Re: [tmboptical] Re: star test with TMB 105mm f6.2 refractor
----- Original Message -----
From: "ketelbinkus" <laserdermatologique@...>
Sent: Wednesday, July 31, 2002 7:35 PM
Subject: [tmboptical] Re: star test with TMB 105mm f6.2 refractor
> However, with optics, performance tmo could be quantified in a nearly
> scientific and objective way. It is a pitty that manufacturers do not
> give real comparable information on their optics.
If you read a camera magazine you will see that camera lenses are always
qualified according to a number of objective standards. This could be done
too by the reviewer if he has the proper equipment and training. With many
manufacturers, one might get a prize or a real lemon, from purchase to
purchase, their standards of QA are so loose. Even some upper "name brand"
may yield a super-fine model which finds it way into the reviewers hands,
but this does not mean you will get the same. However the better
manufacturers do give real comparable information, such as A-P and TMB.
This could include anything from a strehl ratio at a given wavelength, to an
MTF curve, RMS figures and so on. Even if these are not provided for an
individual instrument, they are given for a line of product with a lower
When dealing with a person like Tom who says he personally guarantees his
scope will do .95 strehl or better, that is good enough for me. I have no
doubt mine is even better than that, and, as I have told Tom personally, I
have given my scope a very close look from time to time, and the closer I
look, the BETTER it looks! I will not throw up numbers, but having studied
the diffraction pattern very closely and knowing Suiters book inside out, I
can only say that the TMB optic is right at the brink of theoretical
PERFECTION, second to none. If anyone says otherwise, they are blowing hot
And I believe you will get that EVERY TIME you buy a TMB.