And now for something completely different. . .
The Spectra System was probably Polaroid's last great idea. It uses a slightly larger format than the SX70/600 series cameras, and it produces a rectangular image rather than square.
My Spectra II is a $6 thrift store find with sonar autofocus, autoexposure, built-in flash, and a self timer. It folds up nicely, and I've fitted it with an Impossible frog tongue. It has become my “go to” instant camera for integral film.
I have a bit of a love/hate relationship with The Impossible Project. I love that they are making film to keep these old Polaroids alive; I haven't had good luck with a lot of it, at least the color versions. To be fair they have been working to perfect their products, and they do keep getting better. I loaded my workhorse with their fabulous PZ600 Silver Shade black & white film and took it to Deerfield Fair one evening.
Good morning from the Chair Car Division
The Spectra can be used to easily make double exposures via a bit of trickery with the self timer. After using the self timer, the camera will not eject until the switch is turned off. If you close the camera before resetting the timer the electronics “forget” and the camera will behave normally when reopened. Take your second shot and Voila! double exposure.
If you want one, your best bet is a local thrift store. They tend to be loaded with these cameras, and they still work. Barring that, there's always eBay.