Pinhole/Cyanotype

Hi folks;

Just a quick question while I try some experiments here... Has anyone had

experience/success in combining pinhole photography with the cyanotype process?

I imagine it must work, though the exposures might be astronomically long. Given

that a contact print "new" cyanotype prints out in 2-3 minutes in full sun, how

would you calculate exposure times for pinholes? (I have calculated that for the

dimensions I am using for my experiments that the optimal pinhole for

conventional paper is ~.75mm)

Any tips would be greatly appreciated.

Thanks,

__________________

Tom, on Point Pelee, Canada

When all is said and done, more is usually said than done.

(((((smile)))))

Hi Tom.

Are you familiar with the website mrpinhole.com?

[ I, too, have been experimenting with "solar print" paper, aka cyanotypic paper. With

post-processing in PSCS3, I have gotten some very pleasing results. For example, see

---> http://www.photo.net/bboard-uploads/00MJSc-38086784.jpg ]

If I were to use the smallest size paper I have as film, 140x195mm, a pinhole of 0.65mm

would "cover" the "negative." It would have a "focal length" of 240mm and an "f-stop" of

367.

Exposure will be a "guesstimate" and would have to be refined by the results of

experiment. A cyanotype contact sheet needs 2-3 minutes in full sun for exposure. So,

using MrPinhole's exposure guide for f/367,

---> http://www.mrpinhole.com/exposure.php?Fstop=367

a 2+ minute exposure corresponds to almost 612 hours! As I would find 612 hours to be

an impractical starting place, I would first try an entire sunny day. So, using a tripod, or

some other fixed attachment, I would point the pinhole at a landscape, for example, and

walk away. It may, or may not, result in an image.

I would be interested in your results. Good luck!

Johnny

Thanks, Johnny;

Between www.mrpinhole.com and www.pinhole.cz I have pretty much come up with the numbers I need. According to my figures, with a pinhole of .75mm, I will be working with an aperture of f373. Peanuts, I say! :)

I got my test ready to go before bed last night. (about 3:00 AM... don't ask) and woke to about four hours of rain this morning. By the time I moved my setup outdoors, it was about 10:30 AM. It's mostly clear, so I'll let it sit for most of the day and see what I get.

Thanks again,

__________________

Tom, on Point Pelee, Canada

When all is said and done, more is usually said than done.