I got into LF and built a darkroom at the same time. Probably should have given up my day job, too. Bought a venerable but very solid Beseler 45MXT enlarger w ith an Aristo cold light head. The enlarger has a very small filter holder belo w the lens that won't fit anything but the old Polycontrast filters, and is so s mall it vignettes the image if I'm using a 150mm lens and am not really careful. I just lay the filters on top of the holder. Anybody know of any better way t o use the filters? I would prefer not to put the filter below the lens. If I have to leave it there, is there a way to support the filter without going to a machine shop?