I've seen some references early in the thread to "4x4 masks"; what does that mean? Is that a 4cm by 4cm mask? I have a couple of Holga's and don't recall seeing any ot those. I have 6x6 and 6x4.5 masks. I kind of like the light falloff with the 6x6 mask. Without that, they might not be Holga images! But thanks for the suggestion of taking the mask out; that may offer some new possibilities.