OK, basically I was wondering if it was possible to make large cyanotype prints
with a video projector. If you've been wondering the same thing keep watching...
Discovered in the mid-1800s, the cyanotype is a flexible, affordable,
and accessible way of making photographic images. Let's ask Wally Wikipedia for a brief description.
Cyanotype is a photographic printing process that produces a cyan-blue print.
Engineers used the process well into the 20th century as a simple and low-cost process to
produce copies of drawings referred to as blueprints. The process uses two chemicals;
ferric ammonium citrate and potassium ferrocyanide.
I have the Photographer's Formulary cyanotype kit, which comes with 500mL bottles of each chemical.
You basically just mix these together in equal parts to create your photosensitive solution.
This can be brushed onto a heavy card like watercolor paper or bristol board.
You can even use fabrics like canvas.
Cyanotype requires UV light to expose, and a lot of it, so this prep can be safely done
in just a dimly lit room. You'll want to find somewhere dark to let it dry,
which should only take about an hour or two.
OK, you're ready to go, so now what? You could just take some physical objects and put them on
the paper and make a photogram, but that isn't what we're here for. We want to make prints.
The most common method is to take a picture, invert it, and print it out onto a transparency.
With this you can lay it directly on the sheet and make a contact print.
But that involves making a print to make a print, and I don't want to do that. Also,
I'd be limited to the size of my printer, and I want to go bigger. That's when I realized - hey,
I have an old DLP projector. Now, it doesn't have the resolution to make a super sharp print
as it's only 800 by 600 pixels, but it can go as big as I want - which is a trade-off
I'm willing to make - especially in the name of science. My main concern: can the lamp
kick out enough UV to expose the cyanotype, well, there's only one way to find that out.
Here's a negative of a photo I took back in the spring with my Mamiya 23 medium format camera,
check out the video I made on that one. After tweaking the contrast I taped my
coated sheet to the wall and went for it. To my surprise, after just a few minutes I
could see that something was happening. I left it running for 90 minutes total.
I didn't expect this to be enough time, but I still wanted to see what it got me.
I rinsed it off in the bathtub and hung it's dry. Yeah, that's how you develop a
cyanotype - you just rinse it off in water. Hey Wally, tell the folks what's happening here...
The water-soluble iron(III) salts are washed away. The parts that were exposed to
ultraviolet turn blue as the non-water soluble Prussian Blue pigment remains in the paper.
Obviously I didn't expose this enough and the density of my negative seemed to be off,
so I tried another print with a lower contrast and longer exposure time. After two hours and
15 minutes, I ended up with this print. A much better result, but still room for improvement.
For the next round of prints I went a little bit smaller. I exposed this one for three hours
and did another for four. This definitely turned out much better. Maybe I'll use it as a thumbnail.
In conclusion; this is a relatively easy way of making very large prints.
Of course, when you get up close you can see the individual pixels, but I still think it's kind of
cool. Now, if you aren't the biggest fan of the blue, cyanotypes can be toned using things like
tea and coffee, but I think that's pretty good topic for another video. Regardless,
if you've ever wondered if it's possible to expose cyanotype with a video projector,
well, the answer is yes. Note, I used a DLP projector and I'm going to assume that the
differences between types of projectors and their lamps will have an effect on
the amount of UV that is emitted. But, with how cheap the chemistry is, it's worth a try.
Thanks for watching, if you have any questions please leave them below.
I'd really appreciate it if you subscribe to the channel and I hope to see you in the next video.