how to view constellations in finderscope?

Question

I switched my skyquest XT6 for an XT8 since it's better for DSO's. I'm great at locating planets because they're bright, but the problem is when I use a book reference (e.g. Turn Left at Orion) to locate galaxies, etc. I have a 9X50mm correct-image right angle finderscope. When I look through it, I don't know where I am on the constellation I'm looking at relative to the other stars in the constellation. Does anyone understand what I'm trying to say? If the whole constellation was in my finderscope, I would know what I'm looking at, but only one or two stars of the constellation are in the finderscope (..I think). Moreover, I also see other stars among the constellation that don't belong to that particular constellation that I'm looking at, so the image looks NOTHING like what I see when I look up in the sky (which are the stars that are the most prominent in brightness). Should I get binoculars ? Is there a good BEGINNER book of the constellations?

Answer 1

I know exactly what you're talking about. The problem with right-angle finder scopes is that you have no point of reference because you're looking in a different direction than the finder is pointing. Supplying right-angle finders as standard equipment on telescopes, as Orion is currently doing, is, I believe, a serious mistake. I've always used a "straight through finder" because I could look through it with both eyes open, one looking directly at the sky and the other through the finder. This makes it quite easy to point the finder, especially if you practice a bit with binoculars. So, yes, I'd definitely recommend binoculars...10x50s are excellent.

What you also need is a second finder to get the main finder pointing in the right direction. There are two good kinds: Telrad and Rigel QuikFinder. These are called 1 power or head's-up finders. They project a red target on the sky which you view from behind them. Move the target to the right place in the constellation with both eyes open, and then switch to the optical finder to fine tune locating the object. Many people find a Telrad or QuikFinder all they need and get rid of the optical finder completely.

Books: Turn Left At Orion is excellent. NightWatch by Terence Dickinson (Firefly Press) is another great book. I also recommend joining an astronomy club and getting some hands-on help from an experienced astronomer.

Answer 2

I guess the problem is that the finder is going to give you about a 5 degree field (give or take) and most constellations are several times bigger than that. (I can just about squeeze all of Crux into the view of my 10 x 50 binoculars, but then it is the smallest constellation.) You need a bit of practice navigating around constellations using the finder. A pair of binoculars (7 x 50 or 10 x 50, that'll match your finder reasonably well) is probably a good idea to help you through this process.

A planetarium program like Cartes du Ciel (I use it, it's free) can help too by allowing you to make maps at different field sizes and to an appropriate depth (i.e magnitude).

Answer 3

Constellations are too spread out to be visible in a finder scope. Even the widest field binoculars won't get constellations in the field of view. Only your unaided eyes will encompass constellations.

Back when I used to look for Messier objects, I used to set the telescope on a star which has similar declination to the object I want to see, then you can work out when the object will come into field of view by simple arithmetic based on the right ascention of the star and the object

eg star 2hr 14, object 2hr 39. The object will come into view 25 minutes after you set the finder on the star.

You can go away and make a cup of tea.

Answer 4

You can see lots of craters on the Moon, the rings of Saturn, the moons and major atmospheric belts of Jupiter, the phases of Venus (and Mercury if you can find it), the polar caps of Mars (when it is near opposition), the featureless but small greenish disk of Uranus, and Neptune looking pretty much like a star. You can easily see the Orion nebula, as well as a number of other bright nebulae and star clusters. You can see some galaxies, but be warned they are very dim and do not look like the photographs of them which are taken with long exposure times to make them look much brighter than they really are. In many cases you will not want maximum magnification, except probably on the planets. You change magnification by changing eyepieces and you can triple the magnification of any eyepiece by putting the barlow in the eyepiece holder and then putting the eyepiece in the barlow. As a beginner the hardest thing will be finding the objects and getting the telescope pointed exactly enough to see them. The source is a star chart that will tell you what is up at the moment.

Answer 5

Well I gave my Telescope to a child, but, I just had a simple Star Locate Wheel. It not cost much and you turn it to the time for your area to locate those Stars, Constellations, Planets etc. I not remember what it was called, I try to find, but, not search much. Cost about $5. also, there are programs for the computer and free. I not say they great but I use Stellarium, maybe it help you.
http://www.stellarium.org/

This what it look like; http://www.starmagic.com/catalog/3700129P.JPG
Here one for sale; http://www.starmagic.com/1D3C010.html
But, usually they cheaper and NO Shipping cost if you find local.
Good Luck and have fun. I have a friend and he really into this, I just go to his house now. He have a really good Telescope, filters and all for looking at the sun, Awesome.

Answer 6

I completely agree with Geoff G - get something like a Telrad. An alternative is to get a paintball gun sight and fix it to your finder. You'll need to fiddle about a bit to get it collimated, but it's a cheap alternative. Another thing you can do is spend some time looking at the area with binoculars - I find it easier to orient myself that way.