Here are the steps on how to mount the Diana 35mm back into the Diana camera:
You will need:
The adapter of your choice.
33×48mm (extended panoramic shot with exposed perforations), 27 images per roll
24×48mm (extended panoramic shot without exposed perforations), 27 images per roll
33×34mm (square image with exposed perforations), 36 images per roll
24×36mm (standard rectangular image without exposed perforations), 36 images per roll
Your Diana F+ 35mm back is interchangeable with the usual Diana F+ back.
In order to change into the 35mm back, you’ll need to make some preparations. Unlock and remove the Diana F+ back.
Remove the medium format take-up spool. And carefully remove the “Medium Format Film Plate.” This is the thin strip of plastic at the bottom of the camera with two “arms” on either side of it. Grab the Film Plate by the middle and carefully pull it out. Don’t grab it by the “arms,” as they can easily break with too much force.
IMPORTANT: Store the take-up spool and Medium Format Film Plate in a safe place. You’ll need them for the next time that you want to shoot medium format film through your Diana F+.
Now, let’s mount the 35mm back. Line up the square Shutter Rear
with the Diana’s square shutter rear.
Push the 35mm back straight in. Now, push it up so that the top seam fits perfectly with the Diana F+
Finally, move the Lock Switch to the “Lock” position.