PHOTOGRAPHY: Creating Perfect Pinholes and Zoneplates

Zoneplate's and Pinholes are alternative light focusing elements vs. a conventional lens.

When I first began shooting Zoneplate images, I instantly became interested in creating my own Zoneplates with a number of zones and to accommodate a variety of focal lengths. The traditional process of creating Zoneplates, is more work that it needs to be especially if you are concerned w/ the accuracy of your final Zoneplate. Accuracy is also a concern for Pinhole photographers when creating their self-made apertures. You can also use this same process to create pinholes.

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 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.

If you don't know what an imagesetter is check out http://en.wikipedia.org/wiki/Imagesetter.

I'll upload the instructional photos asap, in the meantime, I have all these steps w/ photos here.

Step 1 What you will need!

Creating a Zoneplate and Pinhole Apertures

What You'll Need

Computer with Vector based Illustration software, such as Adobe Illustrator

This Link: Create Zoneplate Design Tool

This Link: Pinhole Size Calculator

Comments

[Myself]

Some context would be helpful. What is a Zoneplate, why is it capitalized (is it a proper noun?), why would I want to use one, and what are the advantages of making my own over using a store-bought one?

[geo]

A zone plate is a lens which uses diffraction, rather than refraction, to bend light. Diffraction is the tendency for waves to bend around tight corners, or circular edges in this case. One of the advantages of a zone plate over a lens, is that you don't need a refractive medium (e.g. glass) to bend the light. You just need some opaque stuff and some transparent stuff. Indeed, the transparent stuff can be open space; it doesn't need to be film as in this case. Since you don't need a refractive medium (or even any transparent medium, for that matter), the zone plate is used to focus wavelengths of light which don't easily go through normal glass. Another advantage of the zone plate is that it can be _entirely_ flat. It doesn't need fancy curved surfaces like a lens does. So you can produce it with a lithographic (or in this case, photographic) process, instead of grinding or molding. For this reason, it is used for making incredibly tiny lenses for focusing x-rays, and probably other things. Another way to think about and understand the zone plate is that it is the hologram of an infinitely tiny point source. You already own a device with a zone plate: It is used to focus the light from the laser onto the reflective surface inside a CD or a DVD disc. Also interesting, is the zone plate need not be for light! Any wave which can be diffracted, can be focused using a zone plate. For instance, you can make an acoustic zone plate (to focus sound) out of any acoustic insulator material (plywood, acoustic foam, foam core board, etc). Something to keep in mind when using a zone plate, and RCline didn't discuss this above, is that the focal length of a zone plate is _strongly_ dependent on the wavelength. In particular, the focal length is inversely proportional to wavelength. So, if you want a sharp image from a zone-plate based camera, you should probably pre-filter the light using a colored filter.

[CeeJay.dk]

Since a zoneplate is highly dependent on the wavelength and we are trying to create a zoneplate with a photographic process can't we make a zoneplate that accounts for different wavelengths, by making several virtual zoneplates for several wavelengths and combine them to make a single zoneplate that would give a sharp image for more than one wavelength ? It's hard to explain , but I hope you understand what I mean. To put it simpler - Don't create a black and white zoneplate - create a multicoloured one. I imagine that the edges of the zoneplate would look like a rainbow if you did this.

[RCline]

Thank you "Geo". Another reason you may want to produce a zoneplate yourself is thisthis.

Another nice thing about film pinholes & zoneplates are that if you are shooting digital, you don't have to worry about dust making it's way to your sensor.

[Ribs]

Why would you want to use a zone plate? and what does it have to do with a pinhole camera?

[RCline]

A zoneplate is an alternative to using a pinhole. The image I posted from Italy, was taken w/ a zoneplate. A couple things the zoneplate will do for you: A) Cut your exposure time significantly (usually takes about 1/4 the amount of light for an exposure) B) Softens the image and gives kind of a cool fuzzy look. I'm sure there are more reasons than these people use them, but these are why I like them. If I want something a little sharper, I'll shoot w/ a pinhole. Thank you!