Mike,

I would describe a tip-tilt mirror as "first order" adaptive optics as it
rapidly responds to real displacements of the image via optical methods.
Obviously, adaptive optics can become quite sophisticated but I would not
say that it requires that glass be bent.

This is kind of like arguing whether or not Pluto is a planet.....

Del Johnson



"Mike Simmons" wrote in message
...
Hi Don,

I'd just like to double-check something. It seems that you would then
agree that the SBIG AO-7 "adaptive optics" unit -- a tip-tilt mirror --
is truly "adaptive" optics. Is that right? I've asked this of others
working in the field -- astronomers and optical engineers -- and get
varied responses. Some say tip-tilt is "adaptive", others (a minority,
I think) say it's not. Most, however, give me a quizzical look and say
something like "Well, you could say..." (fill in the blank). So I'm
very interested in the view of someone not just building a particular
unit or using AO but having spent many years in the business.

Best regards,

Mike Simmons