A few weeks ago I made a prototype. The thought was to possibly make a kit. The one here in the photos has been through a lot. I learned a lot too. Notes: Pics:

Hi Edward, I built a led UV exposure unit a few years ago and used 20 strips of 5050 uv LEDs. I spaced them about 1 inch apart on centre. The unit covered 24 inches by 48 inches. The strips were self

And now, a blast from the past. Somewhere in COX Optics is a formula for spacing sources in order to give minimum variation over a surface. I used it to design and build my light box in my NYC

One of my students recently purchased an LED Unit from NUARC. https://www.mrprint.com/equipment/starlight-uv-led-screen-exposure-system I was curious regarding the LED Bulbs used in it and read in

Bonsoir Jean Here are some plans by Kirk Roger (also a list member) https://www.facebook.com/groups/AlternativePhotographicProcesses/permalink/10158027642902749 which will be the basis for my build.

Hi John and all ! Some years ago, I built my UV exposure unit using 8 fluorescent BLB 24" bulbs (each was 40 W), mounting them using twin fixtures and this unit is very efficient.

See the link here: http://gregbrophy.com/blog/how-to-make-a-uv-led-exposure-box

Greg, thanks A short description of the UV LED arrangement It does not give the distance between the strips, but there is a photograph of the arrangement from which you can get an idea as to how they

My BL Bulbs are 3 inches apart and about 5 inches from the frame. Best regards Alan

My fluorescent tubes are 3/4 inch apart. I think it's helpful to design your system so that you can vary the distance between the light source and the printing frame. My frame is 4 inches away from

Hi John, Usually 1 inch between them will be sufficient. Make sure the LED are not coated with waterproofing and that they are really the right wavelength and not just purple lights. The good ones are

Hi list members Those of you that own/have built a UV exposure unit, can you tell me the gap between each LED strip you have? Thanks John -- John

Hope it works for you....be careful not to overheat it....and if you use this screw-cap https://www.dwk.com/duran-high-temperature-red-pbt-screw-cap-gl-45-with-ptfe-silicone-cap-liner-292402807 and

Thanks a lot, Udo, I will soon try this method, quite simple and well described. Salvatore

Dear Salvatore, polymerized formaldehyde is paraformaldehyde see https://en.wikipedia.org/wiki/Paraformaldehyde Paraformaldehyde is used in molecular biology for perfusion of organs.....that means

Hi, does anybody know how to recover a polymerized old solution of formaldehyde? Thanks. Salvatore

This was posted by Tim (see original email at bottom) to Pure Silver. I thought it would be of interest here...

I found the most important thing at a lens was its MTF test, but I ask where are the results for each l/mm ? If latest Zeiss lenses capture 700 lp mm and if we intended to understand how various

I would be happy to contribute a bit… I hope all of you have a safe, healthy, successful & wonderful 2021!! Andy schmitt

Hi :Niranjan. Sorry, I did not know these limitations to the group. I also agree with Brittonie to leave the group in its basic version. To satisfy the need of a database, when convenient I will