The Big Ugly, part 4: (im)perfect present

Here we are, and this is Now. So far, I have written about the two generations of problematic and/or quasi-successful color enlarger light sources I’ve made and the lessons I’ve learned along the way. But all that is in the past. This blog is about the current, 3rd generation of the LED color light source for my (t)rusty Durst 138. It incorporates most of the lessons I learned along the way – and brought me some new ones, no doubt.

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The Big Ugly, part 3: proper SMD LEDs, but no cigar (?)

In the previous part of this series, I told about the lessons I learned by trying to use a single RGB COB LED as a light source for both RA4 and B&W enlarging. I took those lessons and gave it another go, this time using a fundamentally different approach. As the title suggests, no cigar yet – although this isn’t really accurate. The second generation device I built was actually used for a year or two before I was sufficiently annoyed by its shortcomings to replace it. So the second generation actually did work – albeit with some caveats.

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The Big Ugly, part 2: the RGB COB LED approach to color enlarging

Previously, I explained why I thought I needed a color light source and in general terms what it should be capable of. I also highlighted that it’s not so much a project with a clearly defined end (or at least, that hasn’t materialized yet), but more of a journey that continues into the present, and probably future as well. In this part, I’ll go through the phases this project has gone through. That is to say, there are really three distinct generations of the device I’ve built, and each has taught me different lessons. Before going into some details of the current (and 3rd) rendition, I’ll try to go through each generation and explain what it was/is and what its main caveats were (especially generations 1 & 2). Let’s start with the first generation I built.

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The Big Ugly, or building a LED color printing light source. Part 1: the beginnings

Previously, I bashed compound/integrated RGB LEDs such as RGB COB LEDs for the application of a color enlarger for RA4 prints. That was basically a lesson learned the hard way when building a LED-based color enlarger light source. In this series, because one post is probably not going to be enough, I’ll highlight some aspects of the system I’ve built. Or I should say: I’ve built so far, because it’s really just a prototype that will likely never be really finished. Hence the title, The Big Ugly. Because there’s one thing it isn’t, and that’s beautiful. But hey, it works! Sort of. Most of the time. Within reasonable limits. If I’m careful.

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Why RGB LEDs suck for a color RA4 enlarger

Not many people are crazy enough to build a light source for a color enlarger. From time to time, someone picks up the challenge and posts about it online. Most of the time, the concept revolves around some form of RGB LEDs, whether that be led strips, Chip-On-Board (COB) LEDs or even addressable LED ‘beads’ such as the popular WS2812. All of these are in my opinion doomed to fail miserably to produce quality RA4 prints. Let me explain why.

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