Corn print

Yesterday I made a print that I’m very pleased with. The negative just about perfectly suited my current carbon transfer skillset and as a result, the very first print of the negative is about as good as it’s going to get. Alright, there’s a few minor issues that need ironing out, but the image is quite presentable, I think. Here it is:

Corn, August 2022. Photograph of 8×10″ carbon transfer print.

So, the good, the bad and the ugly. Starting with the ugly: there’s a warped edge to the bottom. No, this is not an artifact of the reproduction photograph; it’s actually in the print. My method of flattening prints with gummed tape turns out not to work reliably on this paper. It works fine on silver gelatin, but the tape does not adhere well enough to the final support papers I’m using. I guess I’m going to go back to simply ironing prints with a clothes iron, or putting them away underneath a stack of books, the old-fashioned way.

Then there’s the issue of the somewhat fuzzy print edges. It’s mostly visible in the top left corner, although you’ll have to enlarge the image above to really see it. Technically, it’s not really an issue, since they’re outside the image area by definition. But I prefer to matte around the black edges, retaining a little paper white inside the matte aperture, and that means that it would be cool if the edges are sharply defined. The cause of the fuzziness is type of mask I’m using when exposing these prints. I use rubylith on which I cut an appropriately sized mask, but only taking out the red film. Yes, that’s actually the way rubylith is intended to work, to the best of my knowledge.

8×10″ rubylith mask in contact printing frame. The grid lines aid in positioning the paper/tissue on top of the negative.
Corner of the 8×10″ mask; note the negative sitting on top of the mask, resulting in light piping / halation around the edge of the negative.

Now, the drawback is that the negative sits on top of the heavier transparent rubylith base, and the carbon tissue sits on top of that in turn. This means there’s a height difference between the negative and the surrounding border. With a perfectly collimated light source, this wouldn’t be much of a problem (there would still be some halation I suppose), but the light source I’m currently using is anything but collimated. It’s an old-fashioned bank of UV tubes and I expose the tissue close to the tubes, at maybe 10cm distance. To get sharper edges, there will have to be changes. Two routes come to mind:

  • 1: Switch to a more collimated light source. This had been on my mind for a while, and I have by now ordered a cheap 300W UV floodlight from China. Its wavelength is far from ideal for this process at around 395nm, but let’s see how it pans out. This was the quick & dirty, dirt-cheap option at around € 35 or so. I can’t beat that with SMD leds and driver circuitry, although I have a feeling it’s going to culminate into something like that anyway. But let’s see if the floodlight can bring some improvement and perhaps (hopefully) also bring down exposure times a bit. In any case, I’m pretty sure the experiment will give some food for thought towards a better light source, without necessarily going all-out Calvin Grier on it.

UV light source I built a few years ago. The DIY timer module I made earlier this year because I disliked the horrible user interface on the generic Chinese timer module I used before. The timer displays seconds; I might just build a light integrator instead in the near future. Note the small distance between the printing frame and the diffuse light source.
  • 2: Employ an additional height leveling mask around the negative so that the gap between the tissue and the negative remains limited. In principle a straightforward option and I might just do that next time I am bored and have some time on my hands. The trick is to find a suitable material that has the same thickness as the film I use; maybe stacking some paper would be the easy way out.

Now for the good: the good is that the bad is only the above, and nothing else. All else just works, at least for me. Contrast is what it should be and dmax is pleasingly sufficient. The detail on the print is just amazing; the center lane of the cleared path really looks like every grain of sand is right there in the print. Maybe the reduced agitation approach I used here actually works? This is a Fomapan 100 negative with ample exposure, developed as outlined in my earlier post on PVC tubes for 45 minutes, with 5 minute agitation intervals in Pyrocat HD 7.5 + 7.5 + 1000. There’s no relief on the dry print, although the surface texture is really nice to my eye, with a smooth semi-gloss. When soaked, the details stand out very nicely indeed.

Also I’m happy to note that the tissue and final support paper I prepared the other day apparently work. I’ve been reducing the pigment load to 1% w/v Talens India ink, and it seems to work just fine this way. So yes, the tissue was usable in about 24 hours and the final support in a fraction of the time; something like <5 hours.

So, attaboy. Now on to the next set of prints. I shot some beech trees yesterday and I’m curious as to how the negatives will print. They look nice enough, at least the pair I’ve already developed, so that’s promising.

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