Telescope Summary

This table gives the focal length and other key specifications for each telescope.

Scope Focal Length Aperture Inches Aperture MM F Weight Kg
GSO 8" RC 1,625 8 203.2 8 7.5 *
North Group ED127 950 5 127 7.5 9.97
AT8IN 800 8 200 4 9.8
Maxvision MN152 740 6 152 4.8 6.9
WO Megrez 72FD 432 2.8 72 6 2.7
AT12IN 1200 12 300 4 20

* With 2" extension tube, OAG and guide camera attached

Previous scopes: Celestron Nexstar SE8

Camera Summary

The following table details the sensor and pixel size for each camera.

Camera Chip Type Sensor Size mm Resolution Pixel Size µm
Nikon D50 Sony ICX413AQ DX 23.70 x 15.60 3,008 x 2,000 7.8
QHY5 Micron MT9M001 1/2 6.66 x 5.32 1,280 x 1,024 5.2
Philips SPC900NC Sony ICX098BQ 1/4 4.6 x 3.97 659 x 494 5.6
Canon 500D   APS-C 22.3 x 14.9 4752 x 3168 4.7
QHY9 KAF-8300   17.96 x 13.52 3326 x 2504 5.4
STL-11000M C2 KAI-11000M   36 x 24.7 4008 x2672 9

Field of View

Field of view in degrees and arc minutes. Some of the data in this table was measures by Astrometry and the remainder was calculated from the approximation formula (source: Digital SLR Astrophotography by Michael A. Covington, page 59)

FOV (degrees) = 57.3 * Sensor Size (mm) / focal length (mm)

Scope Nikon D50
Arc Min
QHY5
Arc Min
Philips SPC900NC Arc Min Canon 500D
Arc Min
QHY9
Arc Min
STL-11000M Arc Min

STL Guider
Arc Min

GSO 8" RC 50.43 x 33.53 14.09 9.73 47.18 38.8 x 29.1 71 x 47* 10.37
AT12IN           102 x 68*  
AT8IN 102 28.62 19.77 95.83 77.18 154.71 21.06
ED127 84.71 x 56.33 24.10 16.65 80.70 65.00 126 x 85* 17.73
MN152  110.11 30.94 21.37 103.60 83.44 167.25 22.77
Megrez  188.61 53.00 36.61 177.47 142.93 286.50 39.00

Arcseconds per pixel

  Camera
Scope Nikon D50 QHY5 Philips SPC900NC Canon 500D QHY9 STL-11000M STL-11000M Guide Chip
GSO 8" RC 1.00 0.66 0.89 0.60 0.69 1.14 0.95
AT12IN           1.60  
AT8IN 2.03 1.34 1.80 1.21 1.39 2.32 1.92
ED127 1.71 1.13 1.52 1.02 1.17 1.89* 1.62
MN152 2.20 1.45 1.95 1.31 1.51 2.50 2.08
Megrez 3.76 2.48 3.33 2.24 2.58 4.29 3.56

 

Skywatcher EQ6 Pro

This mount was purchased with astrophotography in mind. It is in fact a standard EQ6 that has had the stepper motors, board and hand controller upgraded. That's why it's black and not the standard white color.
The mount has 3 modifications since I purchased it.

The most significant one is to use EQMOD instead of the hand controller.

Secondly I have reduced the noise it was making while slewing.

The other modification was to add a Geoptik saddle plate to allow the imaging and guiding scopes to be mounted simultaneously.

Williams Optics Megrez 72 Doublet APO

I acquired this scope in September 2009. It's a very solid looking scope with beautiful CNC machines parts. I use this scope for imaging and guiding. The retractable dew shield does a great job keeping dew off the objective lens. As an imaging scope, I found that stars in the corners tended to be elongated, radiating out from the center of the image. This seems to have been fixed to a large degree by a Williams Optics 0.8 Reducer/Flattener II.

Contact me.