Repairing the Big Shot Range Finder

The Polaroid Big Shot has a simple mirror arrangement to facilitate focusing. Four small rectangular mirrors are fixed in a frame, with slanted mirrors at top and bottom, and two mirrors laying flat in between them.

When I received my Polaroid Big Shot, one of the mirrors in the rangefinder was no longer attached. The Big Shot Manual (download it here) says that focus is achieved when the lens is 39″ (100cm) away from the subject. So I’m going to start with that information. Here’s my crude setup:

I removed the range finder from the camera housing (4 screws total — open the film back and see the first 2 screws, then the range finder cover is hinged. There are 2 more screws inside holding the bracket).

photo of calibration setup

Then I taped the mirror bracket to a light stand, and moved it 39″ (the focus distance to the lens) + 9.5″ (the distance from the lens to the rear of the range finder bracket) away from a white board.

On the white board, I drew a simple pattern that would give me something to line-up on. The range finder works by moving yourself and the camera forward or backwards, until the image (showing in the white square) moves and aligns with the image on the whiteboard. In this photo, you can see that my image is below, and to the right of the design drawn on the whiteboard. Since I’m the (presumed) proper distance from the whiteboard image, I need to adjust the mirror until the two images line up.

The Polaroid Big Shot

I have in mind to create some portraits in the manner of Andy Warhol. And so I set out to get the camera-of-choice for most all of his portraits — the Polaroid Big Shot. Designed strictly as an indoor portrait camera, the bulky Big Shot was in production from 1971-1973.

Here are photos of my Polaroid Big Shot:

Over at there’s a great read on the Big Shot by Cheyenne Morrison. I think it’s particularly interesting to read the letter from one of the inventors (Bruce K. Johnson), describing the design philosophy for the camera

The main advantages of the long focal length and the flash arrangement in the Big Shot are:

1. Standing back produces less “distortion” of facial features than occurs when getting close. If you get too close to a subject, the nose looks too big compared to the ears. This is a simple matter of perspective or geometry. The Big Shot forces the camera to be at a substantial distance when compared to other Polaroid cameras for the same sized head image.
2. Standing close to a person to take a picture makes them uncomfortable. You are invading their space. The Big Shot was less intrusive than our other cameras.
3. The brightness/darkness ration of a picture due to flash is minimized when taking a picture from a distance rather than up close. This is known as the inverse square law of flash illumination. There is less brightness difference between the ears (further from the camera) and the nose (closer to the camera) or the background (even further from the camera.) when using a long focal length lens which allows the subject to be further away for the same head size.
4. The flash used in conjunction with the Fresnel lens allowed a small aperture, which gives good depth of field, because it concentrated the light onto the subject.
5. The flash is far enough away from the optical axis such that “Red Eye” was not commonly observed in the pictures.
6. The flash is vertically mounted over the lens, minimizing any visible shadows on the background.
7. The combination of very bright flash , small aperture, and relative short exposure time minimizes the effect of ambient light, which helps to get consistent exposure results. Using the Big Shot outdoors in bright sunlight would produce some overexposure, and is not recommended for optimum results. Normal indoor lighting has little effect on the exposure.

Bruce K. Johnson

For more info, here are PDFs of the Owner’s Manual and Polaroid’s Patent:

User Manual for Polaroid Big Shot (PDF, 8.4mb)
U.S. Patent for Polaroid Big Shot (PDF, 9.3mb)

I got the camera from the online auction site (they range from $20 to $200), but my shutter was not working, and the rangefinder has a mirror that’s come loose. So I set out to disassemble it.

The Breakdown (or, taking a wrong turn to Disassembly)

So, I decide to disassemble the Big Shot, and see if the shutter release can be fixed. I found a little bit of information on ( but it makes it sound like you have to break things to get it apart (spoiler alert).

I tried to gently, gently I say, pop out the acrylic Fresnel diffuser. I broke one side of the diffuser holder uprights, then broke off the other one, then broke off a chunk of plastic from below the lens, then cracked the diffuser. Then, voila, it was almost disassembled! With the acrylic diffuser removed, the paper label comes off, and you can see the two screw holes holding on the front nosecone. This nosecone holds the lens/aperture, and the aforementioned diffuser. It also interfaces with the flash cube mount.

Maybe a Better Way

Knowing where the two Philips screws are located would’ve made it a lot easier to disassemble. With the screws out, the nosecone assembly (lens, aperture, acrylic Fresnel diffuser) comes off easily, revealing the shutter mechanism and the mechanism that fires and rotates the flash cube. The screws are set deep into the nosecone, and I tried a couple of different jeweler’s screwdrivers to find one that had a shaft that was skinny and long enough to reach. The screw holes are about 1 1/4″ (33mm) deep.

I’ve modeled a drill template to help locate the holes, and make it easier to drill through the acrylic diffuser and paper label. 3D Printer files have been uploaded to Thingiverse.

I used a Dremel tool on the Dremel drill press stand, though you could probably easily do this with a handheld drill. I used moderate speed, and it never felt like the acrylic was going to crack. I used a small drill bit (around 1/16″ or 1- or 2-mm), then I finished with 1/8″ (3- or 4-mm).

You’re drilling through the clear acrylic Fresnel diffuser plate, and a printed paper label underneath. The holes really only need to be as big as your screwdriver, because you can just remove the drill jig/template, then unscrew the screws. Because I had glued the nosecone back together before drilling the holes, and forgot to install the screws first, I had to make a bigger hole in the template to allow the screw heads to fit back in.

The Big Shot Disassembled

Here’s a collection of photos of the internal components.