I noticed more viewers are looking at this section than DIY. So I posted here.
This is sort of DIY, but really it is just cutting a piece of foam core and laying a light source on top of it. No work involved.
See this link for my 5x7 version which is fancier but no better.
In the above thread I used a http://www.artograph.com/lightboxes/lightpad-920/ which works great and uses 4.6 watts at 120 vac. Operates at 5 degrees F above ambient. Which means no heat, no negative heat warp. Even after hours of usage, it never gets hot.
This 8x10 version uses the next size bigger, http://www.artograph.com/lightboxes/lightpad-930/ It also works great and uses a proportionally greater amount of power, clocking in at a whopping 7.4 watts at 120 vac. Exactly the same characteristics. 5 degrees F delta +.
The head's construction is very simple. I cut a 2 pieces of 3/16 black foam core to 15x17, glued them together and cut a 8x10 window in the right place, which is above lens center.
Then I just stacked the light box on top of the foam core, on top of the enlarger. Gravity works! I did gaff tape the power wire down so I don't pull the $117.00 light box off when raising the head.
Very tiny light leaks, which are easily sealed with gaff tape.
If anything, I have too much light at F8 with my 250mm Kodak Ektanon enlarging lens. I may add additional diffusion to lengthen printing times.. Focus is very bright. mine is installed on 10x10 Calumet enlarger chassis, that formerly used a Super ChroMega F Dichro II 1000 watt head.
As with the 5x7, I have a glass-less film carrier for 8x10 as seen in the pics. I bought it from a member here. I also have the traditional double glass carriers with one AN plate. But I prefer glass-less.
Obviously I cannot guarantee you will have the same results or even like my solution, I offer this up only as an idea. However, an idea I use. I do recommend you use only the above brand light pads, as I have tryed other brands that are not good. I have no connection with Artogragh. I bought mine on Amazon and have seen widely ranging prices, most likely depending upon school schedules.
I think one thing that makes these light pads work is the LED's are mounted evenly about the perimeter and the film size for each light pad is centered and away from the edges, allowing for even light.
If these light sources prove slightly uneven, I propose making an inkjet digital graduated ND diffusion filter/mask to even the light pattern, but I think that is unnecessary. I have posted proof of concept prints on the 5x7 thread and will be doing the same with this setup soon.
Another thing, I have noticed a one second delay in light on, but the LED is up to full strength right away, and the delay is consistent.
Lastly, Amazon will take it back if you don't like it. Try that with a used 8x10 head. I already threw my all boxes away...
Reply With Quote
Bookmarks