March 2023 – 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.