25mm 1.25" Paradigm Dual ED

by Astro-Tech Print

What would you like to print?
(Reviews and Documents/Videos will not be printed)

Basic Product Information
Full Description
Tech Details
Supplied Accessories
Recommended Accessories
Images

Print
More product information
This Astro-Tech 25mm Paradigm Dual ED is an excellent medium to low power eyepiece for encompassing open clusters, picking up detail in emission and reflection nebulas while still viewing them in their entirety, etc. This high quality 25mm focal length optical gem will visibly upgrade the performance of the usually only so-so 25/26mm eyepiece that typically comes standard with most telescopes. It is also a good choice to complement the 40mm eyepiece provided with some go-to Schmidt-Cassegrains. The 25mm Astro-Tech Paradigm is usable with any telescope type, under virtually any seeing conditions – from fair to superb. (Rain, snow, or fog might limit its usefulness, however.)

With a short focal length refractor it is a low power eyepiece well suited to scanning the crowded star clouds of Sagittarius, observing galaxy clusters, framing the more compact emission nebulas with the black of space, observing the nebulosity around the Pleiades, etc. With the 430mm focal length f/6 Astro-Tech AT72ED, its six lens/four group two ED lens optics provide a magnification of 17x, a field nearly seven times as wide as the full Moon, and a 4.16mm exit pupil that is ideal for rich field observing.

The 25mm Astro-Tech Paradigm is also a good choice for medium power observing with long focal length refractors, reflectors, and catadioptric scopes. On an 8” f/10 catadioptric, for example, it yields 80x, with a 0.75° field that is half again as wide as the full Moon. This is a very useful magnification for observing compact planetary nebulas and globular clusters, as well as lunar observing. Its high contrast makes observing small features along the lunar terminator a nightly delight as the terminator creeps across the face of the Moon.

The six lens/four group design and two ED (Extra-low Dispersion) glass elements of the 25mm Astro-Tech Paradigm provides all of the optical virtues described at the top of this catalog page – high contrast, a sharp and flat field from edge to edge, excellent color fidelity, and exceptionally low astigmatism and barrel distortion. It has a usable eye relief of 15mm. Combined with the twist-up eyecup design, the good eye relief makes it a sensible choice for eyeglass wearers.

This new Astro-Tech 25mm Paradigm Dual ED eyepiece will upgrade your scope’s starter eyepiece, bringing new life to your nightly views of the heavens. The 25mm Paradigm will change your mind about just how good low power viewing with a telescope can be, with truly high-end optical performance at a not very high-end price.

Field of view:
The field of view (FOV) is the amount of observable world one can see at any given moment.
60°
Eye Relief:
Eye relief is the distance from the last surface of the eye lens of an eyepiece to the plane behind the eyepiece where all the light rays of the exit pupil come to a focus and the circular image is formed, sometimes called the “Ramsden Disk.” This is where your eye should be positioned to see the full field of view of the eyepiece. If you must wear glasses because of astigmatism, you’ll usually need at least 15mm of eye relief or longer if you want to see the full field of view with your glasses on.

A note on our eye relief figures: Quite often, our eye relief figures will differ from those of the manufacturer. This is because we measure the “usable” eye relief, while the manufacturers specify their usually-longer (but technically correct) “designed” eye relief.

The eye lens of the eyepiece is normally recessed below the rubber eyeguard or rubber rim of the eyepiece to keep the lens from being scratched during use. An eyepiece might have a “designed” eye relief of 15mm (and the eye relief will truly measure 15mm from the eye lens to where the image forms). However, if the eye lens is recessed 3mm below the eye guard, the Ramsden Disk forms only 12mm above the eyepiece body (the 15mm “designed” eye relief, less the 3mm of eye relief made unusable by having the eye lens recessed into the body of the eyepiece). This “usable” eye relief of 12mm (measured from the rolled-down eyeguard – the closest point you can get your eye to the eye lens – to where the image forms) is the eye relief figure we would measure and list in this website.

Why is it important to list the “usable” eye relief? For those people who don’t wear eyeglasses while observing, a few mm difference between the eye relief they expect from the manufacturer’s literature and the shorter eye relief they actually get in real life doesn’t mean a lot. They can simply move a little closer to the eyepiece to see the full field, and never realize that the eye relief is a little shorter than they expected. However, some people must wear eyeglasses while observing, because of severe astigmatism. These observers can’t move closer to the eyepiece if the eye relief is shorter than expected because their glasses get in the way. For these people, the real life “usable” eye relief is more important than the technically correct but sometimes not fully usable “designed” eye relief. We measure and list the actual usable eye relief so that people in the real world can pick the eyepieces that will work best for them.

15mm
Focal Length:
This is the length of the effective optical path of a telescopeor eyepiece (the distance from the main mirror or lens where the lightis gathered to the point where the prime focus image is formed). Focallength is typically expressed in millimeters.

The longer the focallength, the higher the magnification and the narrower the field of viewwith any given eyepiece. The shorter the focal length, the lower themagnification and the wider the field of view with the same eyepiece.

25mm
Number of optical elements:
6
Barrel Size:
The industry standard diameter, as of 2011, is 1.25" and is the most common.  Other sizes available are .965" and 2".
1.25"
Weight:
The weight of this product.
6.4 oz.
Warranty:
2 years
Reviews from Cloudy Nights (www.cloudynights.com)
These reviews have been written by astronomers just like you and posted on the Cloudy Nights astronomy forums . . .
First Look: Astro-Tech Paradigm Eyepieces

User Ratings/Reviews from our Customers (www.astronomics.com)
Overall Product Rating: AstronomicsAstronomicsAstronomicsAstronomicsAstronomics(4.50)   # of Ratings: 2   (Only registered customers can rate)

(Only registered customers can rate)

5 - Great (50.00%) (1 user)
4 - Good (50.00%) (1 user)
3 - OK (0.00%) (0 users)
2 - Bad (0.00%) (0 users)
1 - Very Bad (0.00%) (0 users)
0% 50% 100%
astronomics image
astronomics image

Sort Ratings: 

  Show these ratings: ALLGreatGoodOKBadVery Bad

loading request
Showing comments 1-2 of 2
1. Stephen on 5/15/2013, said: AstronomicsAstronomicsAstronomicsAstronomicsAstronomics
I bought one to test in my 8", f/7 Newt and the image was so sharp, with excellent contrast, that I tried it on another, smaller f/6 scope. Same results. I now own 5 different FL Paradigms and they are my "Go-To" eyepieces in all scopes of f/6 or longer. The edge sharpness is as good as center-of-field and the 60* AFOV is a big plus in any Dob. Eye relief on all Paradigms is good so I can avoid spending big $$ on expensive LER eyepieces.

I have "Big-Brand" eyepieces of $200+ each, and still prefer the Paradigms. The price is WAY under what you get in performance.
Was this comment helpful? Yes No   (7 people found this comment helpful, 0 did not)
2. Gregory on 4/30/2013, said: AstronomicsAstronomicsAstronomicsAstronomicsAstronomics
I've had the 25mm paradigm for about 5 months now. I wanted a maximum field of view eyepiece for my 1.25" focusers, and this one fit the bill perfectly. No ghosting, no false color, very forgiving eye placement (I do not wear glasses at the scope, so I have the adjustable plastic piece all the way up). My one optical complaint would be that it seems to have some field curvature -- when the stars in the middle of the view are in sharp focus, the ones at the outside have a little coma or astigmatism (I don't really know what to call it, they are stretched). But if you fiddle a while, you can get them all "pretty good." This is probably exacerbated by my f/5 fast scope. It is also a little bit too heavy for really small scopes (but it is fine in my StarBlast 6, for example). It is absolutely the first eyepiece I put in the telescope most nights, and the one I use for most of my star hopping. Sometimes when the field curvature gets on my nerves, I cycle back through my other 25mm/26mm eyepieces (a plossl and a budget apogee widefield) and it is absolutely no contest, the Paradigm is the best. It is basically as good as a plossl in the center of the view, and then it gives you a bunch of extra view without too many trade-offs.
Was this comment helpful? Yes No   (7 people found this comment helpful, 1 did not)
Showing comments 1-2 of 2
General Accessories
Accessory Cases (1)
52mm x 80mm eyepiece container
by Astronomics
Quantity:  
$3.49 
This product does not have supplied accessories... or supplied accessories have not been assigned.
Documents
No documents have been associated with this product.
Videos
Astro-Tech 25mm Paradigm Eyepiece
Helpful Formulas
Telescope Eyepiece Formula
To calculate the magnification and approximate actual field of view of this eyepiece on your telescope, enter the focal length of your telescope below and press the "Calculate" button.

Enter your telescope's focal length: mm   



Astro-Tech - 25mm 1.25" Paradigm Dual ED

Click icon(s) below & hover image above for zoom

Astro-Tech - 25mm 1.25" Paradigm Dual EDImage showing a typical Paradigm eyepiece with the twist-up eyecup in both the fully extended and fully retracted positions.
Wait List
 AstronomicsAstronomicsAstronomicsAstronomicsAstronomics (Average: 4.50 | Users: 2)  Only registered users can submit ratings - Register Here
Our Product #: ATPARA25
Price: $60.00  Ground shipping for this item is $8.95 - Click for more info
By adding 1 of these items to your cart your order total will be less than $100, and will ship within the 48 contiguous United States for $8.95. Add $40.00 to your order, however, and you qualify for free ground shipping (heavy items with fixed shipping, such as counterweights, excluded).
Quantity:   

 E-mail this product to a friend E-mail this product to a friend

Your Email:  
Your Friend's Email:  
Confirm Friend's Email:  

Comments:
  200 characters or less
 

An email containing a link to this product has been sent to the email address you provided.

Clear Skies!
Astronomics

 Have a question? Do you have a question about this product?
 Found a better price? Found a lower price? Click to let us know... or call 800-422-7876 before you buy.

If you’ve found a lower delivered price on this product, let us know about it below. We’ll do our best to meet or beat that price and will get back to you within one business day with our best offer. Thanks for giving us the opportunity to give you a better deal.

Your Name:  
Price:  
From Who:  
Context:  Magazine AdOnline
Website Address:  
Cut and paste the web address into the box above
Your Email:  
Confirm Email:  


We’ll do our best to meet or beat that price and will get back to you within one business day with our best offer. Thanks for giving us the opportunity to give you a better deal.

Clear skies,
Astronomics


This Astro-Tech 25mm Paradigm Dual ED is a medium-low to low power eyepiece that will visibly upgrade the views through your scope when compared with the standard 25/26mm eyepiece supplied with most new scopes . . .





. . . our 34th year