The Pages of The Gray Wizard

My Equipment

My Equipment
Solar System
Milky Way
Deep Skies

My Astronomy Equipment
My Bout With Aperture Fever

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[click on thumbnails for larger images]

My First Telescope (Tycho)
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tycho.JPG (27933 bytes)Meade ETX-90/EC Astro Telescope.

This highly portable 90mm Maksutov-Cassegrain Reflector got me started in this hobby.  Because of its portability, Tycho is still the first scope I grab for a quick lunar or planetary observation session.

Tycho is configured with:

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Autostar Computer Controller

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Meade Deluxe Field Tripod

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Meade Electric Focuser

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Meade 8X25mm Right-Angle Finder

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Dew Shield

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Rigel QuikFinder

Some Links

Have a question about the ETX, post it here:
ETX Mailing List
Sky and Telescope Magazine review
A "Hot" Telescope Gets Even Hotter
Astronomy Magazine Review
Meade Instruments Corporation

My Second Scope (Copernicus)
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celestron.JPG (22641 bytes)Celestron 8" Starhopper Dobsonian.

Missing all the wiz bang computer control of the ETX, Copernicus, an 8-inch Newtonian Reflector on a Dobsonian mount, is a basic light-bucket providing enough aperture to go beyond planetary observation into the realms of deeper space.

Copernicus is configured with:

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Telrad Reflex Finder


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Lasermax Laser/Holographic Collimator/p>

Some Links

Sky and Telescope Magazine review
Six 8" Dobsonians
Astronomy Magazine review
Sizing Up the Starhopper
Small Dob Website
Celestron International

My Newest Scope (Galileo)
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galileo.jpg (32482 bytes)Celestron CG-11 

Couldn't resist picking up this behemoth at auction.  Galileo is a 11" Schmidt-Cassegrain Reflector on a Losmandy German Equatorial Mount, by no stretch of the imagination a portable scope, but the large aperture promises some thrilling deep-sky observations.  Unfortunately, its large aperture also make it extremely susceptible to light pollution and so is most useful only under dark skies.

Galileo is configured with:

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Losmandy G-11 German Equatorial Mount

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G-11 Tripod

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Celestron Polar Finder with Illuminator

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Telrad Finder

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Orion FlexiShield Dew Shield

Celestron 7X50 Finderscope


Clutch knob set

Some Links

[Sky and Telescope review of the CG-11]
The Celestron CG-11
[Company Seven review of the CG-11]
Impressions of the Celestron CG-11 Telescope
[Amateur Astronomer's Notebook Review]
Celestron CG-11 Telescope
Rene Goerlich's CG-11 Site
Celestron International

My Binoculars

fujinon.jpg (5640 bytes)Fujinon 10x70 FMT-SX Polaris suregr~1.jpg (8943 bytes)Virgo Sure/Grip Binocular Holder
sky1.jpg (23393 bytes)Virgo SkyMount Parallelogram Mount 190_itm_img.gif (5584 bytes)Bogen/Manfrotto 3001 Tripod
Binocular Specifications
Magnification Objective
FOV Eye Relief
Exit Pupil
Max Width
10x 70 5°18' 12 7.0 244 285 2.16


Meade Eyepieces

Celestron Eyepieces

26mm LP Series 4000 Super Plossl

26mm Plossl

15mm Super Plossl

25mm SMA Wide Angle

9.7mm Super Plossl

7.5mm Ultima Series

5mm Ultima Series

Orion Eyepieces

Scopetronix Eyepieces

Optilux 2" 50mm
(not yet in service)

40mm Plossl

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Lasermax Laser/Holographic Collimator

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TeleVue 8mm-24mm Zoom Eyepiece

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Sky Atlas 2000.0 Star Charts


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Meade 2X Telenegative Barlow Lens

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Meade 2X Short-Focus Barlow Lens

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Nikon CollPix 990 Digital Camera


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Orion Variable Tele-Extender

Planned Purchases

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450 LOMO Binocular Viewer


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SkyWindow Binocular Mount


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9X60 Finder with illuminated reticle (for Galilieo)

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2" Diagonal
(to put my 2" Optilux 50mm in service - will undoubtedly spark purchases of additional 2" eyepieces) 

Dew Management System (for Galileo)

Narrow-band HII Light Pollution Filter

#8 Yellow Filter

#23A Light Red Filter

#38A Deep Blue Filter

#56 Light Green Filter

#80A Light Blue Filter

#58 Green Filter 

Variable Polarizing Filter

And if I can talk my wife into it:

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SkyTent Portable Observatory


The Power Myth

When visitors see my telescopes they invariably ask the question, "How much does it magnify?" or "What's its power?"  However, unlike fixed magnification binoculars, the power of an astronomical telescope depends on the eyepiece being used.  Power is a function of the fixed focal length (the distance from the objective to the focal point) of the telescope divided by the focal length of the eyepiece. The power of such a telescope can be varied by exchanging the eyepiece.  By using increasingly smaller focal length eyepieces, the power of any telescope can be increased almost indefinitely.  However, "useable" power cannot be increased without limit.  As the size of the image increases with increased magnification, the image becomes fainter and fuzzier.  What is important, therefore, is the resolution of the original unmagnified image.  This resolution is dependent on the light-gathering ability of the the telescope which in turn is a function of its aperture (the diameter of its objective lens or primary mirror). Contrary to the popular misconception therefore, the most critical characteristic of an astronomical telescope is not its power or magnification, but its aperture or light-gathering ability.  

Power Matrix

The following are rules of thumb for estimating Low, Medium and High Power limits for a telescope of given aperture.

Low Power .3 - .4 times the aperture in mm
Medium Power 1.0 - 1.2 times the aperture in mm
High Power font face="verdana, Arial, Helvetica">2.0 - 2.5 times the aperture in mm

NOTE: Magnification above 300X will only be useful under excellent atmospheric conditions

Here are the power configurations for my telescopes and my current set of eyepieces.

  Tycho   Copernicus   Galileo


 Meade ETX-90/EC Celestron 8" Dobsonian Celestron G-11 SCT


90mm=3.5" 203mm=8" 279mm=11"
Focal Length 1250mm 1220mm 2800mm
Maximum Magnification 360X 812X 1116X
Useful Magnification 180X 406X 558X
Low Power 27X-36X 61X-81X 84X-112X
Medium Power 90X-108X 203X-244X 279X-335X
High Power 180X-225X 406X-508X 558X-698X


Mag w/Barlow   Mag w/Barlow   Mag w/Barlow
40mmfont> 31X 62X 30X 60X 70X 140X
26mm 48X 96X 47X 94X 108X 215X
25mm 50X 100X 49X 98X 112X 224X
15mm 83X 167X 81X 163X 187X 373X
9.7mm 129X 258X 126X 252X 289X 577X
7.5mm 167X 333X 163X 325X 373X 747X
5mm 250X 500X 244X 488X 550X 1120X

Zoom Eyepiece

Mag w/Barlow   Mag w/Barlow   Mag w/Barlow
24mm 52X 104X 51X 102X 117X 233X
16mm 78X 156X 76X 153X 175X 350X
12mm 104X 208X 102X 203X 233X 467X
8mm 156X 313X 153X 305X 350X 700X