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.
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.