1. Paint the inside of your can flat black.

2. If your lid is opaque, you are fine, if not either paint it or tape it until it is opaque.

3. Measure your focal length to determine your pinhole size. Measure from your pinhole to the center of your film. (see diagram)

4. Place your pinhole on the inside of the lid.

5. Go shoot a photo w/ your new camera.

6. Post your results in the Anamorphs section of Flickr.

Good Luck. Feel free to email me w/ any questions.

Pete of Casperelectronics is gearing up for the execution of his original idea to have a collective book of bends to be published and distributed at the upcomming Bent Festivals in 2007. With only 2 months to spare everyone is encouraged to submit up to 3 entrees to be considered for the publications in this edition of the book. A really cool idea expecially if your name gets printed and you can point to it and be like, ” Yeah, thats me! I totally found that bend!”

More Information is located in Pete’s website.

His post was the answer to a question posed regarding the mounting of a Pinhole. The opening “in front” of the pinhole is sometimes overlooked when people start building cameras. That is, until you expose your film/paper and find that you have vignetting around the edges. Unless this hasn’t happened or you haven’t read about it the thought may never occur to you.

So taking the opeing size into consideration, a question comes up. “What should the size of an opening be? Of course you can go really large to be safe, but there must be a way to figure out exactly how much clearance is really needed.

Well thanks to Joe’s post, I have been enlightened. Here it is:

Terminology:
“Projection Distance” = distance from pinhole to center of film
“Film Width” = width of film at its widest point
“Film Height” = height of film at it tallest point
“Front Thickness” = thickness of front of camera (including shutter mechanism) in front of pinhole aperture

Therefore:
Front Opening Width = (Film Width/Projection Distance) x Front Thickness

And:
Front Opening Height = (Film Height/Projection Distance) x Front Thickness

“These results will give you the minimal size opening that will allow the image to not be vignetted at the edge of the film; you may want to add ~10% to the size to ensure that bits of fuzz or wood or cardboard fibers don’t obstruct the view.

This also assumes that the pinhole aperture is centered onto the middle of the film.

I usually make the front opening with the same shape and aspect ratio as the film, rather than just a round hole. This helps to ensure that the corners aren’t vignetted” said Joe.

Having a background in Graphic arts and the processes involved to create plates (not to be confused w/ Zoneplates) for offset printing presses. I’ve had plenty of experience in the days before Direct-to-plate technology using a “film” output device called an “Imagesetter”. When creating plates for offset presses accuracy is a must and at the time the imagesetter heeded that call. The imagesetter is still used at many local print shops for both Screen printing and Offset printing.

Creating a Zoneplate and Pinhole Apertures

What You’ll Need

Computer with “Vector” based software, such as Adobe Illustrator

This Link to a great Zoneplate Calculator

This Link to a Pinhole Calculator

A shop to with an imagesetter to output your digital file to film

The Zoneplate

At Whiz Kid’s site you can learn all about the in’s and out’s of Zoneplates. Since the subject is “creating” them we’ll stick to that.

1. Determine the focal length of the camera you would like to use your zone plate on.
2. Use Whiz Kid’s Calculator and enter in the information required.
3. Set the output dpi to 9600 in the calculator (this will create an .eps file for you)
4. Download the file
5. Open Illustrator and create an 8.5×11 page. Now open the file you downloaded and bring it into the blank document you just created.
6. If your Zoneplate looks like Figure A, select all and ungroup the selection
7. Deselect the black background and the text at the top and the bottom of the box
8. With only the center images selected, using your align tool, align the image both horizontally and vertically. The zone plate should now look like Figure B.
9. Save your file as an .eps
10. Done

Figure (A)

Figure (B)

The Pinhole

There are quite a few calculators to determine pinhole diameters. Here are a couple links for you to experiment with.

Here is one of them.

1. Determine the focal length of the camera you would like to use your pinhole on.
2. Use one of the suggested calculators and enter in the information required for the calculator.
3. Open Illustrator and create an 8.5×11 page.
4. When you have the results you can to into Illustrator and draw a black box however large you would like.
5. Now, draw a circle the using the results figured by the Pinhole Calculator
6. Center the Pinhole in the black box.
7. Save your file as an .eps
8. Done

Now from the size of the Pinhole or Zoneplate you just created, you can see how much space is left on your 8.5×11 page. Do a variety of Zoneplates with different zones or pinholes experiment with different sizes, shapes or designs till your page is full.

Once you have your files saved you can drop them onto a CD or DVD and take them to a local printer that has “film output” capabilities. A sheet of film at 8.5×11 should not cost more than $15, if it does, shop around.

Ask them for a high resolution Film Positive, Right Reading Emulsion Side Down, output at 100% and the final document size to be 8.5×11.

When you get your Film back it is just like any other film. There is an “emulsion side” and a “carrier side” There are a couple ways to tell which is the emulsion side. The easiest way is to take a razorblade and see if the black will scratch off with very little pressure. If so, that is the emulsion side. The other way is to look at both sides of the film, the “emulsion” side will be dull and the carrier side will be glossy.

When you mount your pinhole or zoneplate to your camera, position the “emulsion side towards your paper or film that your are projecting light to.

Now that you have done this process you should have created an ultra-sharp pinhole and a perfect Zoneplate.