CELESTRON FIRSTSCOPE 90 AZ POWERSEEKER TELESCOPE

MODEL 21084 TRIPOD AND EXTRAS

SIGHT HAS BROKE BUT EASY REPAIR AS A CLEAN CRACK

IN MINT CONDITION

Product Description

CELESTRON FIRSTSCOPE 90AZ POWERSEEKER TELESCOPE

The Celestron Firstscope 90AZ is an achromatic refractor telescope well suited for high-power terrestrial observing, and it's easy to use for casual astronomy as well. This telescope uses the same optical tube as Celestron's Firstscope 90EQ, but the alt-azimuth mount and erect image diagonal are optimized for daytime use. The erect image diagonal means you won't see images that are upside down or mirror reversed which is common with telescopes designed for astronomy.

The alt-azimuth mount included with the Firstscope 90AZ is lighter and easier to use than an equatorial mount. The slow motion controls move the telescope up and down (altitude) and left or right (azimuth). Although designed for terrestrial use, I find the alt-az mount works pretty well for astronomy, too. There's no counter weight to balance or polar axis to align, just point the telescope and look.

As soon as I get the moon or a planet centered in the eyepiece, it starts drifting toward the edge. This is caused by rotation of the Earth. The slow motion controls make it easy to track stars and planets for fifteen or twenty minutes at a time. Because it can't track stars and planets with a motor, this telescope is not suitable for time exposures of deep-space objects, but I had no trouble using a Celestron Neximage to take some nice closeups of the moon and sunspots. (Always use a safe solar filter for viewing the sun!)

Two eyepieces are included as standard equipment. The 20mm Kellner magnifies the image by 50x and takes in about 0.8 degrees of sky, enough to take in the full moon. The 10mm Kellner yields 100x magnification for good close up views of Lunar craters, Saturn's rings or the moons of Jupiter. These eyepieces have a narrower field of view than popular Plossl eyepieces; in fact my favorite eyepiece with this scope is a 32mm Omni plossl (31x magnification) which almost doubles the field of view compared to the 20mm Kellner.

The best telescopes for astronomy will be larger to gather more starlight; check out the telescope buyers guide for some examples. The best spotting scopes will be more portable and have a wider field of view. But no telescope in this price range can handle both tasks any better than the Firstscope 90AZ. Celestron's Firstscope 90AZ proves to be a competent crossover telescope that delivers real performance by daylight and by night. --Jeff Phillips

Pros:

Good day and night viewing

Durable, low maintenance design

Easier to use than equatorial mounted scopes Cons:

Narrow field of view

Does not track stars and planets

Too small for deep-space viewing

From the Manufacturer

This high quality altazimuth refractor is an excellent choice for the more serious beginning astronomer or terrestrial observer. It's a powerful optical instrument with over 130 times the light gathering ability of the naked eye. This ability allows the FirstScope 90 AZ to deliver images 78 percent brighter than those produced by a 60mm refractor telescope. The objective lens is designed to yield the finest images available in this class of optical instrument. The accessories for this telescope are all made of glass with metal construction, to ensure good image quality.

These telescopes have all glass components, coated optics and smooth functioning mounts, with the added benefit of slow motion controls on the mount for easy adjustments. The FirstScope 90 telescope tubes are glossy black aluminum.

The altazimuth mount is easy to use and has slow motion controls on both the axes. These controls are on flexible cables, to allow for quick and easy pointing and tracking.

When used for astronomical viewing, this telescope yields breathtaking views of the moon, Saturn with its ring structure, Jupiter and its belts, and hundreds of deep-sky objects including: galaxies, nebulae and star clusters. Add an optional solar filter and you can observe activity on the sun. For terrestrial use, you can enjoy views from your own backyard or take your telescope out in the field to enjoy the natural environment, up close.

Aperture: 90mm (3.54")

Focal Length: 1000mm (39")

Focal Ratio: f/11

Focal Length of Eyepiece 1: 20mm (0.79")

Magnification of Eyepiece 1: 50x

Focal Length of Eyepiece 2: 10mm (0.39")

Magnification of Eyepiece 2: 100x

Finderscope: StarPointer™ red dot finderscope

Star Diagonal: 1.25 Erect Image

Mount Type: Altazimuth

Accessory Tray: Round, Thread-in

Tripod: Aluminum

Highest Useful Magnification: 213x

Lowest Useful Magnification: 13x

Limiting Stellar Magnitude: 12.3

Resolution (Rayleigh): 1.55 arc seconds

Resolution (Dawes): 1.29 arc seconds

Light Gathering Power (Compared to human eye): 165x

Apparent Field of View: 0.8°

Linear Field of View (@1000 yds): 42 ft (13 m)

Optical Coatings: Multi-Coated

Optical Tube Length: 1016mm (40")

Total Telescope Kit Weight: 19 lbs (8.62 kg)

IDEAL FOR ALL