I have an Arca Swiss Field 4x5. I want to start making square exposures (4x4") using a large format view camera. I made a mask out of matte board with a 4x4" opening, and taped the matte board to the inside of my film plate (so it is taped right in front of where the negative holder slides in). I am having some issues with this.
I made a test exposure, and the negative came out measuring 4 5/16th" wide. Why is this happening when the opening of the mask is 4"?
And when I look through the ground glass, the borders of the mask are basically non existent, I can barely even see them on the sides of the ground glass, they definitely are not half an inch wide on each side when being viewed through the glass.
Has anyone done this before? How would you recommend I go about doing this?
Any advice would be greatly appreciated!!