Does 62° differ from regular

Depends on what exactly "regular" means. An apparent field of view of 62° is more than what Huygens eyepieces (around 30-35°) and Kellner eyepieces (about 45°) have, the usual design for low-cost eyepieces such as those which are included with many beginner telescopes. Furthermore, 62° is also more than what Plössl and Super Plössl eyepieces (around 45-52°) offer, which are more expensive than Huygens or Kellner eyepieces and which are typically the first choice for better and yet affordable all-around eyepieces. On the other hand, 62° is slightly less than for Erfle eyepieces (around 65-68°, usually called WA for wide angle) and less than for ultra-wide angle eyepiece designs (anything beyond about 80°), both of which are more (WA) or much more (UWA) expensive than these aspheric eyepieces. From my point of view, these aspheric eyepieces mainly rival Plössls, as they have about the same optical quality with a larger apparent field of view for less money. They are no match for WA and UWA eyepieces, both in optical performance or price, and they easily outperform Huygens or Kellner eyepieces.

Is it plastic or metal

Hi Ken Wilson,the aperture of 4mm telescope eyepiece is aluminum alloy, and the mirror body is plastic, the lens is optical glass.hope this can help you!Sincerely Angela

What does the focal length mean on an eyepiece? I thought that was just for concave mirrors.

All eyepieces have a focal length and it is very important to know what it is and what it means. Being made of usually several lenses, the eyepiece will have a focal plane. That's where the eyepiece focuses on and examines the image formed by a telescope, for example. Usually the focal length is printed right on the barrel of the eyepiece in millimeters. The importance of this is that you can determine the magnification of your telescope by knowing the scope's focal length and the eyepiece focal length. Say you have a telescope that has a focal length of 500 mm. this would also likely be somewhere on the scope or in the instruction manual. The magnification of the telescope will be the focal length of the telescope divided by the focal length of the eyepiece. So if you have a 500 mm focal length telescope and use a 4 mm eyepiece, the magnification is 500/4=125X. Or if you use the same scope with an eyepiece that has a focal length of 10 mm the magnification will be 500/10= 50X. An eyepiece with a focal length of 25 mm gives a magnification of 500/25= 20X. So you can see the shorter the focal length of the eyepiece for a given telescope, the more power or magnification. But there are drawbacks to magnification. With higher magnification you get a narrower field of view, compared to lower magnification. Also, for a given scope there is a limit to the amount of magnification it will handle. Too much magnification and the image gets blurry or soft. Magnification is not the most important number when using a telescope. There's more to it, hope can help you!

Coating	Fully Multi-Coated
Focal Length Description	23 millimeters
Field Of View	62 Degrees
Finderscope	Reflex
Compatible Devices	astronomical telescopes with a 1.25 inch focuser
Eye Piece Lens Description	Kellner
Mount	Fixed Mount
Focus Type	Manual Focus
Item Weight	4.16 ounces
Exit Pupil Diameter	2.7 Millimeters
Objective Lens Diameter	62 months
Item Dimensions D x W x H	3.5"D x 5.23"W x 3.5"H

4mm 10mm 23mm Telescope Eyepieces Lens Fully Coated Lens Accessories Kit 62 Degree Wide Angle for 1.25 inches Astronomic Telescope

Details

Description

Specifications

Common Questions