Cocktail Of Chemicals Makes This Blueprint Camera Unique

May 24, 2021 by Dan Maloney 18 Comments

When you’re looking at blueprints today, chances are pretty good that what you’re seeing is anything but blue. Most building plans, diagrams of civil engineering projects, and even design documents for consumer products never even make it to paper, let alone get rendered in old-fashioned blue-and-white like large-format prints used to produced. And we think that’s a bit of a shame.

Luckily, [Brian Haidet] longs for those days as well, so much so that he built this large-format cyanotype camera to create photographs the old-fashioned way. Naturally, this is one of those projects where expectations must be properly scaled before starting; after all, there’s a reason we don’t go around taking pictures with paper soaked in a brew of toxic chemicals. Undaunted by the chemistry, [Brian] began his journey with simple contact prints, with Sharpie-marked transparency film masking the photosensitive paper, made from potassium ferricyanide, ammonium dichromate, and ammonium iron (III) oxalate, from the UV rays of the sun. The reaction creates the deep, rich pigment Prussian Blue, contrasting nicely with the white paper once the unexposed solution is washed away.

[Brian] wanted to go beyond simple contact prints, though, and the ridiculously large camera seen in the video below is the result. It’s just a more-or-less-lightproof box with a lens on one end and a sheet of sensitized paper at the other. The effective ISO of the “film” is incredibly slow, leading to problematically long exposure times. Coupled with the distortion caused by the lens, the images are — well, let’s just say unique. They’ve got a ghostly quality for sure, and there’s a lot to be said for that Prussian Blue color.

We’ve seen cyanotype chemistry used with UV lasers before, and large-format cameras using the collodion process. And we wonder if [Brian]’s long-exposure process might be better suited to solargraphy.

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Use Blueprint Process To Print On Fabric With Lasers

December 18, 2019 by Gerrit Coetzee 11 Comments

[Shih Wei Chieh] has built a laser cyanotype printer for fabrics. You know, for art!

How do you get an inkjet head on a shoe or a couch? Most printing processes require a flat surface to print. But hearkening back to the days when a blueprint was a blueprint, a mixture of an iron salt and an acid are mixed and applied to a surface an interesting reaction occurs when the surface is exposed to UV light. The chemicals react to form, of all things, prussian blue. After the reaction occurs simply washing away the remaining chemicals leaves a stable print behind.

[Shih Wei Chieh] uses two galvanometers and a laser to cure the fabric. He uses a slightly newer process which reduces the exposure time required. This lets him print very large pictures, but also on uneven surfaces. As you can see in the video, viewable after the break, the effect is very pretty. There’s a new way to have the coolest pen plotter on the block.

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Hackaday Prize Entry: A Printer For Alternative Photography

August 24, 2016 by Brian Benchoff 27 Comments

Film photography began with a mercury-silver amalgam, and ended with strips of nitrocellulose, silver iodide, and dyes. Along the way, there were some very odd chemistries going on in the world of photography, from ferric and silver salts to the prussian blue found in Cyanotypes and blueprints.

Metal salts are fun, and for his Hackaday Prize entry, [David Brown] is building a printer for these alternative photographic processes. It’s not a dark room — it’s a laser printer designed to reproduce images with weird, strange chemistries.

Cyanotypes are made by applying potassium ferricyanide and ferric ammonium citrate to some sort of medium, usually paper or cloth. This is then exposed via UV light (i.e. the sun), and whatever isn’t exposed is washed off. Instead of the sun, [David] is using a common UV laser diode to expose his photographs. he already has the mechanics of this printer designed, and he should be able to reach his goal of 750 dpi resolution and 8-bit monochrome.

Digital photography will never go away, but there will always be a few people experimenting with light sensitive chemicals. We haven’t seen many people experiment with these strange alternative photographic processes, and anything that gets these really cool prints out into the world is great news for us.