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Pentax SMC XW 20mm Eyepiece (1.25")

BH #PEEP20X • MFR #70516
9 reviews
Pentax SMC XW 20mm Eyepiece (1.25")
Key Features
  • For Select Pentax Spotting Scopes
  • For Telescopes That Use 1.25" Eyepieces
  • Wide 70° Angle of View
  • Low-Dispersion Lanthanum Glass Lenses
Compatible with their PF-65 and PF-65 ED II series, PF-80 series, and PF-100 series spotting scopes plus just about any telescope that accepts 1.25" eyepieces, the Pentax SMC XW 20mm Eyepiece produces a low magnification that provides a wide field of view, whether you use it for astronomical or terrestrial subjects.
In Stock
$269.00
$45/mo. suggested payments for 6 Mos.
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Focal Length
3.5mm
5mm
7mm
10mm
14mm
20mm
16.5mm
23mm
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Pentax 70516 Overview

Compatible with their PF-65 and PF-65 ED II series, PF-80 series, and PF-100 series spotting scopes plus just about any telescope that accepts 1.25" eyepieces, the Pentax SMC XW 20mm Eyepiece produces a low magnification that provides a wide field of view, whether you use it for astronomical or terrestrial subjects.

Using low-dispersion lanthanum glass with a six elements in four groups lens configuration and antireflection multicoatings, views through the eyepiece are crisp and bright with high resolution and minimal distortion. The spacious 70° field of view and exceptional 20mm eye relief ensure maximum comfort for long-duration use.

UPC: 027075075245

Pentax 70516 Specs

Focal Length20mm
Apparent Field of View70°
Eye Relief20.0 mm
Eyepiece Barrel Diameter1.25"
Field Stop Diameter24 mm
Dimensionsø: 2.4 x L: 3.4" / ø: 6.1 x L: 8.64 cm
Weight12.88 oz / 365 g
Packaging Info
Package Weight1.17 lb
Box Dimensions (LxWxH)7.4 x 3.95 x 3.5"

Pentax 70516 Reviews

Outstanding Optics Built to La

By Oliver
Rated 5 out of 5
Date: 2022-01-09

Fantastic optics and mechanics. Long eye relief a huge plus. Very flat field and no visible CA.

An exceptional eyepiece

By Doug
Rated 5 out of 5
Date: 2018-09-03

Took my recently acquired Pentax SMC XW 20mm eyepiece out for its first light recently with my 6-inch SCT. Conditions were not ideal as the skies were not particularly transparent due to smoke and passing clouds from a combination of monsoon flow and western US wildfires. Still, this eyepiece was a noticeable step up compared to the 25mm Plossl I had been using. During moments of good viewing, stars and planets were bright and sharp with no noticeable color aberration. The wide field of view and generous eye relief were especially nice. The only negative is some slight field curvature in the outer third of the field of view even though my SCT has a focal ratio of f10. With faster telescopes, the field curvature may be more of a concern. But again the 70 degree field of view is so much more expansive than my Plossl eyepieces that when a planet or DSO was centered, this was quickly forgotten.

Just right

By swix
Rated 5 out of 5
Date: 2015-06-23

I use this eyepiece on my LB-12 telescope.

Pentax Rules!

By Anonymous
Rated 5 out of 5
Date: 2014-09-03

This is a great all around eyepiece! Sharp images and high quality with a great warranty. I tried it in my spotting scope during the day for bird watching and it gave me a great widefield image. Forget the zooms especially in hot climates you will get too much mirage, this is the eyepiece to use for nature lovers everywhere! At night it doubles as a superb widefield astronomy eyepiece that will give you detailed images of nebulas, star clusters, and galaxies. Put a barlow on it and you have a great planetary eyepiece for high magnification. If you only have room for one eyepiece this is the one to get. And B&H shipped fast and was very reasonable. This eyepiece uses a standard size for many spotting scopes and telescopes which gives it versatility. The long eye relief is great for eyeglass wearers and it is very comfortable to use in long viewing sessions.

great all around eyepiece

By rbs
Rated 5 out of 5
Date: 2013-05-19

I bought this scope and the 20mm eyepiece for target shooting. It offers excellent optics, great field of view, and long eye relief. It is the perfect eyepiece for this scope, exceptional glass.

Decent match for pf 80ed spotting scope

By Anonymous
Rated 4 out of 5
Date: 2011-06-10

A decent all round match with the 80mm pentax spotting scope but if higher magnification is needed to see small things like leg band colors on birds a higher magnification would be recommended.

Clear and bright

By Tomas
Rated 5 out of 5
Date: 2020-09-04

I use this eyepiece mostly for birding. Unlike eyepieces with a zoom, this eyepiece provides clear and bright looks at the birds with a wide field of vision. I had been using a 14 mm lens on my Pentax spotting scope, but have found that this is a nice upgrade in terms of reach.

First Rate Eyepiece

By Damon
Rated 5 out of 5
Date: 2019-04-10

Use only for astronomy.  Fantastic optical quality:  sharp, bright, outstanding contrast.  As reported by others, shows some mild field curvature at field edge in my 6 inch f/10 SCT but isnt bothersome.  Cleans up nicely with a 0.63x focal reducer/corrector or with a 2x barlow.  Gives 2mm exit pupil with my scope, useful for viewing a great variety of celestial objects.   Fast shipping as always from B&H.

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question

i have a range of spotting scopes and have just bought a televue 85 scope i want to see the birds clearly that my 82 leica 65 leica and 65 vanguard can't at long range so this eyepiece only gives me the same as them am i correct in that ?
Asked by: Anonymous
The will have the same issue at long range: that any scope has trouble looking sideways through atmospheric turbulence beyond 40-60x. So....you are correct there. Laminar flow over smooth surfaces helps: I can see seabirds a mile away over the ocean. There may be times of day and weather when you can see better. Looking up (astronomy) has much less disturbance..
Answered by: James
Date published: 2021-11-23

I have a Pentax 65 ED II spotting scope and ...

I have a Pentax 65 ED II spotting scope and Pentax SMC XW 10mm eyepiece. If I wanted a greater field of view, should I get a bigger eyepiece 20mm or smaller one 5mm?
Asked by: Leonard
Magnification in telescopes and spotting scopes is calculated by division. So a 20mm eyepiece will have a greater angle of view than a 10mm or 5mm.
Answered by: John
Date published: 2022-11-02

question

is this eyepiece good for long range birdwatching?
Asked by: Anonymous
You will want more power (ie, lower focal length eyepiece) and calm weather (horizontal viewing can be turbulent at long range). 60x at 150 yds is only a little wavy,,,,,60x at 1 mile can get messy.
Answered by: James
Date published: 2021-11-23
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