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Is the Tak TSA really a Super-Apo?

Started by lineman_16735, 10/26/2008 07:44PM
Posted 10/26/2008 07:44PM | Edited 10/26/2008 08:40PM Opening Post
I have one and am pleased with the scope other than the focuser which has been sloppy since purchased new last year. My question is, is this scope really a super apo? It has the best color correction of any triplet I have owned but I have not owned too many. The design is well published so I am hoping perhaps Rolando will comment on what one can expect from this design. here is a link showing the design:
Posted 10/27/2008 07:56AM #1
Please send the scope to us and I will have Fred adjust the focuser for you.

Posted 10/27/2008 08:45AM #2

The combination of BSL7 and FPL53 provides almost ideal color correction over a wide wavelength range. BSL7 is essentially the perfect mate for FPL53. It cannot be used in doublet form unless you go approximately F12, however in triplet form (2 BSL7 with one FPL53 in the middle) one can make it as fast as F7. This design is the same as the one I used in the AP 160F7.5 EDF refractors. The design has to be airspaced, it cannot be an oiled triplet.