Meade 10" LX850 f/8 ACF Advanced Coma-Free Telescope

Best for viewing:

Fainter deep sky
Best for imaging:

Deep sky
User level:

User level

Beginner Level - Suited for a wide range of uses, these products are simple to operate and set up. Some initial assembly may be required depending on the type of product. Optical instruments with this rating will have very good optical and mechanical quality. Great for families, young people, and folks who don't want to mess with equipment and complexity. Beginning level telescopes will show you countless lunar craters, Saturn's rings and a myriad of star clusters and nebulae! Referring to the manual is recommended.

Intermediate Level - These products offer higher performance and more advanced features than Level 1: Beginner models. They typically take a bit longer to learn and need some set-up or adjustments. But anyone with the slightest technical bent will have no problem getting familiar with these models. Referring to the manual is recommended.

Advanced Level - These products provide the best performance but may require more skill to master and appreciate. Optical instruments with this rating have exceptionally fine optics and mechanics. Some are easy to use but might be on the large or heavy side. Some are intended for specialized uses. These products will appeal to the more technically inclined. Referring to the manual is highly recommended.

Advanced
Optical design:

Optical design

Reflector telescopes use a pair of large and small mirrors to direct incoming light to the eyepiece. Refractor telescopes refract, or "bend" incoming light to a focus by means of an objective lens. Cassegrain telescopes, such as Maksutov-Cassegrains, "fold" incoming light using two mirrors and a front "corrector" lens.

Advanced Coma-Free (ACF)
Optical diameter:

Optical diameter

For telescopes, the optical diameter (also known as aperture) is the size of a telescope's main light-collecting lens or primary mirror, measured in millimeters or inches. Telescopes with larger optical diameters collect more light, which leads to an increase in brightness and image resolution compared to smaller instruments.

For binoculars, the optical diameter (also known as objective lens diameter) is the size of each of the front-facing objective lenses of a binocular measured in millimeters. Binoculars with larger objective lenses collect more light, which increases image resolution and brightness. Binoculars with larger objective lenses are recommended for low light situations, and binoculars with at least 50mm or larger objective lenses are recommended for pleasing astronomical observations at night.

254mm
Focal length:

Focal length

The distance from the center of a curved mirror or lens at which parallel light rays converge to a single point. The focal length is an inherent specification of a mirror or lens and is one of the factors in determining resultant magnification for a telescope (along with the focal length of the eyepiece being used).

2032mm
Focal ratio:

Focal ratio

The focal ratio of an optical system is the ratio of a telescope's focal length to its aperture. Short focal ratios (f/5, f/4.5) produce wide fields of view and small image scales, while long focal lengths produce narrower fields of views and larger image scales.

f/8.0
Magnification with included eyepieces:

81x
Resolving power:

Resolving power

The theoretical resolving power of a telescope can be calculated with the following formula: Resolving power (in arc seconds) = 4.56 divided by aperture of telescope (in inches). In metric units, this is: Resolving power (in arc seconds) = 116 divided by aperture of telescope (in millimeters). Note that the formula is independent of the telescope type or model, and is based only upon the aperture of the telescope. So the larger the telescope's aperture, the more it is capable of resolving. This is important to keep in mind when observing astronomical objects which require high resolution for best viewing, such as planets and double stars. However, it is usually atmospheric seeing conditions (not the telescope) which limits the actual resolving power on a given night; rarely is resolution less than one arc-second possible from even the best viewing locations on Earth.

0.46arc*sec
Lowest useful magnification:

Lowest useful magnification

Lowest useful magnification is the power at which the exit pupil becomes 7mm in diameter. Powers below this can still be reached with the telescope to give wider fields of view, but the image no longer becomes brighter at a lower power. This is due to the fact that the exit pupil of the telescope (the beam of light exiting the eyepiece) is now larger than the average person's dark adapted pupil, and no more light can fit into the eye.

36x
Highest useful magnification:

Highest useful magnification

The highest practical limit is different from the often used "highest theoretical magnification" specification. The "theoretical" limit generally is 50x the aperture of the scope in inches (2x the aperture in mm). So for example, an 80mm refractor is capable of 160x, and a 10" telescope is theoretically capable of 500x magnification. But after approximately 300x, theory breaks down and real world problems take over. The atmosphere above us is constantly in motion, and it will distort the image seen through the telescope. This effect may not be noticeable at lower powers, but at higher powers the atmosphere will dramatically blur the object, reducing the quality of the image. On a good night (a night where the air above is steady and the stars aren't twinkling), the practical upper limit of a large telescope is 300x, even thought the theoretical limit may be much higher. This doesn't mean the scope will never be able to reach those higher "theoretical" powers - there will be that rare night where the atmosphere is perfectly still and the scope can be pushed past it's practical limit, but those nights will be few and far between.

300x
Highest theoretical magnification:

508x
Limiting stellar magnitude:

Limiting stellar magnitude

The limiting stellar magnitude is a measure of the faintest star you can see through the telescope.

14.7
Optical quality:

Optical quality

"Diffraction Limited" means that the limits of image detail are determined by the physical properties of light, and not by optical defects in the telescope.

Diffraction limited
Finder scope:

8x50
Focuser:

Internal
Diagonal degrees:

2" 90° Mirror Star
Secondary mirror obstruction by diameter:

21%
Secondary mirror obstruction by area:

21%
Mount type:

Equatorial
Astro-imaging capability:

Astro-imaging capability

The astro-photographic capability of the telescope is based on the style, stability, and accuracy of the mount and tripod. Telescopes on either very lightweight mounts or non tracking mounts (such as Dobsonians) are capable of only very short exposures such as lunar photographs. If a motor drive is attached to an equatorial mount, even a small lightweight mount is capable of capturing some planetary detail. Larger EQ mounts that utilize very precise tracking and excellent stability are capable of longer exposure deep-sky photography.

Lunar, planetary & long exposure
Dovetail bar system:

Dovetail bar system

A universal attachment system for holding the optical tube onto the tripod. A dovetail bar is attached to the tube rings, then it slides onto the mount itself, making for quick assembly and disassembly.

Yes
Computerized compatibility:

Computerized compatibility

Some mounts are compatible with a motorized Go-To system for fully automated computer finding of objects in the night sky. Others mounts are compatible with computer finding systems which require the user to manually move the mount to the object's position as indicated by the computer finder.

Go-To included
Number of objects in database:

144,000
Tracking rates:

Sidereal
Motor speeds:

.01x to 1x, 2x, 8x, 16x, 1/4°, 1/2°, 1°, 3°
Motor type:

DC Servo motors with encoders
Power requirement:

12-volt DC - 5A (tip positive)
PEC:

PEC

Periodic errors are inherent in almost all worm gears due to slight eccentricities and misalignments. PEC (Periodic Error Correction) training function provides a manual correcting method to reduce the amplitude of the worm gear errors. By recording a full cycle of guiding actions, the mount can compensate for drifting in the R.A. sidereal tracking caused by periodic errors. The PEC training function is recommended for advanced users with interest in long-exposure astrophotography only. Standard sidereal tracking is sufficient for all casual visual applications, and PEC training is not required. Also, PEC is typically not used in conjunction with an autoguider.

Yes
GPS:

GPS

A GPS module automatically sets the date and exact time and location for the mount, relieving the user from the need to look up coordinates on a map or manually enter perfect time. This can be very beneficial when traveling with the scope as locations can quickly be automatically entered into the hand control.

Included
Backlash compensation:

Yes
Setting circles:

Electronic, via the hand controller
Polar-axis scope:

Not available
Counterweights:

Two 26 lb.
Available ports:

Available ports

Ports allow the mount to connect to devices such as autoguiders (for long exposure photography without tedious manual guiding), PC's running planetarium software (via the RS-232 port) and GPS receivers (through the Aux port).

RS-232, Aux, autoguider
Tube material:

Aluminum
Tripod material:

Aluminum & Steel
Tripod leg diameter:

3.00 in.
Counterweight bar length:

12 in.
Diameter of counterweight shaft:

45mm
Weight, optical tube:

33.0 lbs.
Weight, mount/tripod:

96.0 lbs.
Weight, fully assembled:

181.0 lbs.
Additional included accessories:

Series 5000 2" mirror star diagonal, Brackets for alternate OTA Starlock mounting
Other features:

StarLock automatic guider, LX850 mount with a payload capacity of up to 90lbs, Internal zero-shift Crayford style focuser
Warranty:

Warranty

This warranty gives you specific legal rights. It is not intended to remove or restrict your other legal rights under applicable local consumer law; your state or national statutory consumer rights governing the sale of consumer goods remain fully applicable.

Two year

User level

Optical design

Optical diameter

Focal length

Focal ratio

Resolving power

Lowest useful magnification

Highest useful magnification

Limiting stellar magnitude

Optical quality

Astro-imaging capability

Dovetail bar system

Computerized compatibility

PEC

GPS

Available ports

Warranty