- A cylinder is not a plane, but you know what I mean. Alternately, we simply have to postulate a suitable geometry, and the two are equivalent anyway.
- About 0.24mm in diameter.
The simplest possible camera.
This is an anamorphic pinhole camera made out of a film canister, a piece from a can of root beer, some glue, and black paint. I used it to take this picture.
What the diagram above attempts to show is that the film rests against the wall of the canister, in a cylinder parallel to the optical axis (in a normal camera, it's flat and perpendicular). Where in a normal camera you have a field of view shaped essentially like a cone, in this arrangement the centre of the cone is invisible. I've tried to show what this looks like on a picture of the original scene.
There's also a significant amount of distortion, from a couple of different sources. First, the focal length varies with the height of the film; in this case it's around 19mm at the top of the film, and about 50mm at the bottom. Unwrapping the cylinder to view the picture certainly doesn't make it any simpler, either.
Because the f-number depends on the focal length, it varies over the height of the film as well; from around f/80 at the top of the film to f/210 at the bottom. That sounds like a dramatic difference when you're used to values around 2.8-16, but it's really only about 1.5 stops.
Comments and faves
matt (63 months ago | reply)
I figured it might help to be able to look at both the images on the same page. This is (approximately) the field of view of the camera, though there's still some geometric trickery involved (that I try to describe there).
effixe (63 months ago | reply)
yeah! welcome to the great world of anamorphs.
Is it a one shot cam? or you can load a spool?
matt (63 months ago | reply)
Just one shot. This was just a quick try before moving to something bigger that will require me to purchase some tools. Though given its size, I may keep one or two loaded in my photography bag.
Hani Amir (63 months ago | reply)
*is very confused*
I'll have to try and get my head around this later o_O
easyaction (63 months ago | reply)
au contraire....
this is definitely a cut above the simplest possible camera
light years ahead even
:-))
easyaction (63 months ago | reply)
yo dude!
if you're having trouble getting your head around the geometry of this camera:
first up, try getting a cardboard cylinder, cut a window out of the side and tape over one end... then look into the open end and out thru the window. you will now be seeing what the pinhole camera is seeing.
the other exercise is to print out an anamorphic image and roll it up with the image on the inside of the roll and when you look at it the curves and bends will be magically straightened out
keep in touch!
End red China's shameful occupation of Tibet [deleted] (63 months ago | reply)
I think you have shown this in a beautiful way. Most excellent!
--
Seen in your Anamorphic Pinhole set. (?)
dodob19 added this photo to his favorites. (58 months ago)
HoneyB12 [deleted] (57 months ago | reply)
This is so cool. I love the effect. It's very generous of you to share your knowledge.
mzv (53 months ago | reply)
i have a difficult time understanding why the pinhole is not parallel to the film plane. could you explain it? seems a bit counter intuitive. and how is that accounted for when metering for exposure length?
mzv added this photo to his favorites. (53 months ago)
easyaction (53 months ago | reply)
the film plane is skew to introduce distortion to the image !!!
www.flickr.com/photos/matt/2348292323/
Quo Est Demonstratum !!!
matt (53 months ago | reply)
@mzv: easyaction describes the why (at least without getting metaphysical about it), and there's a lengthy explanation of the optics and exposure that basically boils down to this: calculate the f-stop using the distance from the pinhole to the centre of the film, and expose as normal for that value. There's some variation over the film (see the link), but it's comparable to the cos-4 falloff for normal film planes; in other words, not usually that big a deal.
harianabito, Mark.Doxey, G-AtA, Paolo Grazioli, and 4 other people added this photo to their favorites.