Pentax XL's in binos?Posted By Victor Kennedy |
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.
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.