Tag Archives: Chemistry

Reliable, Total and Economical Coating and Sensitisation of Wet Collodion Glass Plates

Variously described as “historical”, “ethereal”, “otherworldly”, “alchemical”, the particular aesthetic of the wet plate continues to find use by contemporary photographers such as Sally Mann and Ben Cauchi.

The method of coating an even film of collodion on glass plates is quite an acquired skill, and by all accounts an art-form in itself: far from an exact science. Due to the necessity of keeping the plate wet to maintain sensitivity, the process was never industrialised, and each photographer produced and processed his own plates. Recently I have been meditating on the possibility of a more efficient, reliable, reproducible method of coating, sensitizing, and processing wet plates, requiring no particular skill and minimal wastage.

The method I eventually hit upon is derived from, of all things, the electronics industry. (consequently, I doubt that I would be able to patent, or otherwise claim the process) Mass-produced integrated circuits are manufactured upon silicon wafers, using a photography-related processes, called photolithography (which actually more closely resembles etching). This process necessitates the even and repeatable coating of the wafers with a photo-resist. The industrial method for accomplishing this is one called spin-coating, where the circular wafer is held level, and rotated (about the vertical axis) at a constant speed, while the liquefied emulsion is applied at the centre. So long as the rotation speed and the viscosity of the emulsion are controlled, the results are reliably consistent. The exact thickness of the emulsion is controllable, and a precise amount of emulsion maybe used.

It should be obvious how this spin-coating method might be applied to the coating, sensitisation, and processing of wet plates, to increase precision, reliability and efficiency. The apparatus need not be particularly sophisticated: reliable, repeatable results could be obtained with the re-purposed turntable, and a burette or pipettes.

But pause a moment, and consider: The traditional (hand-coated) wet-plate process itself has a particularly physical and performative quality, which lends the images an imperfect “contingency”(as Benjamin might say), and a hand-crafted kind of cachet. This leads me to wonder – having devised a method that removes much of the chance and skill from the wet-plate process – if it’s utilisation might destroy the very qualities of the process that make it interesting and desirable. Would a cleaner, more consistent, more efficient method render results that are too, in a word, industrial?

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Filed under Alternative processes, Black & White, Chemistry, Emulsions, Techniques

Thinking out loud: Ferro-gallate Printing for Photographs.

This is just something that happened to occur to me this morning, while brewing a pot of tea, of all things.

Ferric oxalate (Fe2(C2O4)3), familiar to those who have dabbled in platinum/palladium printing, is a photo-sensitive chemical that reduces to ferrous oxalate (FeC2O4) upon exposure to ultraviolet light. If ferrous oxalate were “developed” with gallic acid or a suitable,  soluble gallate salt, then the ferrous gallate (which is the key component of iron-gall ink) formed could create a dark, contrasty image.

I should point out that all this is conjecture, and practical experimentation would be needed to prove the theory.

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Filed under Alternative processes, Black & White, Chemistry, Experimentation

New, Old Photographic Processes: Practical Guides by Mike Ware

In doing some further research regarding photographic technologies (more on that to come), I noticed a resurgent trend in online articles related to older, so-called “alternative” photographic processes.

Mike Ware is a rather retro-focussed photographer (in both subject and processes) who has published significantly on the topic of what were once mainstream, archival photographic processes, which are now almost treated as novelties. In addition to his books and essays, his website also includes a kind of archive of historic processes, including detailed instructions, hints, and an awful lot of background, on a range of rediscovered photo-alchemy. It would be a great starting point for those who are curious about progressing beyond silver-gelatin.

Of course, no post on alternative photography could be complete without a mentioning the abundant resources at Alternative Photography. Here, you’ll also find in-depth information and advice, and keen enthusiasm.

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Filed under Alternative processes, Black & White, Chemistry

Round-up: DIY Film Developer Formulary

The following is essentially a list of lists. Specifically, lists of developer formulations for film.

To date, the film developer with which I’ve had the most experience is Ilford’s ID-11, or the very similar Kodak D-76: “standard issue” for a student of photography, at a time when the available range of analogue photography products is rapidly thinning. As film becomes commercially unsustainable, photographers in that medium may need to take control, and hack their own chemistry.

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Further to my earlier post on coffee-based film developmentCaffeine-Ascorbate Developers are a class of developers that you can literally make in your kitchen.

Additional linkage: Developer recipesDevelopment timesDiscussion & examples

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2012.06.25 (Mon) 23:48 · 23:48

Photographic formulas from The Frugal Photographer

Here, we have a collection of formulae from the Frugal Photographer website. At least one seems to have been lifted from The Darkroom Cookbook, Third Edition (Anchell, 2008), which is as in-depth a resource as any modern photographer could want.

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2012.06.22 (Fri) 15:16 · 15:16

Heavily caffeinated.

To anyone who knows my ongoing love affair with 1,3,7-trimethylxanthene, you may as well skip over this entry. Those cunning Costa-Ricans (specifically Saul Bolaños) have discovered a silver negative process that utilises coffee in the development process.

The obvious hook is that you have to use their proprietary “photo transfer paper”, which sounds an awful lot like a commercial process dressed in ratty hipster jeans. At least they are kind enough to inform us that it is a “silver-based” process and tell us that the magical compound in the coffee is “CAFFEIC ACID, ( 3,4-Dihydrocinnamic Acid )”.

http://www.costaricacoffeeart.com/alternative_photography_make_your_own_negative_film_or_plates.php

Also on this page, is a section on making your own silver (chloride) – gelatine emulsion (again using proprietary components), and a method for coating 35-mm glass plates for use in consumer film cameras.

I Just Wish The Web Developer Would Stop Capitalising Every Damn Thing!

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Filed under Alternative processes, Chemistry