Decisive Momentum

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 dissolv...

As I explore a photographic process, I will post brief summaries of its essential technical elements. These summaries are not meant to be comprehensive or to substitute for books that deal in-depth with these processes. They are more field notes for myself and might be useful for a quick lookup while working with these processes. Remember that many of these alternative processes have been around for a century and a half and more and they have evolved considerably over that time. Remember, too, that these processes were not originally meant to be used with silver or even digitally printed negatives as most modern practitioners of alternative photo processes do. There are endless variations of formulas and techniques rather than one simple "right" method as my quick overview might imply to the superficial observer. But hopefully these summaries will serve as a quick reference or encourage you to read and explore further. Cyanotype from 4x5 negative. Tinted using tea. H...

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...

For a little background to these overviews, see here . History: First introduced by Louis-Desiree Blanquart-Evrard in 1850, albumen printing was the dominant photographic process for most of the second half of the nineteenth century. Negatives: A density range of 2.0 to 2.5 is good. Preparing the albumen: 500ml of egg whites (no yolk or white stringy bits) + 1ml glacial acetic acid + 15gm ammonium chloride + 15ml distilled water. Stir briskly until it turns into a froth. Cover container and refrigerate for 24 hrs. Remove the froth on the top and filter the liquid through cheesecloth. Age in refrigerator for a week or more. Coating the paper: Coat by floating for 3 mins and hang to dry. To double coat, the albumen needs to be hardened. This can be done by steaming, heating to about 150F with a hot iron under a protective board, or dipping in a 500ml 70% isopropyl alcohol + 15gm ammonium chloride bath. Sensitizing the paper: Either float, brush or use glass rod to coat with 12% silve...

An old friend just asked me for a film recommendation. She got a DSLR recently, made a few nice photographs, converted a few to black and white, got to wondering what real black and white film is like, dug out an old family Minolta SLR - and here we are. I thought that a lot of people who have started out with digital photography and never experienced film might be in a similar position. The terminology surrounding various types of films, formats and processes can be a little confusing and daunting - it was for me when I started, even though it was before digital photography exploded on the scene. So here's a quick rundown for the rank newcomer to film. Any advanced photographer will, of course, find this full of generalizations and simplifications, and the beginner should note that the techniques surrounding film photography are a vast subject. It ranges from the extremely precise to the seemingly mystical but is always fascinating. I hope you will find this little write-up an ade...