Inside Focus

Inside Focus

Outside Focus

Outside Focus

“This telescope uses a quarzmirror with a higher quality than usual. On the images there are some contrast problems. If we are able to solve these problem we will repost new images. To our own wondering the CCD- images are showing slightly different pictures than what the eyepiece shows. The real C.O. is around 20% but again in these images the central obstruction is larger due to the collimator-secondary. The optics are very smooth and are of the same quality as the 7" Quarz MN used in 2000 on WSP 2000, that got the very best startest notes”

Markus Ludes (APM-Telescopes)

“This simulation was done on the 2nd image from the left. The two outer rings are properly simulated but the inner-ring and the artifical shadow is not simulated good. Part of this is probably due to the slightly distorted nature of the original image on the left (indentation, skew). Using the amounts of LSA/HSA combined a total wavefront error of 0.131 (1/7) PTV and 0.03 (1/33) RMS can be expected. The PTV looks different from the Zygo-test but the simulation was done at 555nm and the Zygo-testing at 632nm. Therefore the errors at 555 are theoretically at least 632/555 = 1.14 times higher. Which makes the difference between the simulation and the Zygo-results definitely smaller.”

Cor Berrevoets