A wider lens will give you a shorter working distance. The Schneider 40mm is a nice lens, but it isn't wide enough to (for instance) make a big print from a half frame negative on most enlargers. Schneider also makes a 28mm enlarging lens, but most enlargers will not focus using it - it's just too short. Some enlargers have recessed mounting boards that will work with this and similar lenses. 35mm enlarging lenses exist, and they are a useful solution, if you can find a really good one. Some wide lenses have limited coverage and may not cover a full 35mm frame. You could also possibly adapt a wide angle camera lens to your enlarger, but camera lenses are generally less sharp than enlarging lenses, and you will see a deterioration in the image. Another possibility is to attach a close-up lens to your enlarger lens. This will shorten the focal length, but you will lose sharpness. The more traditional way to handle this problem is to either tilt the enlarger head horizontal or reverse the enlarger mechanism on the baseboard so that you can project the image on the wall or floor.