Brandon Orthoscopic 12mm

2.0 Brandon Orthoscopic 12mm

Looks good; Easy to come into focus.

Expensive; Practially no eye relief; Narrow FOV

At a recent star party I had a chance to use a Brandon 12mm eyepiece in my 8" f/10 SCT. The first thing I noticed was the lack of sufficient eye relief. At best I'd say that is was 3mm to 4mm and possibly a bit less.

This is a four element eyepiece with a 40 to 45 degree FOV. It is expensive at almost $200 new, if you can find them. On the plus side, fit and finish was excellent. It came into focus quickly and easily. The center 50% of the field was tack sharp. From 50% to about 75% out, it was not too bad but I starting to see some sea gulling of the stars. Beyond 75% from the center, it was not worth much. It is hard to like an eyepiece when your best view is 50% of 45 degrees. I found this EP to be contrasty, with some light scattering at the field edge. To me, in my f/10 which is very forgiving to most eyepieces, this EP was only average at best. The lack of eye relief was the biggest problem for me.