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Alternatives to right angle finder

Started by rrasmussen, 09/06/2010 06:18AM
Posted 09/06/2010 06:18AM Opening Post
Hello again,

Been enjoying my new Orion 10" dob, but am discovering the right angle finder scope isn't the most useful tool for locating objects quickly, even bright reference stars. First I have to eyeball the scope to line it up with the target star and then hope I'm close enough so that when I adjust the altitude, I'll find it. It's easier on bright reddish or orange stars like Antares or Arcturus, but isn't so easy when trying to locate one like Mizar. I'm trying to decide what might be the best alternative, either to replace the finder scope, or complement it. I live in the SW Chicago suburbs, so light pollution is a factor unless I drive an hour or more away.

Telrads seem quite popular and highly recommended to say the least. How do other devices like Rigel Quickfinder or Orion EZ Finder stack up?
What about a green laser mounted in place of my finder scope?

My particular scope is Orion's 10" Intelliscope. Yes I know I got the computer, but still you gotta find the reference stars and even so, I'd like something where I can easily visualize where the telescope is pointed.

Roger


Posted 09/06/2010 07:38AM | Edited 09/06/2010 07:41AM #1
Ad a unit power finder. for basic straight down the scope pointing, to work with the right angle powered finder.
Start with an affordable red dot finder, that is light and small.
There are lots of options, they all work.
Telrads are very cool, but powered finders can be more helpful under light pollution.
Laser pointer finders are very cool, but can have battery power issues in colder weather, which is coming.
You could even make a simple peep sight or open pin sight for your scope. No battery required at all.
Posted 09/06/2010 08:18AM #2
Hi;

For a newtonian, my favorite combination is a telrsd and a straight-through magnifying finder. If there is light pollution, then just a straight through finder is enough.

The advantage of the straight through is that you are looking in the direction the scope is pointing. You can even start with both eyes open and you use it much like a red dot finder.

The downside is that it takes a while to become accustomed to the reversed image. It can complicate using star charts.

If you are starhopping in Chicago then a magnifying finder is a must, if you are using the intelliscope, then you can probably get by with just replacing the right angle finder with a red dot that uses the same. Amounting dovetail. Most do.

Jon.
Posted 09/06/2010 08:30AM #3
You have gotten good advice already.

Just to amplify...

Green lasers are not a good idea. Why add light to the sky?

I use Quickfinders and Telrads. I prefer Quickfinders because they are compact, and flash on and off. I prefer Tel-rads because they are slightly easier to see, correct better for parallax, and are more stable (don't move around with a little bump). In use, there is not much difference.

In light pollution, where you cannot see dim stars, reflex finders (red dot, Quickfinders, Telrads, etc) are not as useful for detailed star hopping as a magnifying finder scope since you cannot see the stars you need to star hop.

Alex
Posted 09/06/2010 02:07PM #4
Make sure your RA finder is in focus and aligned with the scope. If its slightly out of focus stars will be dim.

Is the finder a RACI (right angle correct image)???
These finders work well with star charts. Just match the chart with the finder view. Add a Telrad and you're set.
RA finders with mirror image are near impossible to use with dobs.

Dont attach the Telrad or Rigel permanently at first. Experiment with placement. The double sided tape is immovable.

Practice aiming your scope using the RA finder. Lyra works great as the stars are all bright and close together. Ive been satisfied with Antares 8x50 RACI finder.

John