If this has been discussed previously forgive me and maybe someone could direct me to the thread.
It seems that APM is currently selling three 100mm binos; the Standard (achromat, formerly 'semi-apo'?), the ED and the SD.
I appreciate the shortcomings of an achromat for the bright, solar system objects. But for star fields, clusters and deep sky, can the ED performance justify the additional $1,050? I'd prefer to spend that money on the mount.
Are these the same binoculars with exception of the objectives? Field illumination and curvature, brightness, performance with a given eyepiece?