Van Dyke Prints: An Overview

Van Dyke print on handmade paper from 4x5 negative

For a little background to these overviews, see here.

History: Introduced in 1889 by Arndt and Troos, the Van Dyke print is part of a group of iron based processes which draw on Sir John Herschel's work on the Argentotype silver-iron process developed in 1842.

Negatives: A density range of about 1.5 is suitable.

Sensitizer: Part A: 9gms ferric ammonium citrate (green) + 35ml water
Part B: 1.5gms of tartaric acid + 35ml water
Part C: 12gms silver nitrate + 35ml water
In moderate light mix A, B and C (in that order) and age for a few days before use. The solution keeps well for about a year if kept in a cool, dark place. At times, owing to trace chemicals in various supplies of ferric ammonium citrate, the sensitizer may develop a muddy precipitate after about 2/3 of solution C is mixed. This can be allowed to settle and the clear sensitizer on top used, or adding about 2.5 gms more of tartaric acid can also dissolve the precipitate. The additional tartaric acid results in a fainter or no print-out image, but the developed image looks fine.

Contrast control: Contrast control can be achieved by (a) using ferric citrate in varying proportions in Part A of the sensitizer, (b) by adding about 10 drops of a 10% solution of potassium or ammonium dichromate to 500ml of the second bath during washing. (c) printing in diffused light (with perhaps a burst of direct light at the end) also subtly affects contrast. Refer to Christopher James' book for details.

Coating the paper: Use a glass rod or hake brush to coat the paper. Once the sensitizer sets, further coats can show up as streaks, so quick coating is helpful.

Printing: Print until the image appears about a stop darker than you want the final result.

Processing: (1) Wash in distilled water or tap water with a pinch of citric acid added for 5 mins. (2)Wash in running water for two mins. (Can be toned after this point). (3) Fix in 3% sodium thiosulfate solution with .2% sodium carbonate (washing soda) for about a minute, (4) followed by a final wash in running water for 30 minutes. Hang to dry. Ironing the print with a hot iron can increase the contrast slightly and change the color.

Leica 40mm Summicron-C vs. CV 40mm Nokton

So, I was getting bored working at home but didn't have the time to go out to do any meaningful photography. So I decided to do the next best thing - some meaningless photography! a.k.a. lens tests. Since I had newly acquired a Leitz 40mm f2 Summicron-C, I decided to find out how my usual street lens, a Cosina-Voigtlander 40mm f1.4 Nokton MC, matched up against it. So I drew up a plan and shot off a roll of film and here are my findings. I tested for the factors that I find important in how I use these lenses - i.e. handheld street photography. Of course, all the standard caveats of informal testing of photographic equipment apply - sample variation, non-objective criteria, do-your-own-testing yada yada - but I hope you still find the review interesting. Camera was a Bessa-T, with TMax 100 film at EI 64 developed for 6.5 mins in HC110B (.1 - 1.35 density range). Everything scanned with a Nikon Coolscan IV at 2900 dpi. Minimal or no postprocessing applied. Where I have applied even...

Metering by Eye

Light is the basic element of photography, just as sound is that of music. A good photographer should be as familiar with light as the good musician is with notes and scales. Photography is, at its core, based on a very simple principle. An image of the world is captured by allowing a certain amount of light to fall on a piece of photosensitive material. Whether the photosensitive material in question is a silicon chip, silver film, glass plate or salted paper, this elegant little concept holds. Whether or not the light is shaped by the latest cutting edge in glass and coating technology, an old brass lens or indeed a humble pinhole, the same principles apply. The crucial questions of how much light reaches the photosensitive material and in what ways that amount may be controlled go to the very essence of photographic technique – the determination of exposure. “Reading the light” or “metering by eye” can be easily mastered with a little practice, yet most photographers leave this c...

Using a DSLR as a Shutter-Tester

What good is a DSLR if you can't test the shutter of your Holga with it? Ok, I'm kidding, but there is a fairly simple way to use a DSLR as a shutter speed tester for any lens that has a leaf shutter. In fact, with a little care, this method can be used to test practically any shutter. Don't expect pinpoint accuracy or rush to put your lab equipment on eBay, but this method should be accurate to within at least a third of a stop - certainly good enough for average everyday use. Think for a moment what a shutter does. It is simply a way to block the path of light falling on the film/sensor and then to remove that blockage for a certain known amount of time to let light fall on the film/sensor. It's a pretty simple concept really - a mechanized and repeatable version of the old hat-on-lens technique. Problem is, shutter speeds go off - they slow down, they speed up and do all sorts of funny things. Often, as in the case of mechanical marvels like the Holga, they are simpl...

Decisive Momentum

Search This Blog