Directions for making your own accurately sized apertures
Items that you’ll need:
- an appropriately sized quilting needle
- a pin vice
- a micrometer
- a cardboard drink coaster from a local eating establishment
- a magnifying device (for us older folks)
- a suitable pinhole material, the thinner the better
- extra fine sandpaper, I like to use 1000 or 1500 grit
Gather all of your materials and use a clean, well lit area on which to work. Having everything at hand will make the job go smoother and be less frustrating.
Pinholes provide better image (more “sharp”, as it were) the more accurately “round” they are. Oval or out of round pinholes give blurry pictures, laser cut pinholes give sharper images due to their accurate shape. Matching an appropriately sized pinhole to a particular camera’s focal distance will yield the best, “sharpest” image. This is a convenient way to make your own pinholes that are fairly accurate in size and shape.
Lay out your pinhole material; the thinner the material, the better. A good hobby store should carry brass or stainless steel shim stock or you can use the aluminum from a beverage can. I have had consistently good results from .002 inch copper sheets that I bought years ago at an art supply store. Copper is soft, accepts the drilling process and sands well too. You’ll need to find an appropriately size for your pinhole; I have used several pinhole calculators available online. For this demonstration, I’ll make a pinhole that measures .0225″. That would be an appropriate size pinhole for a camera with a focal length of 190mm. Please note: I apologize for the mixing of metric and standard measurement, my micrometer measures in inches while I still measure most camera construction in metric. There are metric micrometers available for purchase.
You’ll need to dial the desired number into your micrometer. There are several ways to learn to set up a micrometer. I learned how to use mine from the instructions that came with the tool, an online tutorial and from experience in working with it. I paid approximately $25 for my micrometer at a local hardware store. Simply put, each complete rotation of the barrel of the micrometer measures ¼ of 1/10 of an inch. The .0225 inches shown on the dial represents the same measurement that should be the diameter of my finished pinhole.
Take a quilting needle that won’t fit through the measuring rods when set to your pinhole size. A number 8 needle will do in this case; a number 8 needle should have a shaft size of .0240 inches. Place it gently-point first-into the measuring rods on the micrometer until it stops, don’t force it. When it does stop in the measuring rods, the diameter of the needle is .0225 inches, get it? Good!
Bring the pin vice collets up over the other end of the needle and gently tighten the pin vice. By pushing the pin vice all the way up to the measuring rods on the micrometer and then securing the needle, you’ll end up with a needle sized to make a pinhole that is fairly close to .0225 inches in diameter.
Now, to drill your own pinholes; patience is the key. The pin doesn’t “drill” through the material as much as it is pushed through and the rough, protruding edge on either side is smoothed off. Place the metal stock on the drink coaster and press down onto the material with the pin vice and needle while rotating the pin vice with your fingers. Push and spin the vice slightly until you have dimpled the material. Now, lightly sand the opposite side with the sandpaper.
Repeat the process with the pin vice; spinning and pushing, flipping and sanding, until the pinhole enlarges slightly with each turn. Flip, sand and drill again until the pin vice collets are almost touching the metal sheet. Sand across the pinhole in different directions, slowly and with light pressure so as not to elongate your pinhole.
After repeating the process several times, the pinhole will be finished. Once again, patience is the key and you’ll have to use your own judgment as to when the material is sufficiently sanded and there is no more material that needs to be removed. This is a side-by-side comparison of a hand drilled pinhole that I made and laser drilled pinhole taken with a lensed, digital camera. The two images are fairly identical, the price of the pinhole being the only great difference. The laser pinhole is fairly costly and the hand drilled pinhole cost next to nothing to make, mostly your time and effort.
Good luck and good pinholing.