photography – Koraks tinkers

Collimated vs. diffuse light – a cyanotype example

On a forum, someone asked how to get their cyanotypes made with 3D objects instead of a negative crisper. The fundamental issue at work here is how collimated or diffuse the light source is. Here’s a quick example of the difference between both.

Kind of blue – A test with UV LEDs for DAS carbon transfer

So the 400nm LEDs I had been using since October or so worked really nice for dichromate carbon transfer, but I ran into trouble with DAS carbon with them. Some further testing with my bank of trusted Philips BL tubes and a little theoretical exercise suggested that at least some 365nm exposure is needed to get DAS carbon to harden reliably especially in the highlights. So I’ve been testing a bit with 365nm LED options – two in particular that seemed attractive. This is a small report on these tests.

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!

Fixing Sekonic L-358 and NP spot meter wrong readings

Years ago I picked up a second-hand Sekonic L-358 and have used it ever since with great pleasure. One of those things you just turn on and it works – provided you feed it a new battery once every few years or so. Recently, I got a 5 degree ‘NP Finder’ for it, which turns this incident light meter into a proper spot meter. However, today I ran into a disconcerting problem: totally wrong meter readings. What’s up with that? And can it be fixed?

Composition target practice

Despite all the technical stuff I write on this blog, my interest remains mostly in photography, and by extension, printing. I don’t often show what I make, but I’m going to try to break that pattern. This entry will be about composition – a subject that’s evidently important, but I admit having difficulty dealing with it much of the time. Practice hopefully helps, at least in part.

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.

DAS right! – Solving the teething problems of DAS carbon transfer

Previously I wrote about trouble I was running into with DAS-incorporated carbon tissue. I just couldn’t get those tissues to transfer properly. Well, looks like I figured out why. In the process, I received some useful advice to boot, and perhaps there are some myths being established as well. Are you starting out with DAS and running into issues? Maybe some of the info in this blog can be of help.

Color carbon made feasible, part 1: halftone screens

In my previous blog post, I outlined a couple of tough challenges I met in the color carbon project. These challenges are partly inherent to the carbon transfer process, and partly stem from working with digital negatives, in particular continuous tone negatives. In this blog, I will outline the two main components to a solution to these challenges: halftone screen negatives and sensitizer-incorporated tissue.