Thread: 8" Newt for AP
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Old 03-08-2017, 11:52 AM
cadman342001 (Andy)
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Join Date: Mar 2017
Location: Queenstown, New Zealand
Posts: 95
8" Newt for AP

Ok so my plan for doing AP is, cos I'm basically unemployed/retired, is that rather than spend over a grand for an 80mm refractor I'm going to get an 8" Newt which will be about half that.

It's my 50th in December so I'm getting this sorted now so that I can my wife and the kids the lowdown on the exact present that I want !

Considerations - Refractor vs Relector

Cool down / warm up times - I live in Cairns, the temperature inside and outside the house are always the same. We have/use no heating or AC.

Collimation - never done it but don't think it's that hard and will get a Cheshire laser thingy ?

Diffraction spikes ? I like 'em personally !

I have a HEQ5 Pro so am limited to 13.7kg payload which rules out the 10" I think as I can't afford the CF version.

What else ?

Better to go with a 1000mm/200=f5 or 800/200=f4 ? I guess it's a trade off between more coma with the f4 (which can be corrected with a corrector right?) but shorter FL so "easier"/longer subs, or the f5 less coma but the longer FL makes harder?

These are the options (all proper Newts optimised for AP) :

https://www.bintel.com.au/product/bi...4-imaging-ota/

http://www.astropetes.com.au/telesco...wtAstro_8.html

http://www.myastroshop.com.au/produc...p?id=MAS-069A4

Bintel seems to give lots of info on theirs and why it's better, and they have a good reputation (eg check and collimate their scopes before they send them out) but is the Black Diamond better ? Might be able to stretch to the price of that if it is. I've seen that one at $999 elsewhere.

What do you think ?

Andy
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