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PW's web pages - Astro equipmentreviews

Pentax 75 Vixen VC200L ASA N8 Takahashi FSQ TeleVue NP101 Takahashi E-160 JSO LS-12 Megrez 80 Intes MK-67 Bresser Champ
Vixen GP-DX Losmandy G11 OTE 150 EQ-6 Vixen GP





Note: Except the Bresser Champ and the Intes MK-67 I used all telescopes exclusively for photography, so I can nothing say about visual performance.

Pentax 75    APO Astrograph 75/500 mm f6.7 (2006/12 - now)   

Translation is coming soon. Look at the german page.


Vixen VC200L    Cassegrain Astrograph 200/1800 mm f9 (2006/11 - now)   

Translation is coming soon. Look at the german page.


ASA N8    Newton Astrograph 200/560 mm f2.8 (2006/6 - 2009/4)    photo

Translation is coming soon. Look at the german page.


Takahashi FSQ    APO Astrograph 105/530 mm f5.0 (2004/12 - 2007/1)    photo

Translation is coming soon. Look at the german page.


TeleVue NP101    APO Astrograph 101/540 mm f5.4 (2004/7 - 2004/12)    photo

Translation is coming soon. Look at the german page.


Takahashi Epsilon 160    Newton Astrograph 160/530 mm f3.3 (2002/8 - 2005/1)    photo

Translation is coming soon. Look at the german page.


JSO LS-12    Japan Special Optics Wright-Newton 125/475 mm f3.8 (2001/11 - 2004/2)    photo

Never heart of a Wright-Newton? "The most interesting is rather rare, but very promising optical scheme called Wright-Newton. In this optical scheme the primary mirror is aspheric and has asphericity opposite to the parabolis mirror (deviation of the surface from a sphere is the same as for a parabolic mirror but the direction of the deviation is opposite). To correct the spherical aberration of such mirror, an aspheric plate is used. Such a combination completely eliminates coma, and, the most interesting, it flattens the field. Focal surface is completely flat. It is especially good for imaging. Geometric spot sizes are much smaller than diffraction disk, so star images will be exactly diffraction-limited." - Dmitry Makolkin (silverstar.pccenter.ru/fov.htm)
I got this exotic scope especially for astrophotography and I exchanged it for the Megrez 80. With f3.8 you can take astrophotos with very short exposure times. Unfortunately this astrograph was modyfied for visual observation by the previous owner and so I had to build a new focuser/adapter for the camera.
The JSO are no longer produced as far as I know. The first owner was incidentally Mike Palermiti, then it was at Sternwarte Hohenkarpfen.
Photographically it was a very good telescope with pinpoint stars to the edge of the 35 mm format. Light falloff to the edges was present but no problem with flatfields. Focusing with the R&P-focuser was a pain but it was easier with the selfmade Helical-focuser for the 35 mm camera.

William Optics Megrez 80SD    Achromat 80/480 mm f6.0 (2001/7 - 2001/11)    photo

This scope has the same diameter as the Bresser Champ and is also a achromatic refractor but plays in another league for price and performance. Furthermore I wanted a 2" focuser for photography. Anyway I have never seen such a beautiful and well finished instrument. Also the enclosed equipment is complete: Tube with retractable dewcap, 2" Crayford focusser (rotateable), 2" mirror diagonal, adapter 2"-1.25", tuberings and carrying case.
But I was disappointed by the optics. There was much astigmatism. Also the photos showed blue fringes, typical for achromates. William Optics would have exchanged the scope but this would have taken a view weeks and with f6.0 it was photographically to slow for me and so I exchanged it for the JSO.
Details see at William Optics.


Intes MK-67    Mak.-Cas. 150/1800 mm f12.0 (2000/6 - 2007/4)    photo

I got the scope used, together with the Vixen GP mount. First light was on 6/22/2000 at 23:00 (not astronomical dark) under very bad conditions (28°C, watching from the garden south of Vienna/Austria with heavy light pollution, bad seeing because of haze). Nevertheless the result was astonishing: The globular cluster M13 was partly resolved and filled half of the field of vision of the 15 mm Ploessl, ring nebula M57 was clearly visible (no improvement by the UHC-filter), Alcor/Mizar (Zeta UMa) was a wonderful triplet in the 25 mm eyepiece. Since then some time has gone and I am very satisfied with the telescope. It is mechanically solid (although I transported it often I never needed to adjust ist) with excellent optics. I use it mainly for photographing the moon and the planets with the webcam.
The MK-67 is labeled with 150/1500, a measurement with the Baader/Celestron Micro Guide Eyepiece resulted in a focal lenght of 1770 mm.
Pros: Excellent optics, no mirror-shifting because of a fixed mirror and a 2" Crayford-focuser, for photography nearly the whole 35 mm format is illuminated, very compact and robust metal tube and with 6 kg not too heavy, handle at the tube, secondary mirror is adjustable, carrying case is included.
Cons: The scope needs a long time to cool down (up to 1.5 hours in winter), the focuser has a focusing range of only 38 mm, 33% obstruction by the secondary mirror (nevertheless very good contrast), because of the f-ratio f12 the scope is nearly useless for deep sky photography, 6" is the lower limit for deep sky observation, the finder is too close to the tube and the thin cross hair lines are not illuminated and therefore nearly invisible at night.
Details see at Intes. A description of the previous owner can be found here as well as a test report by Ed Ting and a test report by Jay Reynolds Freeman.

Bresser Champ    Achromat 80/400 mm f5.0 (1999/12 - 2004/6)    photo

My first "telescope".
The new name is Bresser Everest. It is also sold as Vixen New Planet 80S, Celestron 80, Orion ShortTube 80, and others. It is very compact and the optical and mechanical quality is OK. The 1.25" focusser is from metal and fixable and has a T2-thread for a camera adapter. The optics shows the Cassini-division on Saturn and the two main cloudbelts on Jupiter. With reservation it can even be used for photography. I normally use it on a photo tripod for a short view to the sky before I go to bed.
Details see at Bresser.

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Vixen GP-DX Mount    (2003/6 - today)   

Translation is coming soon. Look at the german page.


Losmandy G11 Mount    (2007/6 - 2008/9)    Foto

Translation is coming soon. Look at the german page.


OTE 150 Mount    (2003/6 - 2004/8)    Foto

Translation is coming soon. Look at the german page.


EQ-6 Mount    (2001/12 - 2005/5)    photo

Translation is coming soon. Look at the german page.
Details see at Sky-Watcher.

Vixen GP Mount    (2000/6 - 2004/8)    photo

I got the mount used, together with the Intes MK-67. Added was the RA-motor and a fine polar finder with illumination. The mount is a little bit shaky for the long focal length of the MK-67. The reason is the aluminium tripod. But it's perfect for shorter focal length and even astrophotography with telelenses.
Details see at Vixen or Vehrenberg.




More tests and reviews of my equipment are coming soon ...


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