Silverbased

In an earlier post, I showed how to modify a Polaroid OneStep camera so that you could take multiple exposures onto 600 film. Lately OneStep cameras have become so cheap and ubiquitous at thrift stores and on eBay that this is a creative way to reuse a few.

Yet there are a couple of problems with the OneSteps. First, most models were very basic, plasticky, fixed-focus cameras, not offering much versatility. The second problem is that their frame-counting mechanism locks the shutter after 10 shots. If you’re shooting multiple exposures onto each frame, at some point you’ll need to remove the film pack in a dark room to re-set the counter, which is inconvenient.

Polaroid’s SX-70 models were much more sophisticated than the OneSteps. They featured a compact, collapsible body, a good-quality glass lens, and true SLR focusing all the way down to 10″. However they’re a bit tricky to disassemble, so the “kill switch” mod I described earlier would be rather complicated to try on an SX-70.

An SX-70—even a thrashed one like my white model 2—is a sleeker, nicer camera than any of Polaroid’s OneStep models.

But Flickr user amalia chimera called my attention to a YouTube video by her friend Brian (whose demonstration of double-exposures on a Spectra camera I had previously linked to). In a second video he shows a technique for fooling SX-70 cameras to make double-exposures possible.

Basically, the trick is this: An SX-70 has an interlock so that if the film door is open, the shutter and eject motor won’t operate. However by pressing the door-sensor lever with a narrow tool, you can take a shot even with the door open. Because the feed rollers are disengaged then, the print does not get ejected and developed. You can nudge the print back into the pack and make a second exposure.

An SX-70 does require an exposure adjustment to use 600 film. But that’s a minor problem. And I would much rather shoot with an SX-70 than a cheesy OneStep, so Brian’s technique really excited me. Plus, no permanent surgery to the camera was needed. So here’s a few refinements and additions to what Brian’s video shows.

Start by cutting a bit of kitchen match or barbecue skewer so that it’s exactly 41mm long. (I’ll explain the reason for the piece of tape later.)

When you open the camera’s film door, you will see a small, dull gray piece of folded metal on the left edge—directly below the plastic ribbon cable. There is a peg on the film door which rises up behind this when the camera is closed; it lifts a small black plastic lever. This is the switch we need to “fool” with our special tool.

By using a stick exactly 41mm long, we can brace it against the film door’s light baffle and keep the switch pressed upwards.

With the switch overridden, you can take your first exposure without ejecting the print. Because you might walk around in full daylight for some time before finding the right subject, there’s a risk of light leaking into the front edge of the film pack. If you’d prefer to avoid this, you can wrap the front of the camera with a shroud of black cloth, paper, etc.

Cloth shroud held in place with rubber band

One of the many clever features of the SX-70 is that any adjustment made to the lighter-darker dial would be reset to zero whenever the camera was folded. However you will probably find your double exposures will look too washed out if you don’t set the dial towards the darker end of the scale before shooting. It’s a slight annoyance that you have to remember to do this every time you open the camera.

Remember to turn the exposure dial towards the black!

When you take your first image, about 1/8″ of the print edge is shoved out of the film pack. Ordinarily this would feed it into the rollers, which spread the chemical goo inside the print and start development. But we’ve prevented this.

It’s extremely important that you shove the print edge as far back into the film pack as possible, behind its flexible plastic light shield, until no more white is visible. Otherwise you run the risk of the camera ejecting two prints at once, spoiling both. But the wood stick we cut turns out to be a handy tool for nudging the print back into place.

Try to go somewhere in dim light before shoving the print edge back into the pack, since this is the stage where you’re most likely to flash the bottom of the image with light leaks. But I’ve become kind of fond of the “row of teeth” light effect you sometimes get from this (seen in the sample image below).

Now close the film door and shoot the second image. As I noted last time, any bright area in your subject tends to blow out whatever detail might have appeared in the other image. Experiment with leaving lots of dark, blank areas in the frame to give the clearest “double-iness” to the final photo. The SX-70’s extra-close focusing can help you isolate simple and uncluttered subjects.

A happy discovery was that an SX-70 does not lock the shutter after 10 exposures (at least, my Model 2 doesn’t). The frame counter goes down to 0 shots and stays there; but you can keep on clicking until all the prints in the pack are used up. But it’s up to you to keep track of the correct count, of course.

Remember that piece of tape wrapped around the stick? Here’s one more tip: You can always keep your double-exposure tool handy by taping it under the SX-70 viewfinder hood. There’s enough space at the back end to allow the viewfinder to fold normally; and the stick won’t get lost this way.

.