Very good. My only issue is that I cannot use my takahashi 2 inch diagonal with the field flattener for doing my alignment routine or visual observing. OPT is researching this problem for me and I am eagerly waiting the reply to my questions regarding this problem.
This flattener made a WORLD of difference from the stock telescope. The images I'm getting with an STL-11000M are astounding with this!
This is an amazing piece of glass, which transforms both the visual and imaging experience when using the TOA-130 NFB. The field curvature of the TOA *must* be corrected for a satisfying imaging or viewing experience, and other flatteners just do not work nearly as well -- believe me, I have tried. The 67-FL is very forgiving of backfocus distances when used with smaller imaging sensors (up to about 24 millimeters diagonal, and with larger sensors is absolutely required. It is a must-have for imaging of any sort at the native focal length, and is really a should-have for visual use as well, flattening the visual field in a way that thoroughly delights the eye. Even though it adds nearly $1000 to the cost of an already-expensive refractor, your TOA-130 just will *not* live up to its potential without a matched flattening element in the optical train. Takahashi should not allow the TOAs to be sold without this device. Do NOT purchase a TOA refractor without one of these!