Horseman 6x7 back for 5x4: Operatiing question

[pdeeh]

I just acquired a Horseman 6x7 rollfilm back with a lever wind-on for 5x4 rather cheaply. It's a bit scruffy but seems functional, and I intend to use it on my 5x4 pinhole camera.

The only thing I can't work out, and can't seem to find online, is a satisfactory explanation of what the small lever with left-pointing arrow (see attached pic) actually does. I'm presuming it forms part of the winding mechanism, but as the main thumb-lever seems to transport the film OK, I don't understand how the wee one fits into the process.

 

[polyglot]

It's probably the thing you push to tell the back that you've made an exposure, which will allow the crank to advance to the next frame.

 

[ic-racer]

It's the thing you push to tell the back that you've made an exposure, which will allow the crank to advance to the next frame.

That looks like a used unit, so, in addition to the above information, you will also want to make sure the arrow on the film back is in the circular window before closing the back and advancing to the first frame. Also, check that the springs that hold tension on the take-up spool flanges provide some resistance to turning.

 

[pdeeh]

Thanks to both.
Yes I worked out what the window was for , and while it's clearly very well-used, everything works smoothly and the springs are indeed suitably springy. The only thing that I can see that obviously needs attention are the light traps,

I'm making some exposures now, so I'll see if it's all in order once I develop the flim.

 

[pdeeh]

Negatives look fine. No obvious light leaks, frame spacing looks OK.

As it cost less than £20, I'm rather pleased (a 6x9 would have been better still of course )

 

[EdSawyer]

Yeah, the 6x7 and 6x9 ones are cheap and common. Sadly the 6x12 ones are not.