FreeLists / az-observing / [AZ-Observing] Re: The Orion 120mm ED Refractor

[DBogan3220@xxxxxxx]

Then why bother with a refractor. Celestron had the C5 Schmidt Cass they  
marketed for years and produced decent color free images. The Orion Achro  
Doublet is OK but being an Achro suffers from Chromatic Aberration with the  
corresponding loss in contrast due to CA and Sphero Chromatism. Again the fix 
is  
simple a Newtonian has all the advantages and the cost in the most minimal. 
Both  
the Orion Achro and APO are relatively long for their size. If what you are  
looking for is a quick setup scope for the moon or planets then to me it would 
 be the Newtonian. The big plus for the short focal length APO is the 
portability  and the high contrast available when you want to take the 
instrument to 
high  powers. Of course if your interested in wide field Astro-Photography 
with 35mm  or the 6X7 film format or CCD then the APO is the way to fly. Last I 
might  mention that a lot of people don't see the Chromatic aberration in the 
doublets.  Its come to mind that a lot of Americans out there are color blind. 
So a short  focus Achromat is going to appear quite good. I have perfect color 
 Vision and I find the color in the Achromat to really objectionable esp at  
the higher powers.  I've come to this conclusion because of all the  reports 
I've read about how people just don't see the color error in the  Achromat at 
all. Even when you explain it to them they still claim they just  don't see it.
 
Clear Skies
Dwight L Bogan
 
 
 
 
In a message dated 8/5/2006 6:13:39 P.M. Pacific Standard Time,  
stan_gorodenski@xxxxxxxxxxxxx writes:
remember  Orion had a 5" refractor that they called an ED(I think) 
5-10(?) years  ago. It was in a white tube and was fairly inexpensive. I 
looked through  one at RTMC and it seemed good to me, but I am probably 
not hard to  satisfy in this regard due to my ignorance of really super 
refractors. For  some reason they stopped producing it.

Last year when I was in NM I  stayed overnight at the Oliver Lee Memorial 
state park south of  Alamogordo. I got in late at night, and as luck 
would have it a person,  Fred Sweeney, needed to have his vehicle jumped 
so he could charge the car  battery in case he needed to take his wife to 
the hospital. He had an  Orion 5" refractor set up. It had a white tube 
but was not the ED.  Although not an ED I was impressed at the quality of 
the images, if you do  not demand too much. When necessary, he used a 
lens from Orion that is  supposed to reduce the chromatic abberation. If 
one is not too demanding,  the Orion is probably a real bargain for the  
price.
Stan






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