By hand, it may be difficult to have a good sense of observation, made there may be a lot of aberration.
Focal length of 120mm, caliber 40mm convex lens
Focal length of 40mm, diameter of 25mm convex lens
Aperture of 20mm concave lens
Lens with a focal length of 120mm, a caliber of 40mm lens
Aperture of 20mm concave lens eyepiece
Focal length of 40mm diameter of 25mm convex lens on the final zoom lens
Number of films optional mirror diameter can choose, but it is best to support, have to find a professional website to solve the "color" and "aberration" problem.