How To Buy A Telescope : How To Buy Eyepiece For Telescope
Saturday, February 13th, 2010 at
10:19 am
What qualities to look for in a telescope eyepiece and what to avoid. Learn more tips for buying a telescope this free home astronomy equipment video from a telescope designer and manufacturer.
Ex...
US $19.88
Thank you…
Rating: 0 Posted By: rts Views: 3 Replies: 0 I was looking for some basic moon filter, 2x Barow and couple of eye pieces (32mm etc.) and found that they are selling the entire kit with almost all eyepiece and filter combos for 100 bucks! A great value for any telescope owner. I’m sure, if I buy these things separately, I’ll have to shell out 300+ bucks (not that I will actually do that). You can use it with smaller telescopes like the Celestron Firstscope on Fatwallet few days back .. all the way to much bigger professional ones. Zhumell is a pretty solid company and has gotten a good reputation in the astronomy forms …Here are the details:The Zhumell 1.25 Inch Eyepiece-and-Filter Kit includes:- 4mm high-grade eyepiece- 6mm high-grade eyepiece- 12.5mm high-grade eyepiece- 32mm high-grade eyepiece- 2x Achromatic Barow Lens- #12 Yellow filter- #21 Orange filter- #23A Light Red filter- #56 Green filter- #82A Light Blue filter- Polarizing filters- Chrystalview Moon filter-…
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Ummm I suggest you go and get yourself exactly what you want… a telescope
I have a JASON and it works great for me. Less than $200 I think, good luck.
Discount Sony Alpha Eyepiece Cup for the Alpha Series DSLR Digital Cameras
Useful aussie store if your thinking of buying a telescope or pair of binoculars.
u look ugly like that lmao
What is the distance between the eyepiece and the inverting lens?
You have given that
The inverting lens and eyepiece are 5.08 cm apart.
Correct your question.
Useful aussie store if your thinking of buying a telescope or pair of binoculars.
Optical Features
The telescope's ability to collect light is directly related to the optics that are used. Telescopes with poor quality optics can be very frustrating to use. Here are some optical considerations to think about when buying a telescope:
Aperture
Magnification
Focal length
Focal ratio (f/number)
Wave number
Resolution
Aperture
The telescope's ability to collect light is directly related to the size (diameter) of the objective lens or primary mirror. Generally, the bigger the lens or mirror, the more light the telescope collects and brings to focus, and the brighter the final image. Aperture is probably the most important consideration when buying a telescope, but it is not the only consideration. You want to try to purchase as much aperture as you can reasonably afford; however, you should also consider other factors that will be discussed below, including size, weight, storage space and portability. The biggest telescope is not always the best one for you!
Magnification
This consideration is perhaps the most misleading to novice telescope buyers. Often, manufacturers of "cheap, department store" telescopes will display "200x power or more" on the boxes of their products. The magnification or power has little to do with the optical performance of the telescope, and is not a primary consideration. The telescope's ability to enlarge an image (magnification) depends upon the combination of the lenses used, usually a long focal length objective lens or primary mirror in combination with a short focal length eyepiece. As the magnification of an image increases, the field of view and the brightness of the image decrease. A general rule about magnification is that the telescope's maximum magnification is 40x to 60x (average = 50x) per inch of aperture. Since any magnification can be achieved for almost any telescope by using different eyepieces, aperture becomes a more important feature than magnification. Furthermore, most astronomical objects are best viewed on a low magnification or power to gather the most light possible.
Focal Length
Focal length is the distance required by the objective lens or primary mirror to bring all of the light collected to one point (the focus or focal point). The focal length of the lens or mirror is usually printed somewhere on the telescope's tube; if not, it should be found in the instructions or on the box. The focal length is an important number to know. As discussed above, magnification depends upon the focal length of the objective lens or primary mirror and the focal length of the eyepiece. Generally, long focal length telescopes are capable of delivering higher magnifications than short focal lengths. However, do not mistake the length of the telescope tube for the focal length, because compound telescopes have a folded light path, which delivers a long focal length in a short tube.
Focal Ratio (f/number)
Focal ratio or f/number relates to the brightness of the image and the width of the field of view. The focal ratio is the focal length of the objective lens or primary mirror divided by the aperture. The focal ratio concept comes from the camera world, where a small focal ratio means a short exposure time for the film, and was said to be "fast." Although the same is true for a telescope, if a "fast" and a "slow" telescope are compared at the same magnification for visual rather than photographic viewing, then both telescopes will have the same quality image. Generally, the following information about focal ratios can be helpful:
f/10 or higher – good for observing the moon, planets and double stars (high power)
f/8 – good for all-around viewing
f/6 or lower – good for viewing deep-sky objects (low power)
Wave Number or Wave Error
No glass lens or mirror is perfect! The wave number or wave error is an indication of how well the mirror or lens was ground compared to an ideal surface. This number is probably listed in the instrument's specifications, somewhere in the instructions (it is never prominently displayed, so you may have to ask the dealer or manufacturer). Wave numbers are expressed as fractions of a wavelength. The smaller the wave number, the better the mirror or lens. While the absolute minimum acceptable wave number is one-fourth, good telescopes generally have wave numbers of one-eighth or less. Also, the overall performance of the telescope is an accumulation of the wave errors of each optical component. For example, a telescope with two mirrors (each with a one-eighth wave number) will have an overall wave error of one-fourth.
Resolution
The ability to see fine detail in an image of the moon, a planet or a double star depends upon how well the telescope can separate, or resolve, two close objects. Resolution depends upon the aperture of the telescope, the quality of the optics, and the observing conditions (e.g. light-polluted vs. dark, dry vs. humid atmosphere). Generally, the ideal limit, also called the Dawes limit (arc-seconds), is 4.46/aperture in inches or 116/aperture in millimeters
4000/26
Thank you for this review.
How to Buy a Telescope : Binoculars Vs. Telescopes
Dammit I've got to figure out how to make enough spare dough to buy me a telescope
Useful aussie store if your thinking of buying a telescope or pair of binoculars.
Eyepiece-gog?.
1:46 wtf!! haha….anyway,very useful video,thanx!
http://www.analyticalsci.com/
but only if you are seriously into astronomy otherwise you find the same quality in walmart as you do in academy.
What the? Is that a bullethole in your hand? You are so gangsta, bro!!
Any quality telescope with a sturdy german equatorial mount equipped with a motor drive will do, or a telescope with a sturdy motorized fork mount and wedge.
The important thing is, the mount is of good quality. There are other factors to consider, such as focal ratio and aperture and filters and such.
You should ask the best way to get started in the astrophotography formu on http://www.astromart.com
How to Buy a Telescope
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Rating: 0 Posted By: rts Views: 3 Replies: 0 I was looking for some basic moon filter, 2x Barow and couple of eye pieces (32mm etc.) and found that they are selling the entire kit with almost all eyepiece and filter combos for 100 bucks! A great value for any telescope owner. I’m sure, if I buy these things separately, I’ll have to shell out 300+ bucks (not that I will actually do that). You can use it with smaller telescopes like the Celestron Firstscope on Fatwallet few days back .. all the way to much bigger professional ones. Zhumell is a pretty solid company and has gotten a good reputation in the astronomy forms …Here are the details:The Zhumell 1.25 Inch Eyepiece-and-Filter Kit includes:- 4mm high-grade eyepiece- 6mm high-grade eyepiece- 12.5mm high-grade eyepiece- 32mm high-grade eyepiece- 2x Achromatic Barow Lens- #12 Yellow filter- #21 Orange filter- #23A Light Red filter- #56 Green filter- #82A Light Blue filter- Polarizing filters- Chrystalview Moon filter-…
The Bad Astronomer writes “As much as 90% of previously hidden galaxies in the distant Universe have been found by astronomers using the Very Large Telescope in Chile. Previous surveys had looked for distant (10 billion light years away) galaxies by searching in a wavelength of ultraviolet light emitted by hydrogen atoms — distant young galaxies should be blasting out this light, but very few were detected. The problem is that the ultraviolet light never gets out of the galaxies, so we never see them. In this new study, astronomers searched a different wavelength emitted by hydrogen, and voila, ten times as many galaxies could be seen, meaning 90% of them had been missed before.”
Read more of this story at Slashdot.
Rating: 0 Posted By: rts Views: 3 Replies: 0 I was looking for some basic moon filter, 2x Barow and couple of eye pieces (32mm etc.) and found that they are selling the entire kit with almost all eyepiece and filter combos for 100 bucks! A great value for any telescope owner. I’m sure, if I buy these things separately, I’ll have to shell out 300+ bucks (not that I will actually do that). You can use it with smaller telescopes like the Celestron Firstscope on Fatwallet few days back .. all the way to much bigger professional ones. Zhumell is a pretty solid company and has gotten a good reputation in the astronomy forms …Here are the details:The Zhumell 1.25 Inch Eyepiece-and-Filter Kit includes:- 4mm high-grade eyepiece- 6mm high-grade eyepiece- 12.5mm high-grade eyepiece- 32mm high-grade eyepiece- 2x Achromatic Barow Lens- #12 Yellow filter- #21 Orange filter- #23A Light Red filter- #56 Green filter- #82A Light Blue filter- Polarizing filters- Chrystalview Moon filter-…
Astronomical telescopes invert the image, because you don't care that a 'star' is upside down. The fewer mirror surfaces the light bounces off of, the less light is lost, the better.
Terrestrial observation telescopes do not invert the image (by adding an extra mirror to re-invert the image). You can always buy an astronomical telescope and add an image inverting mirror, too.
Hunters use small spotting 'scopes all the time. They have the inversion built into a prism inside the scope.
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how powerful does your telescope have to be to view an image of the sun like that, but instead of the sun, Centuri A?
Useful aussie store if your thinking of buying a telescope or pair of binoculars.
Time to do a little reading! This is one of the best resources I have found in selecting a good eye piece set. As my eyes have aged my needs have changed. Selecting wide field without coma is a challenged especially if you have a fast scope.
I hope this helps. It did help me.
HTH
Charles
nice:)
is that a blueberry
Rating: 0 Posted By: vks22 Views: 14 Replies: 0 Adorama has it for 764.90, excluding 3% BCB.Add to cart to see the low price, otherwise it says 846/-Nikon D5000 DX-Format Digital SLR Camera – 18-55mm f/3.5-5.6G VR AF-S DX NIKKOR Lens – 55mm – 200mm f/4-5.6G ED-IF AF-S DX VR NIKKOR Lens – EN-EL9a RechargeableLi-ion Battery – MH-23 Quick Charger – DK-5 Eyepiece Cap – DK-24 Rubber Eyecup -UC-E6 USB Cable – EG-CP14 Audio Video Cable – AN-DC3 Camera Strap – Body Cap – BS-1 Accessory Shoe Cover – Software Suite CD-ROM – Nikon 1 Year Limited Warranty LinkOnline Coupons