Quote:
Originally Posted by Suzy
The stars aren't as pin point as my XW or LVW- could it be the astigmatism it's picking up from my eyes that my other eyepieces don't?- I don't know.
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Hi Suzy,
I don't think this is likely to be the case.
Generally your own eyes astigmatism, if not corrected with glasses or a dioptrix, will get worse as the exit pupil gets larger. This means assuming the same telescope, the longer the eyepiece focal length the more noticeable your own eyes astigmatism becomes. On that basis assuming you are using both eyepieces in the same scope, your 22mm Vixen LVW would show more astigmatism and star flaring than the 14mm Denkmeier. I don't believe this is what you are seeing?
Things then become a mystery. I have used 3 different samples of the 14mm Denkmeier in newtonians as fast as F4.5, and found them all to give a really sharp flat field view across the entire FOV, without a paracorr. In fact when I directly compared the 14mm Denkmeier to my 14mm Pentax XW in my 10"/F5, I found it to be noticeably better in the outer 60% of the FOV than the 14mm Pentax XW, due to the slight field curvature of the 14mm Pentax XW, when it is used in a newtonian without a paracorr. I am really puzzled here as to why you are seeing what you are seeing and I am wondering if you do not have an eyepiece which has some slight quality control issues. eg. slight misalignment of a lens for example during assembly. If you can find someone else with a 14mm Denkmeier to compare against, or maybe even someone who will loan you one to make a direct comparison with your own eyepiece. The only 3 I know of and have used are all now located outside Australia. One of which belongs to Scott Mitchell (Wavelandscott), who moved back to the USA.
Cheers,
John B