I have had my Diana Instant Back+ for about a year now, and I have to say it is a really neat accessory. I actually have used my Diana F+ more with the Instant Back than with actual 120 film. The first time that I used it was in Ireland while trekking around the country in our rental car. I was able to get some fantastic shots with the pleasure of having them instantly in your hand. My only problem was that I forgot to buy batteries before the trip and we had to scramble across tiny towns looking for an obscure type of battery.
Anyways I just wanted to post a quick tutorial on the use of the back with your Diana F+ camera. In my experience I received the box with the Instant Back and right away wanted to use it, though there weren’t clear instructions to me on what needed to be done. I’m not sure if I lost the manual or what, I can’t really remember, but your first step if to open up you camera and remove the back as if you were going to put in some film. Inside you will see the 120 spool where you film winds on to, as well as a small bracket at the bottom of the camera that holds the spool and the film in place. You may also have a square frame inside depending on how you were having your film turn out in terms of sizing. You need to take all of these components out of the camera as they are not really needed to take the photos and my cause issues in your shots. Keep all of these items in a safe place, as you will have to put them back if you want to use film again.