The Graflex “23” 6×9 film back seems rather confusing when you first encounter it, but after a bit of practice it is easy enough to use. However, I recommend sacrificing one roll of film to practice the procedure a few times (rewind the film before you get right to the end, otherwise aligning the film and the backing paper is a bit tricky). If you don’t practice, you could easily end up wasting several frames of film.
It is, of course, essential to have the correct insert with the back, as a 6×6 or 6×7 insert in a 6×9 back will end up taking only eight shots with a lot of space between each frame. Worse still would be a 6×9 insert in a 6×6 back, as all the frames would overlap.
If you are planning to buy a back, you also need to make sure that it is the right one to fit the size of camera you have. They come for 2×3, 3×4 and the more common 4×5 camera backs.
The instructions below are for the 6×9 back without the cocking lever. I assume the 6×6 and 6×7 backs work exactly the same way but since I haven’t seen them, I can’t guarantee that.
I’ll add photos to illustrate this as and when I get round to it, but if you have a Graflex “23” Graphic in your hands, these instructions should be clear enough.
After removing the insert from the film back by squeezing the silver clip and lifting the hinged back:
Make sure the winding knob is just past the number 8 and rotates freely. If not, release the lock by pushing the lever next to the winding handle and wind on until you get past 8.
Insert an empty reel under the winding knob. There is a sprung plate in the base of the insert which you push the reel down into before the other end of it engages under the winding handle
Insert the full film reel in the other slot so that the leader points towards the empty reel.
Pull the film across the roller to its left, across the backing plate (the black side of the backing paper must be showing) over the other roller and insert the leader into the empty roll.
Turn the wind-on knob anti-clockwise until the start arrow on the film is aligned EXACTLY with arrow inside the back. This is a critical step, as there is not much spare film on either side of frames 1 and 8, so going too far or not far enough is likely to lose part of the first or last frame.
Turn the frame counter knob clockwise until it clicks into the “S” position. Again, doing this at the correct stage in the loading procedure – when the arrows are aligned – is critical to winding the correct distance for the first frame.
Place the insert into the back (the winding knob is on top, with the writing on the back the right way up), making sure the dark slide is in position
Turn the winding knob until it locks at the frame number 1 position.
You are now ready to insert the back into the camera, remove the dark slide, and shoot.
After taking the first frame, move the silver lever to the left to release the lock on the winding handle and allow you to wind on until it locks on frame 2. And repeat.