View Single Post
Old 06-09-2007, 09:41 AM
erick's Avatar
erick (Eric)

erick is offline
Join Date: Dec 2006
Location: Shoalhaven Heads
Posts: 8,481
Originally Posted by thongus View Post
Hi to you, thongus.

Originally Posted by thongus View Post
Should only an experienced star gazer who could star hop use a dobsonian?
I expect that you mean a dobsonian reflector without any digital setting circles, nor driven axes? If so, yes, you fundamentally have to know how to work your way from one star to the next, otherwise you will just be observing randomly, or have to sweep through the target area hoping to spot what you are looking for. But knowing how to use the finderscope and/or a laser pointer attached to the scope will greatly assist.

Originally Posted by thongus View Post
Also, with eyepieces whats the best size for an 8' reflector?
An 8 foot reflector! Wow. I'm sure you mean 8 inch, that's what I have. I have eyepieces from 40mm to 6mm which is magnifications of 30x to 200x. When I introduce my 2x barlow, those magnifications double. I think you'll find this is the maximum useful range. I wouldn't go below 40mm, but you may wish to try a 5mm or 4mm eyepiece if you can borrow one.

Originally Posted by thongus View Post
and why are some 100 where'as other eyepieces are $500!!!! is there a huge difference in what you could see?
Apparently so, since I doubt anyone pays $400-500 more for an eyepiece just for the "name"! I can tell you that a $175 Vixen LV 6mm is heaps better than a $39 GSO 6mm plossl. Same for an Orion Stratus and a Pentax XF I had a chance to borrow (around $200 eyepieces). I'm not sure whether one would invest in $400+ eyepieces if all one had or planned to have was a mass produced 8" reflector. But if you are sure you will upgrade to a bigger and better scope some day, maybe it is a good move. Depends on how fussy you are with your view and how many discretionary $s you have. Read the many many eyepiece threads on the forum.

Originally Posted by thongus View Post
I have a star map, can cannot find any stars in the sky!.. what am i doing wrong?
Wait for the clouds to go away? Sorry, I couldn't resist! Do you have a Planisphere as well? Maps are very useful, but you also need a picture of what the sky overhead looks like, at the time you are looking! Put the telescope away, and the binoculars. Sit back with your Planisphere and redlight torch and work with the sky until you know and recognise several major stars. Then update to the binoculars and see if the view around those stars can be compared to your star map. Then get the telescope out and get it pointed at a bright star (with the longest focal length eyepiece you have, therefore lowest magnification) and compare that to what you are seeing through your binoculars. Yes, it's all upside down and you'll need to train your brain to that fact. Watch out for the Planets - Venus, Mars, Jupiter and Saturn don't appear on your Planisphere or star maps, but can be very bright, so can confuse you. (Duh! I did it early this morning - was looking at Aldebaran in Taurus, so I thought. No, that was Mars - fooled again )

Suggestion, start with the Moon - it's easy to get that in your field of view and there is plenty to see and you'll get used to moving your scope in the right directions to track the moving object and to see different parts of the object.

Hope some of this helps?

Reply With Quote