RA4 – Koraks tinkers

Creative RA4 – Bleach and redevelop

Straight printing on RA4 paper is great fun and it’s what I do most of the time when I print color in the darkroom. But the RA4 process has several tricks up its sleeve. The other day I decided to revisit one of those tricks I had played with briefly some years ago: bleach and redevelop. Here’s an example of what it does and how it’s a useful took in boosting print contrast without saturation going overboard.

A round roll in a square box – Cutting RA4 color paper sheets from roll

When I started out color printing on RA4 paper, I bought a couple of boxes of paper from a retailer that offered a cut-sheet option. But sadly, they didn’t offer the papers I really wanted to try, and I also found that buying rolls of paper is far more economical. The only thing is – I had to figure out a way to cut sheets from a roll of paper. In the dark. Turns out it’s not that difficult at all!

Pixels, not grains – Why RA4 paper is ‘digital’, and why this matters (not?)

Look at the back print of some papers, such as FUJIFILM’s Crystal Archive Supreme HD, and the word ‘digital’ features prominently. Indeed, I’ve been told that current Fuji RA4 color papers are exclusively intended for digital exposure. But does that mean we can’t use them anymore for optical enlargements?

Between the lines – The importance of interlayers in RA4 color paper

‘Today I learned’…a lot, in fact! More than enough to fill a couple of blogs, but let’s start with this one. Did you know that color paper has layers that you can’t see, that are actually designed to be invisible, but that play a huge role in the visual aspects of the paper and the images on it? Well, now you do! They’re the interlayers, and they are quite essential, as it turns out. I’ll try to explain.

Color me purple – Some color developer formulas including C41 and RA4

Despite the modest resurgence of interest in film photography, supply issues remain a concern. This is nothing new; a few years ago, I already worried about this and figured that I wanted to expand my options when it came to in particular color chemistry for C41 negative development and RA4 printing. I started collecting formulas I found online, purchased the necessary chemistry and mixed quite a bit of (mostly) developers myself. Now seems a good time to share my findings with you. If anything, it might be convenient to have some key formulas in one place.

Roll another one…modifying the Durst RCP20 for RA4 processing

Sometimes I’m just incredibly lucky. Tabletop RA4 roller transport processors are unobtanium these days and if you find one, it is likely to be insanely expensive. I happened across a Durst RCP20 (which in fact is a Thermaphot machine, but Durst sold them under their own brand). These machines have a few drawbacks though, which boil down to them being darn old pieces of equipment. First and foremost, to be able to use mine, I had to convert it to run at the right speed for the current RA4 color paper process. Here’s how I did this.

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.

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.

Some light to the darkroom

What’s the essence of a darkroom? That’s right – light! Seriously though, I think good light makes all the difference in darkroom work. First and foremost, it’s just pleasant to have ample and good-quality light to work with. But it’s also essential for judging print quality and properties such as hue/color balance, toning etc. In this post, I’m showcasing my current darkroom lighting setup and I will also discuss some lessons learned and loose ends/issues.