red dot finders

[Scooter]

Hi Folks,

When the 12” newt is on the EQ6 Pro it is an absolute PITA to line things up between the OTA and finder etc. as well as just aligning on stars (doesn’t help my site isn’t the best – i.e sloping ground).

Now I have read that a Telrad is a fantastic piece of kit and should help me in this regard however I note that aside from the Telrad there are other red dot finders there for the same sort of price or a bit more. Now I was just going to get the Telrad however if the other pointers are better that could be a consideration thus I thought I would ask the question – just get the Tlrad or look at these other red dot finders – are they better or worse then the Telrad?

The Telrad seems to have a sleeker profile which I like however might make it harder to use then the others whichare further away from the tube.

Thanks in advance

[citivolus]

You can get a few different designs of RDF. Some of them have an enclosed reflector, some it is exposed, and some like the Telrad have it angled.

The gun sight RDFs from Taiwan can be had fairly cheaply, and they commonly have a selector wheel for different reticle types and brightnesses. Note that they are commonly too bright even on the lowest setting once it gets truly dark, as they were not designed for astro use. This type of RDF can be bought from GSO, WO, and Vixen if I recall, among others.

Baader, Televue, Celestron and others also have semi-enclosed designs, where the reflector is inside of a dew shield. These ones are designed more for astronomy use, and while I have not used one I will likely switch to one from the above type at some point.

Make sure that whatever you get, it is stable and easily adjustable, and goes as dim as you need.

Regards,
Eric

[Geoff45]

I have both, an RDF on my refractor and a telrad on the reflector. Performance-wise they are much the same. The big advantage of the RDF is its stability. I take it on and off the scope and have only adjusted it once in 3 years. However, that's also since the main scope is a refractor. With a reflector you'd have to adjust every time you recollimate and the RDF's usually need an allen key to do this. So, IMO
*RDF with a refractor
*Telrad with a reflector.
Geoff

[Astrobserver99]

I have a Rigel Quickfinder with has adjustable brightness and centering. It's a breeze to use on all of my scopes. I would'nt use any other red dot finder.

[astroron]

I don't have a great deal of respect for most of the RDF's I have looked through:( usually too bright, fog up to easily and you have to look to far back to get an idea where you are looking at:(
I have two Telrad's and would not have any other Zero magnification finder:thumbsup:

[bojan]

If too bright, you only have to replace original resistors with higher values (which I have done) .
After that, it is a treat :thumbsup:

[Scooter]

Thanks for all the replies folks :thumbsup:

Astro99 your mention of a rigel quickfinder let me do some google searches that gave me a heap of compares ( e.g http://www.cloudynights.com/documents/finders.pdf ) and at this stage looks like I will go the Telrad (mostly because of the comments on motion induced parallax).

[astro744]

The Telrad has 4deg, 2deg & 0.5 deg circles which can nicely match your finder, low power eyepiece and mid power eyepiece in most 'scopes.

If you want it further from the tube just mount the base on an aluminium bracket. Extra bases can be added to other 'scopes although multiple Telrads are more convenient to avoid centreing the circles when changing 'scopes although not essential.

Batteries last for ever and the unit has variable brightness. Many astronomical resources refer to Telrad fields for locating objects and for star hopping.

Based on WWII bomb sights the Telrad was the pioneer in astronomical 1x finders in the 1980's. See also http://www.company7.com/telrad/products/telrad.html

Here are some examples of finder charts:

http://www.custerobservatory.org/docs/messier1.pdf

http://www.utahskies.org/deepsky/caldwell/charts/caldwellTelrad.htm

http://www.atmob.org/library/member/skymaps_jsmall.html

[hulloleeds]

Makes you wonder why we get these magnified finders with a lot of scopes. About the same price as a telrad but significantly more difficult to use.

[JethroB76]

Magnified finders are still important and serve a role.
I have both a rigel and a RACI 9x50 finder on my scope.