It was beginner luck indeed, or I don't know how I mess it all

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

It was beginner luck indeed, or I don't know how I mess it all

Post by Serge » Wed Jan 20, 2021 10:16 pm

Hello evwryone again. Its me, the chinesse laser guy.

Today I want to tell you about how I prepare new emulsion. I used some 250 blum 10 years old gelatin, so I don't know if that's the reason why it never get liquid at all. It turn out extremely lumpy even though I'm pretty sure the heat temperature was right. The other variant was that I add a drop of clove oil as preservative. Also the lit of the jar was metallic.

I'll prepare some more tomorrow. Wish me luck.

Best regards.

Joe Farina
Posts: 710
Joined: Wed Jan 07, 2015 2:10 pm

Re: It was beginner luck indeed, or I don't know how I mess it all

Post by Joe Farina » Thu Jan 21, 2021 10:16 am

I've read that the properties gelatin can change over time, during storage. Ten years is a long time, I would stick with the gelatin you had the previous good results with. I haven't heard of clove oil with regards to preserving DCG. In the past, with blue exposed "regular" DCG, I found that storage of the emulsion, prior to coating, in a small refrigerator works well. In fact, my best results came after storing the emulsion in a fridge for a period of time (I don't remember exactly how long, maybe a week or so) prior to coating. They do have inexpensive TEC-type fridges (small in size) which may work for this purpose. But I've preferred the ordinary compressor-type compact fridges, they seem to be capable of lower temperatures, and also seem more reliable.

One thing I've found to be helpful in making single-beam test exposures was to include a small fragment of a mirror somewhere in the scene, to reflect a little light directly back onto the emulsion. That way, you can see how bright a mirror reflection would be. This would more closely approach a 1:1 reference to object ratio, and would be closer to the ideal ratio. (In other words, make a crude HOE mirror as part of the scene.) With DCG, the result can be amazingly bright. The mirror needn't be large, just a 1cm fragment of mirror would be enough.

Serge
Posts: 4
Joined: Mon Jan 04, 2021 7:31 pm

Re: It was beginner luck indeed, or I don't know how I mess it all

Post by Serge » Thu Jan 21, 2021 7:01 pm

Thank you for the advice. I think I figured it out what happened. My temperature was too low so the gelatin never melt.

So today I coat some more samples but I think I screw it again because I tried to accelerate the drying by putting the plates over the heat platform. Now they look kind of dark, I may burned them. I'll keep on learning.

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