What Nikon or Canon lens, what MM sizes are recommended, what are you folks using? What's the widest lens and the tightest lens you folks are using with your letus units? What's too much? How wide can you get?

you can check out these lenses :

Wide-angle lenses
24mm f/2.0 nikkor
35 mm f/1.4 Nikkor
28 mm f/2 Nikkor
28 mm f/2.8 Nikkor (AIS, close focus to 0.2 m)

Normal lenses
50 mm f/2 Nikkor
50 mm f/1.8 Nikkor
50 mm f/1.4 Nikkor
50mm f/1.2 nikkor

Medium short ("portrait") lenses
85 mm f/1.4 Nikkor
105 mm f/2 DC Nikkor
105 mm f/2.5 Nikkor (Gauss design)
85 mm f/1.4 Nikkor (MF, AIS)

Short telephoto lenses
200 mm f/2 ED-IF Nikkor (AIS)
180 mm f/2.8 ED Nikkor (AIS)

zoom lenses
80-200mm ed af