It all started last year, when I discovered Photojojo - a new online photography newsletter, and subscribed to it. Filled up with fun snippets about photography, DIY and photographers and etc, I discovered - more than a year later – An article about pinhole photography.
That led me to a website where they showcased all sorts of bizarre pinhole cameras, which in turn led me to the HEXOMNISCOPE!
From their website:
"The long awaited very rare limited quantity all metal Hexomnisope pinhole camera which has 6 pinholes and 6 individually operated shutters around its circumference to make 6 overlapping 60 degree images onto 120 film. Shutters can be turned on and off independently, but have a single release. 4 complete images of 6 pinholes each can be made on a roll of 120 film. Pinhole diameter is 0.0055 inch for an f stop of f180. All handmade. A very sophisticated design by Matt Abelson. Made to perfection! You will be amazed at the craftsmanship of this absolutely wonderful new camera. It is approximately 5 inches high and 5 inches in diameter. Weighs almost 3 pounds. 120 film winds around inside cylinder. The Hexomniscope is only available from the Pinhole Resource. Comes with an instruction CD giving clear instructions for use and exposure guide. Designed and made by Abelson Scope Works."
So I want one, but priced at a little over $1500, and as my story usually goes, I don’t have the necessary spare parts to buy it … So following my usual story and script, I think of making it to my own silly specifications.
The hexomniscope is developed for 120 format film. I've used that format only once, so decided to make a 35mm film paper version for the same.
The f stop of a pinhole is calculated by determining the size of the hole and the focal length (distance from the pinhole to the film). So a camera with a 0.5 mm diameter pinhole, and a 50 mm focal length would have an f-stop of 50/0.5, or f/100. Others are even higher, up to f/360. It all depends on the size of the hole.
From that and this - http://www.mrpinhole.com/calcpinh.php; I get :
IF and only IF:
focal length = 40 mm
pinhole dia = 0.25 mm,
THEN and only THEN:
f stop is f/160
if ISO = 100, 35 mm film
image dia = 76.8 mm
angle of view = 40
Similarly:
focal length = 25 mm
pinhole dia = 0.25 mm,
f stop is f/100
if ISO = 100, 35 mm film
image dia = 48 mm
angle of view = 70
Damn pinhole!
My hexomniscope will look a little different, since its for 35 mm film. It will be shorter. Around 5 cms in height.
The only other time I have tried pinhole is with my dSLR and a pinhole disc in place of the lens. Works wonders! Now hoping this works wonders too…
Hey meghna, this f-stop thing has always confused me. And it still does.
ReplyDeleteyou said, "f stop of a pinhole is calculated by determining the size of the hole and the focal length" But you say that's "(distance from the pinhole to the film)" And my photography teacher had also told me the aperture is ratio of diameter of the hole to the distance from hole to film. But does that relate to the focal length of the lens at all? Because depending on different cameras and lens combination, the plane of film or sensor is further or closer to the aperture/lens. Like the Olympus E-P1 camera because it doesn't have a miror box, sensor is closer to the lens/aperture.
Uh.. even I don't know where I was going with this now... but just wanted to get it out of my system.
Yes, its damn confusing for me too... who ever invented that term meant for it to confuse us!
ReplyDeleteBut i guess every camera has a different f stop... (I don't know really...)