Ah yes, I should have inferred the difference. For now, with the rarity of me loading 35mm film into the 120 pinhole camera, I think I'll be fine with guesstimating the number of "non sprocket hole clicks" and subtracting a few every time. I got 5 shots off of a roll of 24-exposure 135 film, which is pretty much how many I should have gotten, mathematically. I don't think I could've squeezed out another, even with very careful counting and spacing...