STARTEST IMAGES GALLERY

 Refractor130_01

Type: Apochromatic Triplet
Aperture: 130 mm
Focal length: 910mm (f/7)

startest Images copyright
Markus Ludes (c) 2001

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Inside Focus

Inside Focus

Outside Focus

Outside Focus

This is a new 4-lens design Apo. It has 4-lenses in the front cell (no petzval). The front pair is
oilspacest, rear pair is oilspacest and the center is airspaced. The used lightbeam was a bit tilted.  Thats why you get too much light on right side and to littke on the left side. That even makes it look a bit like coma, which is not visible under real skies.  When I have more time,I will shoot better images.

The lens is slightly undercorrected, but with a green filter it is nearly fully corrected at the eyepiece.
The Ronchi images confirm this. The lens show a smal central zone, which is also visible on the testreport.
 
The testreport datas from a radial shearing interferometer at 632.8 nm say:
Strehlratio 96.9%
wavefront p.t.v. 1/6.62
wavefront RMS 1/35.7

Markus Ludes (APM-Telescopes)
Collimator : 9" F/9 Triplet Super ED TMB Apo / Ronchi 254 lines/inch

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