need for a separate finder scope

[SimmoW (SIMON)]

Hi, I'm waiting for delivery of my new 130mm reflector, to be used primarily for astrophotography. I know I'll be getting an Orion mini auto guider and scope kit.

So I'm wondering, will I also need a separate finder scope? I'm guessing not , but am interested in what you all think/use. I'd rather keep it simple if possible!

As my scope only has a focal length of 435mm, this might make positioning via the autoguider practical?

Thanks

Simon

[niko]

I use an ED80 and a guidescope but also have a finder because loacting things visually when aligning etc is easier than chasing things in the guidescope window which can be endlessly frustrating

[Poita (Peter)]

I much prefer a Telrad for that kind of scope. Makes positioning much easier than using a finderscope.

[julianh72 (Julian)]

Originally Posted by Poita

I much prefer a Telrad for that kind of scope. Makes positioning much easier than using a finderscope.

+1 for the Telrad / Red Dot finders! It makes visual alignment of the scope so simple - and you can pick up a simple red dot finder for around $30 or so.

[SimmoW (SIMON)]

Ooh, that sounds interesting. Just how do the red dot finders work? Sorry for my basic questions!

[julianh72 (Julian)]

Originally Posted by SimmoW

Ooh, that sounds interesting. Just how do the red dot finders work? Sorry for my basic questions!

Simply put, a Telrad / Red Dot Finder has a curved half-silvered zero-magnification glass which displays the reflection of a glowing red dot or other target (e.g. concentric circles in the case of a Telrad) which are projected to infinity.

What does that mean? You see a red illuminated target (dot, circles, grid, or whatever) which appears to just hover in the sky with no magnification, and virtually no parallax. Just align your telescope until the red dot is over your sky target, without needing to bring your eye up to an eyepiece, and you are basically on-target.

I use a second (conventional magnifying) finder-scope for precision targeting if necessary (e.g when your target is not visible to the naked eye), but most of the time the red dot finder is adequate to bring the target object into view with a wide-angle eyepiece.

I suspect that once you have tried one, you will always want one - luckily, they can be had very cheap!

Here's a bit more information on how it works:

http://en.wikipedia.org/wiki/Reflector_sight

[Camelopardalis (Dunk)]

I use a Rigel Quikfinder on my smaller scopes as it's a kit smaller and lighter where tube room is tight. Does essentially the same thing as the Telras but with only 2" rings of 0.5 and 2 degrees diameter. The Telrad has a third ring at 4 degrees and is great if you have the tube space