. Film formulas, coating methods, and the all-important processing technique.

Your laser is unstable, but I wouldn't be concerned with it, for now. Those dark bands across the chest of the object are so-called "depth contours" (this is also known as the sliced bread effect). The laser is changing wavelength slightly during the length of the 5-minute exposure.

Lasers are the perpetual problem of the holographer. When the time comes for a better laser (and you no longer want to see the dark bands), I would suggest a Coherent 315M-100, which is a ~100mW 532nm laser. They are usually on eBay:

https://www.ebay.com/itm/Coherent-DPSS- ... SwjwdeQuTi

Of all the lasers I've used, this has proven to be the best and most reliable for holography. I'm still using the one I bought ~15 years ago. I'm still curious about the actual output of your laser. If it's a high output laser, much more than 100mW, then that might be contributing to your success. I've only worked with blue-exposed DCG, or dye-sensitized DCG with 532/633nm. With the dye-sensitized DCG (which is complicated), even 30mW of green light is enough. But I don't know what your film formula requires. Dave B. has done a lot of work with 532nm DCG, it might be worthwhile to review his posts on this forum, and get a better idea on how much 532nm light you need with your film formula.

Although I haven't tried these myself, this may be a good bet for a new laser (from Dave B.), and it has the benefit of being very inexpensive:

https://www.ebay.com/itm/Osram-Green-La ... OSw889eNC1~

Good luck, and I look forward to seeing more of your results.
Serge
Posts: 4
Joined: Mon Jan 04, 2021 7:31 pm

Re: A little more of beginners luck

Post by Serge »

Hey Joe, thanks a lot for your response. I'll keep on improving on the emilsion/coating part of the process. I'm already in touch with Dave. So very soon I hope will be trying osram laser.

Have a nice day.
Martin
Posts: 131
Joined: Sat Apr 04, 2015 2:36 am

Re: A little more of beginners luck

Post by Martin »

Litiholo used to sell a blue (450nm) laser module - see: www.litiholo.com/hologram-lasers.html). Its power is only 5 mW though. Of course that's pretty moderate. Nevertheless, I could make holograms on DCG, FEG, photopolymer and diazo materials. The laser module I have works nicely without any mode-hops. Most of the above mentioned recording materials are substantially more sensitive to 450nm than 532nm. So you should be able to expose holograms up to 4x5" without too much problems.
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