I had been contacted a few years ago about such a solution for LF negatives using high powered 365nm UV LEDs in the enlarger head, but after some calculations decided to not go that way...
I had been contacted a few years ago about such a solution for LF negatives using high powered 365nm UV LEDs in the enlarger head, but after some calculations decided to not go that way...
Klaus
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/ for UV Images and lens/filter info
http://photographyoftheinvisibleworld.blogspot.com/ my UV diary
Klaus
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/ for UV Images and lens/filter info
http://photographyoftheinvisibleworld.blogspot.com/ my UV diary
Klaus, thank you for your considered views and experiments
Some are lax on Copyright
Quoting sources IS a problem as few were taught to do that
Tin Can
Klaus
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/ for UV Images and lens/filter info
http://photographyoftheinvisibleworld.blogspot.com/ my UV diary
Well, about the topic: today things ahev changes a bit, as high powered 365nm UV LEDs have gotten much cheaper and using some in a suitable condensor head would bring down exposure times considerably - IF and only IF a suitable UV passing lens would be used. THAT still is quite a challenge still, as many do not work. A suitable triplet lens with single or no coating would do, but would have to be stopped down - AND there is the focusing issue as those leses have considerable focus shift.
One would have to use some paper with fluorescent paint to focus on, then replace that with the photo sensitive paper and do teh exposure...
Klaus
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/ for UV Images and lens/filter info
http://photographyoftheinvisibleworld.blogspot.com/ my UV diary
http://photographyoftheinvisibleworl...6_archive.html
Coatings sometimes block UV, so depending on the lens version a difference may be there.
Probably a condenser type enlarger may be better for UV LEDs, as difusser type are way less efficient.
Klaus
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/ for UV Images and lens/filter info
http://photographyoftheinvisibleworld.blogspot.com/ my UV diary
I thought that was the easy part. I made some big negatives but gave up trying to make the platinum paper work right and went back to commercially produced silver paper.One of the biggest hassles in alt processes is making a full-size positive
Where on this picture is indicated that it is not to be copied, cited, or otherwise used? Given that I found it in Google and I have no idea about your site - file a claim with Google. Or close your site from indexing by search engines.
And there is no need to scream like that - excessive emotions negatively affect health )))
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