Last updated: 24 October 1999

The following table (second draft) compares the specifications, features, and capabilities of the Meade ETX-125EC and the Celestron NexStar5. It is provided for informational purposes only and may contain errors. Some comments may be repetitive, subjective, or based on limited experience with a particular telescope or accessory. We have to trust that no inputs are based upon speculation or hearsay, but are instead based upon the manufacturer's published information or actual experience. Readers owning either the ETX-125EC or the NexStar5 are encouraged to submit additions, corrections, and/or clarifications.

Meade provided the "zeroth" draft of this table. I then edited the table for the first draft in the hopes of removing any bias. The inputs in RED are from Russ (russbag@yahoo.com). Inputs in GREEN are from Clive Gibbons (gibbonsc@mcmail.cis.McMaster.CA). Inputs in PURPLE are from Ken Hayes (khayes@powernet.net). Clarifications in BLUE are from Meade Instruments. All user supplied inputs are included verbatim.

Reviewing the table, writing inputs, and the merging of inputs is time consuming for all of us, but I thank those readers who have sent updates. Lets all work together to make this comparison as accurate as possible for the benefit of potential buyers.

Feature/Capability ETX-125EC NexStar5
Optics 127mm f15 (1900mm) Maksutov-Cassegrain 127mm f10 (1250mm) Schmidt-Cassegrain
High Contrast Baffling Moderate Contrast Baffling
Factory set collimation.  Must be returned to factory for adjustment. Factory set collimation.  Can be user adjusted.
Secondary mirror obstruction:as reported by Meade: 1.55". Actual obstruction: 2" Secondary obstruction reported and actual: 2".
EMC coatings: multicoated corrector, 90% reflectivity mirrors. Starbright coatings: Corrector, 95% reflectivity mirrors.
Baffling. Higher contrast baffling.
Optical Tube Assembly Anodized aluminum Painted Aluminum
Flip Mirror built into backcell All optical functions external
Proprietary accessory thread [Aftermarket adapter available.] Industry standard accessory thread
Focuser Micrometric, moving primary mirror. Focus knob/shaft mounted in sleeve bearing. Displays stiffness and roughness when turned. Micrometric, moving primary mirror. Focus knob/shaft mounted in dual race Ball bearing assembly for great smoothness and light action.
Viewfinder 8x 25mm right-angle, with 6 alignment screws 1x Red-Dot style with simple 2 knob alignment screws
poor eye relief, much off-axis distortion. Positioned to hit your nose when observing through the main optics. Easy to use. Long eye relief.
Mount Issues Fork type, double tine (Metal reinforced plastic) Fork type, single tine (Metal)
Spring loaded helical gear drives Spur gear drive
Variable tension locks on both axes for manual movement [Fixed tension lock on Altitude axis, No manual mode for Az.]
No manual adjustment in Alt or Az.
Power cord plug on stationary base Power cord plug on rotating base
Plastic gears Metal gears
Plastic stops on range of movement No limits on range of movement
OTA movement limted by base OTA can point in any direction
No storage provided for either controller Mount provides integrated controller storage
Fork type, plastic with metal inserts.
Cheap, insubstantial feel. Too flexible.
Solid aluminum with plastic skin.
Further southern Declination available in polar mode: -35 deg.
Fork arms: plastic. Fork arm: Aluminum.
Gears: plastics. Gears: metal.
Plastic gears in the reducer, but the last two gears are metal, namely the worm and worm gear.
- Range of motion severly limited when camera is attached to rear port - No limits on range of motion when a typical camera assembly is attached
- Planets & Moon: suitable - Planets & Moon: suitable
- Deep Space: not recommeded by manufacturer [but doable] - Deep Space: suitable
- Piggyback: aftermarket - Piggyback: aftermarket
Piggyback (using adapter). Piggyback (using adapter).
Brief exposures of Sun, Moon, and planets through optional camera adapter. Short and long exposures shots of celestial objects, Incl. Deepsky though the NexStar's main optics using available accessories.
Deep Sky Photography: No. Deep Sky Photography: Yes.
Pointing capability with camers: limited motion. Pointing capability with camera: no limits.
The ETX is limited in the Zenith but only when using the rear thread set. If the zenith is your target area the camera can be mounted in the eyepiece hole on the top using a basic camera adapter sold by Meade.
Controller EC Handbox (supports manual movement) [Nexstar]
Included controller supports manual and GoTo computer movement
Autostar (optional) GoTo computer included
Display 16x2 LCD 16x2 LCD
- Negative image - Positive image
- Transflective Display - Transflective Display
- Adjustable red backlight (16 levels) - One level
- Contrast function - No Contrast adjustment
- Heat sources placed near LCD for cold weather offset - Very little Heat produced in the handbox.
- Scrolling Text speed Adjustable - One speed
- Automatic Display power down when not used - Manual power down only
Keypad 20 Tactile Keys 19 Tactile Keys
- Negative image - Positive image
- Protective surface coating - No protection
- Adjustable red backlight (16 levels) - only One level
- Automatic backlight power down when not used - Manual power down only
Memory 1 Megabyte Flash Memory 256 Kbytes Eprom
User upgradeable using the RS-232 (Objects and software) Not user upgradeable
Serial Interface RS-232 Serial Port RS-232 Serial Port
- Always available - Must be turned on by menu option
- 115 operation commands. - 4 operation commands
- Object libraries and software download from PC - None
- Object libraries and software download from other Autostars - None
Handbox cord Coil Cord detachable at both ends Coil Cord detachable at one end
Control Panel Ports 12 Volt Power plug 12 Volt Power plug
Handbox Port None (handbox port is inside the fork arm)
On/Off Switch On/Off Switch
Two Auxiliary Ports for accessories (focuser & future). None
Utility Light Utility Light (red) None
Processors Four processors, 1 - 68HC11, 1 - PIC16C57, 2 - PIC16C54 Four processors, 2 - PIC17C44, 2 - 16C63
Audible Device Beeper to signal operator attention None
Menu Languages English, German, French, Italian, Spanish, Japanese English
Text/Descriptions Over 50,000 words of text for 442 objects, glossary and help text. Limited descriptions for over 100 objects
Scrolling Text Adjustable speed Fixed speed
Hypertext Hypertext links to text and hypertext GOTO to objects. No links
Help Functions Extensive help text & help Functions Limited
Motor Speeds Nine slew speeds from 2x to Full Power (5.4ƒ/sec) Nine slew speeds from 1x to Full Power (6ƒ/sec)
Speed changed using one key press Speed changed using two key presses
Power Consumption 90 mA (idle) 176 mA (idle)
110 mA (tracking) 190 mA (tracking)
220 mA (1 motor slewing) 390 mA (1 motor slewing)
330 mA (2 motors slewing) 600 mA (2 motors slewing)
Batteries 8 AA internal (bottom loaded) 8 AA internal (top loaded)
Battery Life 20 hours operation with intermittent slewing 5 hours (using demo mode)
Power Conservation Automatic power down of inactive subsystems None
Sleep function None
Alignment Adjustments Sync function Third Star function
Certifications FCC and CE certified No markings
Patents Pending (Design patent and Utility patents) No markings
Accessories Electric focuser accessory (integrated with handbox functions) [None]
Aftermarket accessory available (not integrated)
Ability to use SCT accessories: No. [Aftermarket adapter available.] Ability to use SCT accessories: Yes.
GOTO Function Automatic telescope slewing to selected objects Automatic telescope slewing to selected objects
Notification of Objects below the Horizon Will point at Objects below the Horizon
Automatic slewing to specific RA & Dec or Alt/Az Automatic slewing to specific RA & Dec or Alt/Az
Objects 15,642 total object designations (442 text descriptions) 18,473 total object designations (over 100 text descriptions)
Solar System 8 Planets with descriptions 8 Planets with descriptions
Moon with 8 descriptions (based on the current phase) [None]
New version of firmware shipping with newest scopes ( includes Moon
No Sun (omitted for safety purposes) Sun
26 Asteroids (can be edited, appended and erased) None
15 Comets (can be edited, appended and erased) None
Constellations 88 constellations with descriptions 20 Asterisms
Major stars listed for constellation with GOTO capability None
Deep Sky 13,235 Named Objects, Galaxies, Nebulas, Planetary Nebulas, 8,059 Named objects, NGC catalog, Messier catalog,
Star Clusters, Quasars, Black Holes, IC Objects, NGC catalog, Caldwell catalog
Caldwell catalog, Messier catalog.
Stars 943 total stars sorted as follows; Named, SAO Catalog, Double, 10,385 SAO catalog, Named, Double, Variable.
Variable, Nearby, Planetary Systems.
Satellite 50 earth orbiting satellites None
Alarm can be set for satellite rise time N/A
User Objects Up to 200 celestial objects and landmarks. Up to 20 celestial objects and 5 landmarks
Identify Function Will identify the object nearest to the center of the field of view None
Event Menu This menu gives the time and/or date for the following events; None
Sunrise, Sunset, Moonrise, Moonset, Moon Phases,
Meteor Showers, Solar Eclipses, Lunar Eclipses,
Minimum of Algol, Autumnal Equinox, Vernal Equinox,
Summer Solstice, Winter Solstice
Guided Tour Best available objects for viewing at the moment (above the horizon). Monthly tours (objects may be below horizon)
Planets and the Moon included Planets and Moon not included
All tour objects have extensive descriptions Minimal descriptions
Glossary Definitions of 97 astronomical terms, sorted alphabetically. None
Timer 24 hour timer, beeper sounds when expired. None
Alarm 24 hour alarm, beeper sounds at selected time. None
Eyepiece Calculation Computes the field of view and magnification and suggests None
the suggested eyepiece for the current object.
Brightness Adjust 16 brightness levels for the LCD and Keypad backlighting. Separate On/Off only for LCD and Keypad
Powered down display resumes with touch of any key N/A
Contrast Adjust 16 contrast levels for the LCD. (improves cold weather performance) None
Battery Alarm Audible alarm for low battery (last 10%). Disable option. None
Demonstration Mode Slews to all landmarks in sequence and pauses Demo slewing to random coordinates
Sleep Scope Places telescope in the lowest power mode and maintains time and None
alignment. Resumes operation with the touch of any key.
Park Scope Parks the telescope in a home position for power off. Operation None
can resume at power on and user entering time and date.
Alignment Polar or Altaz align using one star, two stars or Easy Align. Polar or Altaz align using two stars or Auto Align.
Automatic backlash compensation during alignment Alignment stars must be centered using up and right keys
Alignment can be done anytime from the menu [Must be done at power up or you will need to cycle the power]
Either alignment star can be replaced at any time.
Date and Time 12 Hour and 24 Hour format. 12 Hour and 24 Hour format.
Supports DST and time zone selection.
Telescope Model Defines multiple telescope system and capabilities [None]
Included computer supports NexStar 5 only
Telescope Focal length Used in eyepiece calculations. [None]
Not used by computer
Encoder ratios Permits definition of new encoder ratios [None]
Fixed encoder ratios
Backlash Training Precise backlash training for both axes using reference targets. User adjustable Backlash value between 0 & 100 for each axis.
Motor Calibration Permits automatic field calibration of motor/encoder system Factory calibrated
Tracking Rates Sidereal, Lunar or Custom. Sidereal, Solar, Lunar or King
Reverse slew keys Slewing direction for keys can be changed [None]
Automatically reverses direction keys at slew rates 6 and below for correct motion in the eyepiece.
High Precision Mode Improved pointing using intermediate reference star None
Tracking Mode/mount North and South Hemisphere Polar or altaz or no tracking. North and South Hemisphere Polar or altaz or no tracking.
Site 6 sites selected by name 10 sites selected by number
Automatic site entry from a catalog of 1285 worldwide sites None
Custom site entered manually or by editing cataloged entry Custom site entered manually
Owner Information Owner name and address. None
Statistics Displays the software revision and user memory available. [None]
Displays the software revision at power on.
Reset Resets the Autostar to factory default condition. None
Status Displays Displays current RA/DEC or Alt/Az of telescope Displays current RA/DEC or Alt/Az of telescope
Local time and Local Sidereal Time None
Current Date None
Current Site None
Timer (time remaining) & Alarm (time set) None
Battery level None
Focuser Display & operation None
Included Accessories
26mm Plossel eyepiece (73x) 25mm Plossel eyepiece (50x)
8x25 Right Angle Finder 1x Red Dot Finder
Manual controller only GoTo Computer
None AC Powersupply
Built-in Visual back & Mirror Diagonal

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