Isn’t the Zone VI Type II a cold light head?Originally Posted by Michael R
Roger
Isn’t the Zone VI Type II a cold light head?
Roger
Sorry about that. I forgot Neil indicated his current light source is no longer functioning so my question didn’t make much sense.
My incandescent head is a Beseler 45s. My interest is in enlarging 5x7, and I happen to gave a Type II, non-functional Zone VI head. I have a Type II 8x10 adapter and head that would work of course, but I've been thinking about selling it. Alas, I may need to keep it a bit longer.
Thanks for bringing this thread to my attention. I'll have give it some study.
At the risk of being called a miser and naysayer, I can't resist but remark that this approach will work OK for B&W, but not so well for color. I've been down that road and my conclusion is that addressable 8-bit LEDs like WS2812 etc. are not optimally suited for color work. I've explained this here: https://tinker.koraks.nl/photography...-ra4-enlarger/ The problem in my view is (1) the actual color of the LEDs used and (2) the 8-bit address depth that's insufficient for decent filtering options. Again, for B&W it'll likely work fine.
I built a variable contrast LED head and controller about a decade ago for my Durst 138. I’m redesigning it now with the idea of a more modular system that will also do color, since I have started shooting color 5x7 and my color head tops out at 5x5. This could also replace my existing VC head if I decide to only have one enlarger in the darkroom.
I will document this as it gets farther along, but the idea is to try to use as many off the shelf parts as possible so others with less comfort in electronics can make this as well. I’m thinking of 6” wide MakersLED heat sink https://www.ledsupply.com/led-heatsi...d-heatsink-kit with common LDD-H drivers, LEDs on stars again, and my own controller design. The controller will be spit with one simple controller that just sets the brightness per channel and switches the light on and off. That will accept various inputs such as a a calibrated controller like my current f stop based one or just a voltage sensor to use any existing timer.
I should add the the MakersLED full line also has a controller and driver setup that might work as an off the shelf setup, but I haven’t tested it.
There has been some discussion of using Artograph light boxes as a cheap alternative light source.
https://www.artograph.com/light-boxes/
I thought perhaps it might be worthwhile posting a picture of my light box in case it is of use to anyone. Makes uniformity much easier. In fact the only reasons I have any diffusers on it are to create a "screen" and for attenuation.
I converted my Beseler 45 MCRX to LED Diffusion a few years ago. The final build was RGB plus white for focusing. 50% of the power used is waste heat but the LED "stars" are thermally mounted to a massive heat sink and it barely gets warm. Better than tungsten bulbs which have about 95% waste heat. With LED I could leave out the normal IR absorbing glass. Here are some pictures.
The head was built for B&W Split Printing with Multigrade paper. Blue and green can be exposed separately or together. The diffusion virtually eliminates dust and scratches as well as providing a better highlight range.
In the past 20 days I had to make an enlarger for all 9x12 and 10x12,5
found a Burke & James 13x18 field camera in so -so condition cleaned it up an put a cold light flat light 17x17cm NOTE: the next light head will be 25x25 to do 13x18 up to 20x25 cm.
It is work in progress with all the problems and qurkes popping up.
the point is the cold flat light with no heat, and the thin composition.
Most interesting a bit to complex [for me] exellent Mal Paso.
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