Pentax SMC-XL 40mm

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Brand and Model:Pentax SMC-XL 40mm
Price ($USD):$244.50
Type:Misc Wide Angle
Focal Length:40 mm
Barrel Size:2 in
Apparent FOV:65.0 degrees
Field Stop Dia.:0.0 mm
Eye Relief:20 mm
Elements:5
Weight (lbs):0.9
Description:

Vote Highlights Vote
Pentax SMC-XL 40mm
I bought this used for $215 US. It was well worth the price! In my 10" f4.8 dob w/ Paracorr, the stars are sharp out to the last 10% FOV. With this EP, I can fit M45 in the FOV! In my 3" f6.6 refractor, the stars are truly sharp. Baffling and construction are first rate. It is not too heavy. It makes for an excellent finder EP.

Overall Rating: 10
Optics:10 Value:9
Weight: 10 (Trustworthy Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=355042

Pentax SMC-XL 40mm
I have used this eyepiece on my 20", 10" & 8" newts. All of these scopes are F5.2 - F5.6. The stars are not perfect at the edge, but I prefer this eyepiece over the Panoptic 35mm because there is no noticable distortion as in the Panoptic. It is great to pan around with this eyepiece. I think one of the greatest strengths is the fact that the actual field of view it gives within my telescopes affords me the opportunity to utilize them as finders and look for my target at low power.

My Home Page

Overall Rating: 9
Weight: 7 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=42993

Pentax SMC-XL 40mm
A nice, big, heavy 2" bug-eyed eyepiece that shows large chunks of sky. For some reason this eyepiece does not have an adjustable eyecup like all other Pentax XLs. Instead, it comes with two interchangeable fixed eyecups -- one for eyeglass wearers and one for non-wearers. Works fine, but less elegant than the eyecups on the other Pentax XLs.

Overall Rating: 9
Weight: 6 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=42997

Pentax SMC-XL 40mm
Was so impressed with the shorter FL pentaxes, I traded the 35mm panoptic in for this. Sold it after one night out. Only the inner 50% of the field was usuable, there was so much astigmatism and coma, got rid of it and bought another panoptic.

Overall Rating: 6
Optics:6 Value:6
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=430969

Pentax SMC-XL 40mm
Some people (Idiots in my eyes) tested this eyepiece in Scopes, faster than f/6.4. Of course is the edge performance bad in "big" dobs
and fast chinese (junk) refractors.
First read the fucking manual then use the eyepiece (it said, the XL-line is calculated for f/6.4).
Other "experts" see astigmatism (of their own eyes), it has defenitly no
astigmatism.
First go to the "eyedoctor" then test eyepieces.
I tested this XL on C5, C8, Tak FS-102 and a awesome 16" Cassegrain (no SC) with over 4000mm fl and was very pleased by the
performance.
With the price, performance, coatings and the good looking in mind , I would give it a 11. (a 25 to screw up the average, wich is down
in account of the "experts")

Greetings from Germany
P:S: The Panoptics are the grandmasters of distortion - ROTFL

Overall Rating: 10
Optics:10 Value:10
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=244173

Pentax SMC-XL 40mm
I have a 14.5" Dobsonian. I bought this wide angle eyepiece because I could not bring my Tele Vue Nagler 31mm to focus in the telescope. The Pentax 40mm has very soft focus at the field of view's margin. By "soft focus" I mean that the edge of the field is blurry, out of focus. The margin is also quite wide, 20% of the image is affected. The contrast is weak, with poor definition throughout. By lowering my truss tubes 1/4" I was able to use the Nagler 31. What a difference! It was the poor performance of the Pentax 40mm that motivated me to modify the telescope to accomodate the Nagler. By comparison the Nagler shows crisp images that are clear to the edge and with high contrast and sharp definition. Looking at the Orion Nebula with the Pentax shows a gray cardboard-colored cloud. Truly nebulous. With the Nagler you see curdling and subtle variations in the structure of the nebula. I returned the Pentax to the retailer. It gets a 5 because it is half the price of the Nagler, half the weight, and it delivers half the performance.

Overall Rating: 5
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=43000

Pentax SMC-XL 40mm
I use this eyepiece with my F/4.5 10 inch dob. The wide field views are staggering! Despite the high exit pupil with my scope (near 9mm), I do not much notice the "wasted" 2 inches in effective aperture. As long as I keep my glasses on, the near edge performance is almost as good as the performance of my Panoptic 22. Without my glasses, my own mild astigmatism kicks in, increasing the distortion near the edge of field. The nearly 2.3 degree real field of view dwarfts the real field of my Panoptic 22 at 1.3 degrees. I did not notice any problem with blackouts either. The magnification, (using my F/4.5 10 inch dob) is sufficient for locating most deep sky objects easily. Small planetaries and faint galaxies can be a bit tough though. The Ring nebula is easily visible using the 40. Even M101 popped right out at me. This eyepiece is large (about the size of Nagler Type 4), but feels a bit lighter than the Nagler. The 10 rating is based upon the price to performance ratio. When compared to the cost of a Panoptic 35 or Nagler 31, it would seem to be a real bargain.

Overall Rating: 10
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=42992

Pentax SMC-XL 40mm
Excellent finder eyepece for fast dobs, light weight, great trasmission.
Lack of distortion a real plus for panning around. Amazing with a 2X barlow,
with only drawback being lack of range in eye position.

Overall Rating: 9
Weight: 5 (Veritable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=42989

Pentax SMC-XL 40mm
I loved my 35mm Pan until my buddy brought this eyepiece to our dark sky site. All I can say is Wow! No kidney beans or black outs and the edge performance was as good or maybe slightly better then the Pan. It is definately easier to view through as the eye placement isn't critical like the Panoptic. It is lighter then the Pan and cost much less. I sold my Pan and bought the 40mm Pentax and had money left over to go towards the 10.5mm Pentax. I think I might have to sell off all my TV's and buy the Pentax set. Highly Recommended!

Overall Rating: 10
Optics:10 Value:10
Weight: 4 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=67619

Pentax SMC-XL 40mm
I recently bought this eyepiece from Adorama(best prices around) and so far I love it. I am using it with a fast f/6.3 refractor. The ep is wonderful! It is big and bright and it is the easiest 40mm ep I have ever used. You can try to look for black outs or kidney beans but they are hard to find in this ep.
The edge is sharp up until about the last 5% or so but it is very slight. It is so easy to use, I don't wear glasses so I can just leave the eyecup all the way down and see the whole fov which is huge. This ep is a definate 10!

Overall Rating: 10
Optics:10 Value:10
Weight: 4 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=67508

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