Re: [APML] New Images

[Wei-Hao Wang <whwang@gmail.com>]

Thank you.

Jason, I mistakenly wrote Centuria Super again.  It should be Centuria 400
Professional.  It's still an old stuff.  I bought a dozen of them two years ago
and now I don't have too much left.  I need to buy the new one after I consume 
all my stock.  I don't have a hyper kit and didn't bring my dark room stuffs to 
the US with me.  This is why I never consider TP as an option.

Dave, the image quality of the 1.4x is OK, but not too excellent.  At the 
center of the field, the stars are as sharp as I hope.  At the corners, the
image quality is good, too.  However, there is a ring-shape region between
the corners and the center, where I can see significant aberration.  You can 
also see this on the larger image of M31.  I'm not sure if this will happen on 
your telescope.  My telescope is a flat-field refractor and its aberration is 
quite different from typical doublet APO.  Nevertheless, the field center is 
very sharp.  Are you going to use it on your Borgs?  Borg has its own rear-
converters.  They are designed for doublets.  

Cheers,

Wei-Hao

-- 
________________________________________________________________
Wei-Hao Wang  :)

Institute for Astronomy at University of Hawaii

Address:                       
2680 Woodlawn Drive         Personal Website:
Honolulu, HI 96822             http://www.ifa.hawaii.edu/~wang
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