TLF Tutorial Workshops

 Site Index 


1. The Light Farm Tutorial Workshops—Preface

December 2, 2012

These tutorials were originally posted in a series, with time gaps between lessons of several days to several weeks. This was intended to give the people following along a chance to finish each lesson before the next one. The lessons are all posted now, so someone learning emulsion making can take all the time needed. The lessons are designed to be sequential. I don't recommend dropping into "Dry Plate" without at least understanding the previous lessons. All of the recipes referenced in the tutorials are in "The Light Farm" book.

The rains beat on my studio window. The winds tear through the trees and churn up the surf to the sound of Winter that's part freight train and part rock crusher. Morning light comes late and night falls early. After a glorious summer of working with X2Ag film, the weather drove me inside. And heaven is in the darkroom.

The TLF web workshops that were parked in the corner of my brain all summer are finally coming together. If nothing untoward happens, I will start posting them soon after my holiday company leaves and the Christmas decorations are back in storage.

In the meantime, there are a couple of items that you might want to put on your list to Santa. Although most items you'll need to get started are inexpensive and readily available at Bed, Bath, and Beyond and Home Depot (and their many clones), a couple of things are specialty investments. You'll need a good scale, reliable to 0.01 gram (g), a solid contact printing frame (I like the ones made by Bostick & Sullivan), and a couple of glass rod Puddle Pushers (I mostly use the 9-inch size.) Have someone give you 50 or 100 grams of silver nitrate (tell them about Artcraft Chemicals). Silver nitrate gets cheaper and cheaper per gram the more you buy at one time. A pound costs quite a bit total, but in bulk the price per gram becomes almost cheap as these things go. I calibrate my recipes to five to six grams of AgNO3, so a 100g goes a long way.

You'll need to start pulling together a place to work—a dark'able room and a clean, dry, "studio" corner with good light. Ten years ago, I would have assumed that anyone planning to learn emulsion making would be ready to roll. I wouldn't think of making that assumption today. And I've decided that's marvelous. Starting fresh is what art is all about. Whether you are an experienced darkroom worker or just starting out: Welcome! I predict you'll be making your own printing paper, or negatives, or both, very soon.

Light Farm contributor, Wendy Monahan, will be able to give you some very valuable tips and suggestions—along with great inspiration for building a home darkroom. Her husband has been calling her MacGyver! Wendy's article is here. For our purposes, at least starting out, replace the enlarger with a contact printing light (i.e. a strong incandescent light bulb near the ceiling with a pull string on/off switch.) The tray table over the bathtub will switch out to double duty as a coating area.

If you need to start collecting chemicals, our first recipe, "T. Thorne Baker's Handmade Chloride Emulsion, TLF Adaptation", calls for silver nitrate (AgNO3), potassium chloride (KCl), photographic gelatin (available at Photographers' Formulary), Photoflo 200, and ethanol (either Everclear hooch or lab grade). My favorite places to shop online are Photographers' Formulary, Bostick & Sullivan, The Science Company, and Artcraft Chemicals.

Outside the US, there can be confusion about products with American names. To a certain extent, I expect that folks will use the internet to research products, but I do believe I have a responsibility to be as clear as possible. Clarity is always at war with brevity. There are a lot of words on the internet. I don't want to add my share of unnecessary ones, but. . . starting with "Everclear."

I use Everclear alcohol in many of the recipes I make—as did early emulsion makers. In the earliest recipes it was simply called alcohol or spirits. It was assumed that the reader had some knowledge of science and knew that the reference was to pure ethanol.

[Geek Bonus: The ending "ol" indicates that the substance is an alcohol. The syllables in front of "ol" indicate the kind of alcohol. This could be a good place to stop and run your eyes over the Wikipedia article on alcohol. Don't try to memorize it or even expect to read and understand it in the sense you would a newspaper. Just let the words you understand, and the cadence of the rest, flow through you—very much in the way you first began learning your mother tongue. Above all, don't panic! There won't be a test. It's not even remotely required in order to learn emulsion making, but I believe it will enrich your experience. This is true for any of the underlying chemistry and physics aspects of emulsion making.]

Everclear is a brand name for highly concentrated ethanol. It is almost pure alcohol and is used as a preservative, solvent, and fuel, as well as cheap booze. Because it can be dangerous, and could be used illegally, it isn't for sale in some states in the US. Each state is different. In some states, it's sold under a different brand name, though still referred to generically as Everclear. Depending on location, Everclear (or similar) is sold only in liquor stores, either openly on the shelves, or under the front counter, available only if you ask for it. In some places, it's sold in grocery stores. It is available online. In Europe, it is referred to as 95% alcohol.

The term "proof", as used in the US, can be confusing. It means twice the percentage of alcohol, i.e., 100 proof booze is actually only 50% ethanol.

Ethanol is available most places that sell lab supplies and is easy enough to order online, but be sure it's pure, without additives. Perhaps the easiest thing to do if you can't buy Everclear is to use plain vodka. 80 proof (40%) vodka is close enough to half ethanol and half water for our purposes. If a recipe calls for 100 ml water and 10 ml Everclear, reduce the water by 10 ml to 90 ml and use 20 ml vodka.

Also, the suggestion to purchase a scale "reliable to 0.01" can cause confusion. Scale specs are noted as "capacity" times "resolution," for example, "100 grams x 0.01 grams." Capacity is how big a load a scale can handle. Resolution is how small an increment of weight a particular scale is capable of measuring (as shown on its display). Does the scale say 5.1 or 5.14? It is generally agreed you need a scale that resolves one more decimal point than you want to weigh. If you really want 5.1 grams of something, it's good to know that you have 5.10 grams on the scale and not 5.14. For our purposes, things are very rarely that fussy, but silver nitrate is expensive and my time even more so. A good scale is good economics.

The rub comes with the trade-off between high capacity and high resolution. Affordable scales come one way or the other. It is cheaper to have two scales—one that is high capacity and one high resolution—than a scale that is both. My 0.01 scale only weighs to 250 grams. That's not enough to weigh a big glass beaker plus the water and chemistry at one time. Fortunately, it is no effort at all to weigh things separately and add them together.

"Accuracy" is just what it sounds like. If you want 5.10 grams, how confident are you that you really have 5.10 grams? Almost all new digital scales are capable of high accuracy. The trick is to calibrate your scale to make sure it weighs things accurately and consistently. Since calibration can get screwed up during shipping, reputable manufacturers recommend the end user preform a calibration. They often supply a calibration weight. If not, a weight (or better yet, a set of weights) is very inexpensive. The instructions will be included with your model. You set a calibration weight on the scale, and basically tell your scale what that weight weighs. You are educating your scale to weigh everything else against a known standard. It is suggested you calibrate frequently.

A question often comes up about contact printing frames. Is it necessary to have one? No, they are a convenience and an easy way to make a good quality print. The idea is to press the emulsions of a piece of film and a piece of paper really tightly together during exposure. A contact printing frame does that quickly and reliably. You can accomplish the same thing by making an "exposure sandwich" with a thick'ish, heavy sheet of glass, a piece of black felt a little bit bigger than your paper, the paper (emulsion-side up, the negative (emulsion-side down), topped by another thick'ish, heavy sheet of glass. The assembly is weighted down at the corners or clamped together. When we start learning about coating, I'm going to suggest that you get 5 or 10 sheets of 13"x 20"x ¼" glass. I have ten sheets that I couldn't do without. Two of them would be perfect for a contact printing sandwich.

Copyright © The Light Farm