“This is a Maksutov Cassegrain 8"F/15. We have had the choice to take it or give it back to the producer for repolishing, because it did not completely reach the designers specifications of 1/8 wavefront p.t.v. and 1/50 wavefront RMS. During startesting it showed a very smooth surface and was estimated at about 1/6 to 1/7 (more towards1/7) wavefront p.t.v. This is why I took it home as an demonstration-model. Again the central obstruction is slightly increased due the larger secondary of the autocollimator” Markus Ludes (APM-Telescopes) |