Celestron Accessory Kit Amazon Price: $114.73
Customer Review: Really cool kit to enhace the real power of any mid-range telescope. Good quality lenses. Superb filters!...What else must I write?...Uhmmm...what are u waiting for?!!! you won't r...
Celestron 93230 8 to 24mm 1.25 Zoom Eyepiece Amazon Price: $51.95
Customer Review: I purchased this for my Nexstar 6se based on the price and Celestron name. For general viewing this is a good zoom eye piece for the price. I used it to zoom into the moon and Satu...
The Perfect Machine: Building the Palomar Telescope by Ronald Florence Amazon Price: $16.50
Customer Review: The book is well researched and documented.
I found the writing captivating only in some parts, while other parts were a bit dry.
Overall a good book that in my opinio...
How to Make a Telescope ( Second English Edition) by Jean Texereau Amazon Price: Customer Review: I have read many books on how to build telescopes and this is by far the best book to own! I thought that the "the dobsonian telescope by David Kriege" was an excellent book until ...
The capacity of a telescope to focus light is dependant on many features
such as the aperture, magnification, focal length and ratio, not to mention wave error and
resolution. These are the important features to bear in mind when purchasing a
telescope. Purchasing quality telescope is important as it vastly improves the quality of the
images and pictures you will produce.
Basically, an aperture is a hole or an opening through which light is admitted. But more importantly
an aperture determines the quality of the light waves admitted into the telescope. The narrower the aperture
the sharper, but darker the resultant image maybe.
Thus the aperture relates to the telescopes ability to focus light. The focusing also depends on the
size of the lens or mirror. The bigger the lens used, the brighter the image.
Aperture is hugely important, but bigger isn’t always best, so take other
features into consideration, too.
Magnification depends on a variety of things namely the lenses and distance to
the eyepiece. As a
guide, 40-60x per inch of aperture is sufficient. Low
magnifications give the best light in most cases.
Focal length. The longer the focal length - the distance the light travels from the
lens to eyepiece, the higher the magnification. Focal length is not the same as
the length of the telescope. Rather, it is the optical length of the telescope's lens.
Compound telescopes actually fold the path of the light making the optical length
longer than the length
of the tube. Eyepieces have focal lengths, also (typically between 4-50mm). To calculate a telescope's
magnification power,
you divide the focal length of the telescope by the focal length of the eyepiece.
Focal ratio tells you the relative brightness and field of view. The focal ratio is defined as
the relationship between the focal length and the aperture. A 10-inch scope with the focal length of
100 inches would have the focal ratio of 10. This would be expressed as f/10 or f10.
Similar to cameras, the lower the focal ratio the faster (brighter) the optical system. Lower focal
ratios have gentler curve to their optical elements and produce less optical aberrations.
F/10 and above
is for viewing the moon, planets and stars. F/8 meets most general purpose
requirements and F/6 and below is for viewing far distant objects.
The wave error gives you a measurement of the the quality of the mirror or lens in the
telescope. A wave error occurs when the light's wavelength is shifted or othe distortions occur.
The wave error is epxressedas a fraction and the smaller the number, the more perfect the quality.
The overall rating number for a telescope
represents the accumulated wave error numbers of each lens or mirror; an absolute minimum is
one-fourth. A wave error of 1/4 is typical of many mass-produced telescopes.
Resolution. The better resolution that a telescope has the better the clarity of the details
of the images. Resolution also reflects the telescopes ability to separate
two close objects - say two moons of Jukopitor whose orbits are crossing.
Buy Land on the Moon from The Lunar Registry makes a great gift!
Includes personalized deed, actual satellite property photo and
a detailed information sheet. Please click here to learn more!
Lowell lens nearly done Arizona Daily Sun The University of Arizona College of Optical Sciences is putting the final touches on an ultra-thin mirror that will be a crucial part of a new telescope...
The Irish Times - Friday, March 5, 2010 Irish Times That's where the Applied Optics Group comes in. Images picked up by such a sensitive telescope can be subject to distortion due to a phenomenon known as ...
Innovative deformable mirror for Palomar Observatory SPIE Newsroom More directly, the minute temporal evolution of quasi-static aberrations 4 arising from thermal and gravity changes in the telescope optics, AO instrument, ...
Galileo in a spin The Guardian A physicist in Kentucky, Christopher Graney, has worked out what Galileo could actually see through his telescope. He points out that the stars themselves ...
Exclusive pictures from the European Northern Observatory Astronomy Magazine (blog) One of the telescopes there, the Gran Telescopio CANARIAS (GTC), is currently the world's largest optical telescope. Along with the note, he sent the superb ...
DARPA wants razor sharp optics for satellite surveillance Washington Technology ... to fund a new program that would develop a diffractive optics membrane and related equipment and structures for use in a geosynchronous orbit telescope. ...