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Pentax XL's in binos?

Started by tomdisco, 02/17/2004 08:33AM
Posted 02/17/2004 08:33AM Opening Post
I am not yet into binoviewing and XL's are my favorite EP's. Comments by Chris Nicholl & Doug Culbertson on another thread have me concerned, particularly regarding whether or not pairs of these will "fit my face". I guess what I am looking for is comments from other XL/bino users. How prevalent a problem is this? Are there a number of you who do not experience this problem?

I had planned to build up maybe three pairs of XL's before actually buying a Denk bino but now I am wondering if I need to find someone with binos to test this out before I start collecting any more EP's. I already have two 10.5 XL's.
Posted 02/17/2004 08:43AM #1
James,

Since you have more than one, you can hold them up to your eyes and see if they work. If you hold them up and they touch before matching up with your eyes, your interpupillary distance (IPD) is too narrow. I can't use the XL's because my IPD is 58mm and the XL's centers are 60mm's apart at their closest.

Another issue to consider is nose relief. If your IPD is compatible, hold the XL's up to your eyes and look through them. See if there is enough room to fit your nose in between the ep's. Hold the ep's straight out from your eyes and then tilt them up just slightly as if you were looking up just a tad into the ep's.

Let us know what you find.

Clear skies,

Tom
Posted 02/18/2004 02:21AM #2
I have a pair of 28 mm Pentax XLs that I use with a BW Optik binoviewer. They are big eyepieces, but my eyes are wide enough apart that I can use them, and the image merges well. Nose relief is important with these eps because of the size of the rotating collars. My nose won't fit between the eyepieces so I can't get both eyes right down to the eyepieces as I can with my 2 25 mm Tak orthos.

However, the appeal of the 28 mms is that they are sharp right across the field of view in both my C8 and f/6 refractor. I used to have a pair of 19 mm Axioms that worked well in the C8 but showed some edge distortion in the refractor. They had a 70 degree afov, compared to the Pentax 55 degrees, but I still prefer the Pentaxes. As others have noted, the field of view seems wider in a binoviewer. I also used to have Meade 13.8 and 18 mm Superwides; I never tried them in a binoviewer, but they had even more edge distortion (to me) than the Axiom. They would probably be ok in a longer focal length scope.