Excelsis - Display Vote

Pentax SMC-XW 14mm

I would like to give the Pentax a high rating, but in my 6" Apos there was considerable curvature of field. Had I not looked at the moon my rating might have been higher, but when I focused at the center of the field of view the edges were out of focus, and when I focused at the edge the center was not sharp. A very frustrating experience for such an expensive eyepiece. I had seen Saturn through the 82" at McDonald observatory through a friend's previous generation Pentax - it was spectacular - and I was expecting an even better eyepiece in the new generation. Using it for terrestial viewing during the day I never noticed this effect.

Overall Rating: 5
Optics:6 Value:5
Weight: 1 (Unreliable Vote)
Date: 02/19/2005 11:59:22 am PST
By: Anonymous (xxx.xxx.4.16)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=420675

&gt;I would like to give the Pentax a high rating, but in my 6&amp;quot; Apos there was considerable curvature of field.  Had I not looked at the moon my rating might have been higher, but when I focused at the center of the field of view the edges were out of focus, and when I focused at the edge the center was not sharp. A very frustrating experience for such an expensive eyepiece.  I had seen Saturn through the 82&amp;quot; at McDonald observatory through a friend's previous generation Pentax - it was spectacular - and I was expecting an even better eyepiece in the new generation.  Using it for terrestial viewing during the day I never noticed this effect.
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I also tested this EP out on my 12&quot; f/5 reflector and the field curvature was very prominent 80% of the way out. Still, the contrast is amazing and I saw a wealth of detail on Mars this morning when it was 17&quot; large. Galaxies also have better contrast if you dont mind field curvature when looking in this particular EP.
I would rate it a 10/10 for contrast and 7/10 for flatness from edge to edge.

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