Agena 1.25" ED Eyepiece - 3.8mm
Brand | Agena AstroProducts |
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Product Info
Manufacturer Description
ED stands for "Extra-Low Dispersion". These eyepieces use optical glass in which two of the lens elements are crafted from ED glass which is a special grade of glass that provides much superior refractive properties as compared to standard optical glass. This results in much better color correction. ED glass is often the type used in many expensive camera lenses and high-end refractor telescopes costing thousands of dollars.
Our ED-series eyepieces are available in a 1.25" barrel in 10 focal lengths (2.3, 3.8, 5.2, 7.5, 9.5, 12.5, 14, 18, 21 and 25mm). They feature a six-element lens design that provides significantly reduced chromatic aberration, high resolution and excellent sharpness without compromising image brightness. Their long 20mm eye relief means that even eyeglass wearers can take in the full 55-degree apparent wide field of view (AFOV).
All ED-series eyepieces are fully broadband multi-coated for maximum image brightness. Lens edges are blackened throughout for improved contrast. The eyepiece housing is precision machined from aluminum and clear-anodized to a lustrous finish. A rubber traction ring ensures a secure grip and a rubber eyeguard helps position your eye to block out stray light. The chrome barrel features a setscrew recess for added security. All eyepieces are parfocal and are threaded to accept standard 1.25" filters. Each eyepiece comes in a bolt case with two plastic end caps. Compare these with the ED eyepieces sold in very similar focal lengths by two of the "Big-3" telescope companies and you'll realize the savings we offer.
Important note: Depending on your telescope, this eyepiece may provide magnifications that are too high! While it can be very useful for viewing the Sun, Moon, brighter planets and terrestrial objects, it is not for everyone or for common viewing conditions.
Before buying, please make sure that you are using realistic magnifications with your telescope. A good rule of thumb is that under very good conditions and with a very good telescope, the maximum power you will be able to use is about 50x of magnification per inch of telescope aperture. With average telescopes and/or average conditions, you might be limited to 30x of magnification per inch of telescope aperture. So for example, if you have a 5" telescope, under typical conditions you might typically use 5x30 = 150x of magnification, and 5x50 = 250x of magnification at best. If your telescope has a focal length of, say, 1000mm, then this eyepiece will result in a magnification of 1000 / 3.8 = 263x which is probably too much for this telescope.
Also, when you magnify an object, its light is spread over a larger area. Since the brightness of the object being viewed hasn't changed, this means that the image you see will be fainter. Double the magnification and the image will get 4 times fainter. This is a basic law of physics, but people often forget this and complain that the "image is not bright enough" when they increase the magnification to very high powers.
Boosting the magnification beyond the recommended maximum for your telescope aperture is not realistic. This is bound to result in image break-down, causing faint, fuzzy images, focusing difficulties, increased color around objects and general disappointment. Use the eyepiece in the right settings and with the correct expectations, and you will enjoy it.
Reviews
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Oct 28, 2011
Great EP for the price
Pros:Quality Lenses,Easy to Use,Strong Construction,Lightweight
Cons: Comments:This eyepiece is great, I use it exclusively for planetary viewing with my 8" F/6 reflector, getting 315x which is just the right amount of power to see planets in nice seeing conditions. Construction seems pretty good, and to me, is very light considering its quite big size. Image is sharp and clear in most of the field of view, edges become distorted but c'mon this is not a $250 eyepiece, hence, this is a perfect budget planetary eyepiece.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Jun 5, 2011HD eyepiece 3.8mm
Pros:Very sharp planet view
Cons: Comments:I took this out the other night when the visibility was good here in Portland. I got clear views of the ring bands and cloud bands on Saturn. This ones good for planet observation. AgenaCraig
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
ApexMI_bob New Member
- Skill Level
- Unknown
- Time with Product
- Unknown
- User Notes:
- Review by ApexMI_bob of Algonac, MI.
Oct 15, 2009Very happy with my first results
Pros:Quality Lenses,Strong Construction
Cons: Comments:Very sharp eyepiece with excellent contrast. I've only had a couple nights out with it and am still getting used to the long 20mm eye relief. But I am very happy with this purchase and will be adding more Agena eyepieces to my collection.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
skooter60 New Member
- Skill Level
- Unknown
- Time with Product
- Unknown
- User Notes:
- Review by Skooter60 of Hatfield PA.
Mar 30, 2009Great Planetary EP
Pros:Quality Lenses,Strong Construction
Cons:Heavy
Comments:This was used in a F/5 reflector and F/5 refractor, the views are crisp and sharp. It also cut down on the CA I normally get when looking at bright objects. The eye releif is great and it just looks and feels like a quality EP.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Sort bySpecifications
Apparent Field of View 55° Barrel Size 1.25" (31.7mm) Bolt Case Included Yes - Manufacturer Supplied Bolt Case Size - Coatings Fully Broadband Multi-Coated Height (with Eye Guard) 5.0" (126mm) End Caps 2 Eye Relief by Design 20mm Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6) Focal Length 3.80mm Lens Elements 6 Rubber Eye Guard Yes Blackened Lens Edges Yes Manufacturer Agena AstroProducts Eyepiece Focal Length 5mm and Under Eyepiece Field of View 51 - 60 degrees Eyepiece Series Agena ED Barrel Type With safety undercut Eyepiece Weight 7.50oz (212.62g)