Quick Photography Tips

In this tutorial I’ll show you how I modified an Instax 100 instant (polaroid-esque) camera to be able to take double exposures like the one below. It isn’t really a photography tip and it’s not particularly quick so not the usual stuff but here goes…

Warning: Before you try this at home note that it’ll probably void any warranty, you may break your camera and that there’s a big capacitor inside this camera that might give you a nasty electric shock if you start fiddling around inside. Proceed at your own risk. If you do, be sure to read the whole tutorial thoroughly before you start as there are useful pointers throughout.

What we need:

• An Instax 100 camera- There is an Instax 200 that is practically the same but the 100 will work better for this hack as it has an exposure switch rather than an exposure button. As we’re doing double exposures we want to underexpose each one. I don’t think the button on the 200 will let us do this (I haven’t tried).
• A switch - I’ve used this SPDT switch but an SPST will work too.
• Some wire
• A soldering iron & solder
• Miscellaneous tools - watchmakers screwdriver (to fit Instax screws), drill, wire cutters, etc

In normal operation, when you press the shutter button the Instax opens and closes the shutter and then runs it’s motor for a few second which pushes the film pack up and through the rollers spreading the developing chemicals over the image. To make the Instax give us double exposures we need to decouple the eject process from the shutter opening. To do this we will add a switch that allows us to turn off the eject motor but still fire the shutter.

There are 6 little screws to remove to open up the Instax - 2 at the top on the strap lugs, 2 just above the battery compartment and 2 on the base. Once they’re out it should open up. Don’t pull too hard as the back will still be connected by a ribbon wire shown in the picture to the right.

There are three major parts to the Instax 100 - the front shell, the back panel (with the controls) and the middle bit which contains everything else! For this hack we only need to remove the back panel but the front shell will also come loose when you remove the screws as above. The back panel can be detached completely by undoing the ribbon wire connector where it meets the middle section circuit board. The connector is a clip that can be undone - don’t just pull it out!

We then want to install the switch in the back panel. I placed it on the side just above the battery compartment. There’s not a lot of spare room inside the Instax but there is a bit just below the motor that my switch fitted into. You want your switch to be near the motor so that you don’t have to do too much rewiring inside. If your switch won’t fit inside you could just feed out some wires and mount it on the outside. Here are the photos of my switch in position.

Here’s a photo of the Instax opened up with the switch mounted. When the back is folded back over (be careful of the ribbon wire when doing this) the blue switch body slots in nicely in the little gap below the motor…

That’s the mounting sorted. Now for the wiring. Fortunately we don’t have to do anything particulary complicated to make this work. All we have to do is wire up the switch so that the motor is either connected as normal or is bypassed depending on the position of the switch. Our switch then effectively becomes an eject on/off switch.

To achieve this with an SPST switch, the two switch terminal would just be connected across the two motor terminals so that when the switch is on, the motor is shorted out of the circuit (ie switch on = motor off confusingly).

I used an SPDT switch that either connects the motor into the circuit or bypasses it through the switch. Remove the switch from its mounting before you do the soldering else this stage will be very fiddly. Make sure you leave enough wire you put it back in again though!

Here’s what that looks like all soldered up and with the switch bolted back into its mounting…

Now we just put it all back together - reconnect the back panel ribbon wire to its connector and put it back together. Check the power button still works (it seemed to only work when the back panel is replaced so everything is light tight but I didn’t work out why) and check the motor still runs with the switch in the appropriate position (the camera may not turn on if it can’t run the motor as the motor also powers the lens (but not the shutter)).

The process for taking a double exposure is as follows. You can try this without film to check it all works.

1. With the motor on, turn on the camera. The lens should whizz out to its ready position.
2. Set the exposure switch to Darken.
3. Open and close the film bay. The camera should then think you’ve loaded a new film so there is a black sheet covering the film that it needs to eject.
4. Press the shutter button. The shutter should not fire but the motor should run for a few seconds (this is to eject the black sheet). The counter should go to 10.
5. Press the shutter button again. This test normal operation - the shutter should open and close and then the motor runs for a few seconds.
6. Turn off the motor using your new switch then press the shutter button again. This time the shutter should open and close but the motor will not run. The Instax gets a bit confused at this point but eventually will flash the LED below the viewfinder to show it’s given up trying to run the motor. The arrows that point to the focal distances on the LCD will both light up (that ain’t right - we know we’ve confused it now!).
7. Assuming you only want a double exposure, turn the motor back on. Only after the red LED has flashed can you turn the motor back on. If you do it too early the Instax may still be trying to run the motor and your image may get ejected.
8. The Instax is a bit confused at this point but it’s ready to have another go. Press the shutter button again. The shutter opens and closes and then the motor springs into life and ejects your double exposed photo which you can then watch develop into two images all at once in front of you!

One problem with this hack is that the film counter will count two exposures but you’ve only used one film sheet. When the counter hits zero, you can reset the counter by opening and closing the back or (I think) by removing and replacing one of the batteries.

Remember that the camera will then think that there is another black slide to remove but you may be able to get around this by turning off the motor for the first press of the shutter button (I haven’t tried this bit yet).