Ok... Got my plex-knife. Don't have my fresnels yet, as the Pro kit is backordered. But... When I do cut them, do I need to make sure the center of the "grooves" are centered with each other? I am doing an un-split configuration, and I have heard that fresnels not aligned right will make rainbow artifacts, etc. This may only be if the fresnels are too close (<10mm). So, do I have to cut them exactly alike, with the centers aligned perfectly?

Yoder

Just curious but why do you need to cut them? If it is because they are bigger than your lcd just make the fresnel frames cover what you don't need rather than cutting them.

Well, that would make my box bigger, i hear of people cutting them, I mean I guess I dont have to, but it would make my box smaller.

Yoder,
I just cut a pair last week.
Use a clean, flat surface, like an old drawing board. Mark up the to ends where you want to cut, making shure you cut off exactly the same amount on both ends. Put a soft wrapping paper under the fresnel and place the fresnel on it with groves down. Clamp a straight edge on the fresnel at the cutting line. Score it 15-20 times with the plex knife and then gently lift the opposite end with both hands and it will snap off. All 4 cuts turned out to be perfect for me.
Good luck with the project.
nvl

Cool, thanks man. What about centering them up?

Just make sure you cut the same amount on both sides. For example if you wanted to cut 1 inch total from the width then cut a 1/2 inch from each side on both fresnals. By cutting the same amount off of both sides that will keep them centered.