Quote:

---

I agree with Ron that other so called "field flatteners" (Fujinon FMT-SX, Nikon SE, Pentax PIF) appear to correct astigmatism, but not field curvature.

---

Seems to agree with what I've found. Examples:
Fujinon FMT-SX 10x50, all or nearly all of the outer field aberration is field curvature.
Nikon SE 10x42, approx 80% of all outer field aberration is due to field curvature.
Nikon SE 12x50, approx 75% of all outer field aberration is due to field curvature.

Note, these binoculars outer filed total aberration is very well controlled, it's just being pointed out here how much of what is there is due to curvature.

Nikon Prostar 7x50, close to zero.

edz

--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21

Post Extras