Quote:
Originally Posted by glend
Well given all the issues raised and discussed re the12" yes I believe the 10" f/4 is more mainstream and easier to setup - thus the 'safe' bet.
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Hi Glend,
This thread is now finished.
The 12" f/3 was too much of a gamble.
I have ordered the cheaper Carbon fiber 10" f/4 Newt. with the electric focuser option.
see here:
http://www.teleskop-express.de/shop/...rbon-tube.html
I believe it only has GSO mirrors but they are checked.
I intend to upgrade the mirror to a 10" f/4 sandwich or honeycomb mirror from Hubble optics
but that will take up to 6 months delivery.
That way I get a carbon fiber Newt. with low weight & low coefficient of expansion
& up to 10 x faster cool down to ensure the boundary layer of air is at the same temp as the mirror.
The 10" f/4 is 3 Kg lighter than my 8" f/6 Newt so very nice on my modded EQ6 mount.
If I find there is too much vignetting of the flats then I may change to a 3" focuser & the ASA coma corrector:
http://www.teleskop-express.de/shop/...orr--Feld.html
This will be a nice upgrade from an 8" f/6 Newt.
I have calculated - considering the size of the secondary mirrors that I will
have system where the 10" f/4 will collect 3.35 times the light per unit area in the same time.
That means 3 minute sub frames now in 54 seconds with only a slightly shorter focal length : 1200mm to 1016mm.
cheers
Allan & thanks to everyone for all your help.