Bolton Astronomical Society

new telescope
Page 2 of 2

Author:  DRatledge [ Tue Feb 11, 2014 12:46 pm ]
Post subject:  Re: new telescope

The Ascension seems to have FCD1 glass which is not FPL53. I guess it emanates from the United Optics factory in China (or one very similar). However, I wouldn't get hung up on glass types. I recommend you reading the Altair Astro's blog on glass types which covers more than just the glass.
A Strehl ratio 0.9 for a an apo refractor is nothing special (ie 90% perfect) and unless the telescope comes with its own test report I would take it with a pinch of salt. Sounds impressive though quoting a Strehl ratio.
Have a look at the Starwave 80mm next meeting - hopefully either the Society's or Ross's should be there. These doublets perform well as does the bigger 102mm (Gerald) and the 110mm (Carl). Gerald's 102mm is magical at holding focus with changing temperature. My Takahashi with 2 fluorite lenses cannot hold focus for an hour. Andy's William Optics 72mm is another great performer - won't break the bank and is very light weight.
It's complicated isn't it but the advantage of being in a society like ours is you can learn from others experience rather than by trial and error. Have a look at the gallery images the guys have taken - that's proof as to what works in Lancashire.

Author:  ANuttall [ Tue Feb 11, 2014 6:25 pm ]
Post subject:  Re: new telescope

I have read the blog on the altair astros, and lots about the acension which most people seem to say it's a Meade 5000 series scope, maybe I'll wait as you say until after the meeting and have a look at other peoples setups.
The amount of reading i have done over the last few days is enough to make me weep I 'm now totallyconfused. com from Shaw,

Page 2 of 2 All times are UTC
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group