Monday, July 18, 2011

The Taco Method

With such a dirty sounding name it's got to be good, right? Yeah, it is.

The taco method has kept me shooting 4x5. Not that it does anything above and beyond normal processing, but it allows me to process sheet film in my kitchen...without becoming drunk on rage-ohol.

Let me back up a bit. I was lucky enough to score my 4x5 camera off of craigslist on the cheap. But I lacked the infrastructure to support a sheet film workflow. I had a variety of tanks for roll film but was struggling with sheet film options. The purists will tell you that the only way to develop 4x5 is tray developing. It's great that you can either do a whole stack at once or individual sheets to n+1 if you're into the whole zone thing. The biggest requirement is a darkroom. Sad face. I have no darkroom or any significant space that can be totally blacked out. If I tried hard enough, I could probably get my bathroom dark enough, but I'm not huge on the idea developing on my hands and knees with a bunch of trays in my bathtub.

So I opted for a 4x5 daylight tank. The cheap one. Extra sad face. Yeah, it was the Yankee 4x5 Agitank. Notorious for being a shitbox and proven first hand. Where to begin...build construction, awkwardness of loading sheets, less-than-attached lid, ridiculous amount of chemistry to fill? No, lets go with horrific uneven development. Sheet after sheet showed the same streak down the left side.



Uneven development from the Yankee Agitank.
I worked through all the possibilities until the only possible cause was the developing tank. Thankfully, the internets confirmed my suspicions with similar horror stories from other Yankee film tank victims.

Since I didn't want to spend about $75 on an HP Combi-Plan tank, which is supposed to work fine, I was open to suggestion. Thankfully, I found this post on Flickr. I already had a 2-reel tank, so why not give it a try. Many many sheets later and I've yet to encounter a single problem.

 So the basic idea is to curl your 4x5 sheets, secure them with a hair band, fit them into a 4x5 tank and process just as though you were doing roll film on spirals.

The film is curled emulsion side in, so that it doesn't come into contact with anything. It's perfectly fine for the base material to touch the sides of the tank.




Found at Target, Walmart, etc.
To keep the film curled, I've had excellent results with the pictured hair bands. They're just stretchy enough to securely hold the film and the fabric coating allows the chemicals to come into contact with all of the film surface (apparently helps with removal of the anti-halation layer).

The bands come in at least two different thicknesses. I originally started with the thicker bands (with good results) but have now found the thinner bands to be much better to work with. They're not as tight on the film as the thicker bands, there is less surface in contact with the film and for the same price you get 50 instead of 24.

4x5 taco'ed - emulsion side in.
I only use the bands once and then discard. I doubt it would make much of a difference to reuse them, but I'm paranoid about chemical carryover from a previous batch. Although, who knows what chemicals leach out of the bands from the manufacturing process. What I know is using them once works fine and they're cheap enough that I don't feel bad about one-shotting them. (It has become fairly scripted that when I buy them, the cashier says, "oh, are these for you?" Which is a valid question since my hair is quite long and could be worn in a ponytail should I choose. But I don't. Like clockwork I fumble out some explanation that yes, they are for me but not for my hair. Puzzled looks ensue. Then I start babbling about film developing and chemicals and tacos and I can tell from the look on the cashier's face that I'm not the only one who wished this conversation had never started.)

No film was harmed in the making of this.
I can fit a maximum of four sheets in my 2-reel tank of choice. Pro-tip: Always put the center column in the tank when you're developing. A light-proof tank is not light-proof sans column. Besides, it helps keep everything in place during agitation.

Before trying this for real in my changing bag, I practiced a few times with my experimentin' sheets (I have yet to buy a film holder that hasn't coming with at least one random sheet) in daylight. Then I tried loading them in the dark. The first few attempts were not pretty, so I definitely recommend getting a feel for it.

The other thing to note is how much chemistry it takes to fill the tank. You need to figure out a volume that makes certain the film is covered. For my tank it takes 32 oz. I imagine most other tanks are similar.

I've now processed dozens of sheets of both black and white and E6 with the taco method without a single problem. A huge improvement over the 100% failure rate of the Yankee tank. There are other tanks out there for 4x5 that probably work fine. There's also this neat contraption that I've heard good things about and may try in the future, since I already have the proper size Patterson tank for it. And if I ever get a proper darkroom I might rock some tray developing, but for now taco does it for me.

1 comment:

  1. "It has become fairly scripted that when I buy them, the cashier says, "oh, are these for you?" Which is a valid question since my hair is quite long and could be worn in a ponytail should I choose."

    At least you're not buying them at Radio Shack...

    On my penultimate visit I was hit with the usual "What are you working on?" and politely replied with "I don't want to get into it. Don't be offended." I don't know what irritated this guy more - that fact that I wouldn't share details of my project or that not doing so gave him no foundation from which to offer poor advice.

    On my last (and I do mean last) trip to Radio Shack I was hit with the same question. I told the guy I was building a bomb and asked him for a 6V lantern battery.

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