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Pentax XL 60mm

1. Technical Specifications

- Focal lenght 60 mm
- FOV 65°
- Fieldstop diameter 72 mm
- Diameter lens eyeside 65 mm
- 5 elements in 4 groups, fully SMC multicoated
- Eyerelief from 10 mm to 44.4 mm
- Weight 1.650 gramm
- Instead of barrel it comes with M84x1 thread
- Inside the bottom side it have a M77x0.75 filterthread
- lenght 253 mm
- Upper diameter 84 mm
- Partial rubberamored housing

2. Description

The eyepiece is made from CNC maschined black anadized aluminium body. The lenses are fixed in the upper 1/3 part of the housing surrounded by the movable eyeguard, with which you can search your best eyerelief, changable from 10 mm to 20 mm. The 44.4 mm is the distance from eyelens to focus. With this movable eyeguard you have the possibílity to find the most comfortable eyerelief for yourself. Works similar to the movable eyeguard on the XL 40 mm.

The upper part has an outer rubber ring to hold the eyepiece safety in your hand. On the lower part just above the connection thread is another rubber ring. I expect that this eyepiece is made that long to be used straight through in the larger 8" and 10" Pentax Apos. For myself I would cut the eyepiecetube for at least 100 mm less lenght and would attach an adapter for a 3" Stardiagonal. With the original contruction it requires lots of backfocus on your scope.

3. Impressions

I used this eyepiece straight on my Zeiss Semi-Apochromat AS 130/1950 on which is provides a 32,5 power and an exit pupil diameter of 4 mm, just the right size. The field of view I am getting with this eyepiece on this telescope is about 2.1 degree. I used the eyepiece now on diffrent daytime objects, in nighttime I watched a birght traffic light and between the clouds some stars.

At daytime it provides razor sharp images up to the fieldstop without any kind of lateral color. I did not notice that little yellow touch of false color I see always in the shorter XL eyepieces. Watching at night the bright traffic light and moving it through the field i could not see any ghostimages, thanks to the famous Pentax SMC coatings, I expect. Looking between the clouds to the sky, they daytime observing was repeatable, stars in my scope are pinpoint to the fieldstop. Kidnebean effects have been totaly absense on daytime as well as on nighttime.

4. Price

It is the most expensive eyepiece I ever heard about, US $ 3,900 plus shipping. If the eyepiece would run in the range up to US $ 1,500 I am pretty shure i would buy it, but $ 3,900 , outch; this is even for me a little too much.


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