The Swan eyepieces are super wide angle designs with a 72° apparent field of view. They use simple but sophisticated five-lens optical systems for generally higher contrast than the more complicated optical designs used in some other super wide angle eyepieces that use up to eight lenses. All lenses are fully multicoated for high light transmission. Lens edges and internal field stops are blackened to reduce internal reflections and improve contrast. The eyepiece rubber grip ring is useful for safer handling of the heavier 2" eyepieces in cold weather when wearing gloves. The eyepieces have soft roll down rubber eyecups for eyeglass use. They can be used for all types of observing, with all telescope types, but they are recommended for use with focal ratios up to f/6 and above. Dust caps are provided for both ends of each eyepiece. A soft protective drawstring-equipped velvet storage bag is standard equipment with each.
This 5-element super-wide angle 40mm SWAN EP's panoramic views at 72 deg. FOV will leave you speechless! A premium eyepiece at a fraction of the cost its worth!
Super Wide FOV
Outstanding super-wide field of view: 72 deg. FOV
Fully Multicoated lenses for excellent transmittance.
Reduced chromatic aberration.
Improved contrast compared to similar EPs.
Internally fully blackened (lens edges and internal spacers).
No flaring or ghosting on high-contrast objects.
Light and Easy
Soft rubber eyecup.
Extremely Long eye-relief: 28mm.
No internal reflections, kidney beaning or other distracting distortions.
Terrific Fit and Finish
High-resistance anodized black barrel.
Smooth design for no hook up in your focuser.
Threaded for use with 2" filters.
Nov 14, 2017
Works wellPros: Cons: Comments:
I use it in my 80mm and 127mm refractors. Solid and works well for wide field. I don’t have any other 2” 40mm eyepieces to compare it with, but I shopped for quite a while before settling on this one. I have only one other 2” eyepiece which is 32mm from another manufacturer, and the 40mm certainly gives a wider view of the skies. I recommend it without reservation, and especially from Agena. They do a good job of describing their items and they ship fast.
This review was provided courtesy of AgenaAstro.comMar 20, 2017
A Fine Piece of GlassPros: Cons: Comments:
I've been looking to get the widest FOV possible out of my SCT. I read up on the limits of apparent FOV for a 2" ocular at long FLs and the 40mm at 70 degrees is right around the limit.
All I want from an eyepiece is pretty good at a decent price, it seemed this one would fill the bill from the reviews I'd read. I'd seen one used but it was snapped up, so I splurged and went new. I just got my first chance to use it and I like it a lot.
It's true, at F10 and lucking into a 21.7 night, the conditions were almost too optimum, but none the less I think it's a keeper for sure. I had M81/82 in view with change, and the Leo Trio clearing all edges (if not by much on one side ;) ). The Virgo cluster was everything I wanted and more. That's pretty good for 2500mm FL on the scope.
Eye placement is super friendly and easy. Pretty good relief, the eye cup may also fold down but I didn't try it. The field is pretty flat and the noticeable aberrations don't start until the very fringes of the field.
I like it, it's a very nice piece and I'm glad I bought it.
My only gripe - in the diagonal I was using the fit was too close to 2". I'll have to try another diagonal. All I know is I had to have it lined up absolutely perfect to get it in, and even then it's a spin and wiggle operation to get it down. Every time. None of my other 2er's are like this, not even the green label. Not my favorite in the dark.
This review was provided courtesy of AgenaAstro.comSep 6, 2014
Good solution for deep skyPros:
Easy to Use,Wide View,Strong ConstructionCons: Comments:
It has a good quality/price rate and a good solution for very fine views of Moon and deep sky. I uses it with a cpc 800.
This review was provided courtesy of AgenaAstro.com
rmscott59 New Member
- Skill Level
- Time with Product
Jan 25, 2014
- User Notes:
- Review by RMS of San Francisco, CA.
Quality Lenses,Lightweight,Strong Construction,Easy to UseCons: Comments:
I wanted a wide field 2" EP that would frame M45 and other expansive constellations and this fit the bill EXACTLY!! I have used other 40mm-56mm EPs, and this WO 40mm BLOWS THEM AWAY!! Absolutely NO blackout or kidney-beaning...just tack-sharp views and great contrast!! You do get a tiny bit of softness at the very edges....but the view is so broad and expansive you don't notice or care unless you're really looking for it!! FANTASTIC EP!!
This review was provided courtesy of AgenaAstro.comJan 28, 2013
Great on SCT, not as much on fast scopePros:
Easy to Use,ValueCons:
I have had both this eyepiece and the William Optics 33mm for a couple months and this one has become one of my favorites on my C-11. Nice wide fields and vivid image.
On my 8" f/5, it's not as good. There is a fair amount of coma showing, so much that I will not use this eyepiece on that scope. So if you have a fast scope, you may want to keep shopping.
This review was provided courtesy of AgenaAstro.comFeb 25, 2012
Excellent wide-angle eyepiecePros:
Strong Construction,Quality Lenses,Easy to UseCons: Comments:
Excellent wide-angle eyepiece for the price. Objects appear bright. Field of view is wide enough to make the lens a pleasure to use.
This review was provided courtesy of AgenaAstro.comSort by
Apparent Field of View 72° Barrel Size 2" (50.8mm) Bolt Case Included Yes - Free Agena Eyepiece Container Bolt Case Size Agena 65x120mm Coatings Fully Multi-Coated End Caps 2 Eye Relief by Design 28mm Filter Threads Standard 2" Filter Thread (M48 x 0.75) Focal Length 40mm Lens Elements 5 Lens Groups 3 Parfocal Yes Blackened Lens Edges Yes Manufacturer William Optics Eyepiece Focal Length 30.1mm - 40mm Eyepiece Field of View 71 - 80 degrees Eyepiece Series William Optics SWAN Barrel Type Tapered barrel Eyepiece Weight 20.11oz (570g)