Telescope Reflectors

Telescopes are of two main types – reflectors and refractors. The rudimentary divergence amidst both types is the kind of glasses employed for light collection. Refractors use lenses while reflectors use mirrors. Going back to school physics, it is apparent that light from distant bodies, like celestial objects, comes at us as a parallel beam. Due to this parallel nature of the light rays, reflector telescopes use parabolic mirrors.

Such a parabolic mirror focuses each ray of light it receives from the original parallel beam at one single point. Because of this nature of the mirror, a reflector type telescope is far more beneficial in comparison to a refractor. A singularly indispensable point to be brought up is that reflectors do not suffer from chromatic aberrations which are a mutual problem for refractors. This is because, different from refraction which modifies the way in which dissimilar wavelengths are refracted, mirrors do not affect the wavelengths at all.

A second vantage is that they are comparatively less pricey for the same quality of magnification. Furthermore, since light is reflected, only the reflecting surface needs a perfective finish. In the case of refractors, light has to pass form one side of the lens to the other, as a result of which both refracting surfaces need to be utterly polished.

Astronomers in general prefer reflecting telescopes; however, even these have a lot of disadvantages. The most glaring of these is the difficultness faced in rectify alignment of the mirrors. Reflectors are equipped with an open tube, therefore the inner optical parts require regular maintenance and cleaning. Without this care, images formulated by the telescope end up blurred and indistinct. There are also instances of requiring secondary mirrors to correctly focus light at peculiar spots. These secondary mirrors may likewise adversely affect the effigy quality.

The major disfavor faced with both refractors and reflectors is that the final effigy is an inverted image. An easy solution for this fault is the placement of a relay or prism in the passage of light, so that an already inverted effigy reaches the eyepiece, which again inverts it to construct an erect image. This is because the relay or the prism as the case may be, acts as a light ray inverter resulting in a final upright image.

The above paragraphs mention the use of secondary mirrors in reflectors to modify the spot of light focus. These secondary mirrors are littler than the primary mirror. According to historical accounts, Sir Isaac Newton used a mirror that was flat and inclined at 45 degrees as a secondary mirror. The intention of this mirror was to shift the reflected light to an eyepiece at the side of the upper part of the tube. This arrangement is now known as the Newtonian design and still finds takers.

There is another special design used in reflector type telescopes known as the Cassegrain design. This gives the light from the subject a specific path to reflect it better on the primary mirror. With this design it is possible to position the eyepiece at one’s own convenience. Even modern telescopes like the great Hubble Space Telescope make use of this design, and for the vantages discussed above, astronomers lean towards the reflector, and not the refractor.

AstroMaster 130EQ – General Features

• Quick and easy no-tool setup
• Permanently mounted StarPointer
• Erect effigy optics – Ideal for terrestrial and astronomical use
• Quick release dovetail attachment – no tool setup
• German Equatorial mount with Setting circles – to accurately locate and track sky objects
• Rugged pre-assembled tripod with 1.25″ steel tube legs – Provides a rigid and stable platform
• All coated glass optics for clear, crisp images
• Deluxe accessory tray for commodious storage of accessories
• “The Sky” Level 1 planetarium software with 10,000 object database and intensified images

Details
If you’re looking for a dual-purpose telescope suitable for both terrestrial and celestial viewing, then the AstroMaster Series is for you. Each AstroMaster model is competent of giving rectify views of land and sky.

The AstroMaster Series manufacture bright, clear images of the Moon and planets. It is easy to see the moons of Jupiter and the rings of Saturn with each one of these fine instruments. For views of the more glorious deep space objects like galaxies and nebulae, we commend the more prominent aperture and light gathering capacity of the Newtonian reflectors.

Specs

• Optical Design: Reflector
• Aperture: 130 mm (5.12 in)
• Focal Length: 650 mm (25.59 in)
• Focal Ratio: 5
• Eyepiece 1: 20 mm (0.79 in)
• Magnification 1: 33 x
• Eyepiece 2: 10 mm (0.39 in)
• Magnification 2: 65 x
• Mount: CG-3 Equatorial
• Optical Coatings: Aluminum
• Weight: 28 lb (12.7 kg)
• Finderscope: Built-on StarPointer
• Tube Attachment: Dovetail Bar
• Star Diagonal:
• Tripod: 1.25″ steel tube legs
• CD ROM: The Sky L1
• Highest Useful Magnification: 307 x
• Limiting Stellar Magnitude: 13.1
• Resolution (Rayleigh): 1.07 arcsec
• Resolution (Dawes): 0.89 arcsec
• Light Gathering Power: 345 x
• Angular Field of View: 1.5 °
• Linear Field of View (@1000 yds): 79 ft (24.08 m)
• Optical Tube Length: 24 in (609.6 mm)

2-year Telescope Warranty

CELESTRON TWO YEAR LIMITED WARRANTY

A. Celestron warrants your telescope to be free from defects in materials and workmanship for two years. Celestron will fix or replace such product or portion thereof which, upon inspection by Celestron, is found to be defective in materials or workmanship. As a condition to the obligation of Celestron to repair or replace such product, the product must be returned to Celestron together with proof-of-purchase satisfactory to Celestron.

B. The Proper Return Authorization Number must be received from Celestron in advance of return. Call Celestron at (310) 328-9560 to receive the number to be displayed on the outside of your shipping container.

All returns will have to be accompanied by a written statement setting forth the name, address, and daytime telephone number of the owner, together with a brief description of any claimed defects. Parts or product for which substitute is made shall become the property of Celestron.

The client shall be responsible for all costs of transportation and insurance, both to and from the factory of Celestron, and shall be required to prepay such costs.

Celestron shall use reasonable attempts to repair or replace any telescope covered by this warranty within thirty days of receipt. In the event repair or alternate shall require more than thirty days, Celestron shall notify the client accordingly. Celestron reserves the right to replace any product which has been discontinued from it is product line with a new product of comparable value and function.

This warranty shall be void and of no strength of effect in the event a covered product has been modified in design or function, or subjected to abuse, misuse, mishandling or unauthorized repair. Further, product malfunction or deterioration due to normal wear is not covered by this warranty.

CELESTRON DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WHETHER OF MERCHANTABILITY OF FITNESS FOR A PARTICULAR USE, EXCEPT AS EXPRESSLY SET FORTH HEREIN. THE SOLE OBLIGATION OF CELESTRON UNDER THIS LIMITED WARRANTY SHALL BE TO REPAIR OR REPLACE THE COVERED PRODUCT, IN ACCORDANCE WITH THE TERMS SET FORTH HEREIN. CELESTRON EXPRESSLY DISCLAIMS ANY LOST PROFITS, GENERAL, SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES WHICH MAY RESULT FROM BREACH OF ANY WARRANTY, OR ARISING OUT OF THE USE OR INABILITY TO USE ANY CELESTRON PRODUCT. ANY WARRANTIES WHICH ARE IMPLIED AND WHICH CANNOT BE DISCLAIMED SHALL BE LIMITED IN DURATION TO A TERM OF TWO YEARS FROM THE DATE OF ORIGINAL RETAIL PURCHASE.

Some states do not grant the exclusion or limitation of incidental or consequential damages or limitation on how long an implied warranty lasts, so the above limitations and exclusions may not utilise to you.

This warranty gives you specific legal rights, and you may likewise have other rights which vary from state to state.

Celestron reserves the right to change or discontinue, without prior observe to you, any model or style telescope.

If warranty troubles arise, or if you need assistance in using your telescope contact:

Celestron
Customer Service Department
2835 Columbia Street
Torrance, CA 90503
Tel. (310) 328-9560
Fax. (310) 212-5835

Monday-Friday 8AM-4PM PST

NOTE: This warranty is valid to U.S.A. and Canadian clients who have purchased this product from an authorized Celestron merchant in the U.S.A. or Canada. Warranty outside the U.S.A. and Canada is valid only to clients who purchased from a Celestron’s International Distributor or Authorized Celestron Dealer in the specific country. Please contact them for any warranty service.

Telescope Reflectors Picture

Telescope Reflectors Photo

Telescope Reflectors Picture

Telescope Reflectors Photo

Most helpful client reviews

22 of 22 people found the following review helpful.
Celestron 130 review
By kands6191
I’m very pleased with this telescope. I’ve always looked up at the stars in wonder, now I may see more then I thought were out there. This is a outstanding starter scope, from what I’ve been told by persons who love this hobby. The telescope lets you view the sky to see stars you can’t see with your eyes. I’m disappointed in the eye piece you receive with it though. The field of view is very narrow, hard to find the stars you want to see. I was given a wide angle eye piece, to use from a friend, which made my watching pleasure wonderful. I went from looking at a 13″ color tv to a 36″ color tv. That’s the best way to describe it.

See all 18 client reviews…