Finderscope for Celestron 130EQ

killswitch (Edison) · #1 17-04-2013, 05:22 PM

Hey guys

I want to replace the hopeless red dot finder that came with my Celestron 130EQ. I am thinking between a Telrad or Orion 6x30 right angle. Price is roughly the same for both.

The scope doesnt come with a dovetail base at all so i need to drill the scope to add one, and attach a 6x30. I can safely drill without touching the mirrors.

Any thoughts on non magnified vs magnified finder for a scope like mine?

Cheers

RobinClayton · #2 19-04-2013, 11:10 AM

I started out with that scope - and while it was great for three years - I have to agree the finder was what really preventing me getting more from the scope.

Whatever solution you use will likely not be applicable if you change scopes - if you upgrade, then the new scope will probably have a better view finder anyway.

If you are expecting to do star hopping, then a view finder with some magnification is useful, because you will see more of the small stars that appear in the star charts, but are not visible with naked eye. The right angle on the view finder is useful for making it easier to use without bending your neck to odd positions. My suggestion is you get the finder with some magnification.

If you drill into the tube, be very careful to not touch the mirrors, but also don't allow the dust to get near the mirrors, they can cause scratching when you try to wipe them away.

mental4astro (Alexander) · #3 19-04-2013, 11:37 AM

Telrad is a funny beast: you either like it or you don't.

I sit in the "don't" camp. It is an effective finder, I acknowledge that, just not the right instrument for me.

I'm happier with a simple red dot finder. I can use both eyes very comfortably with it.

Most of my 'finding' is done with an rdf. But there are times that the optical aid that magnifying finder provides is preferable. These overcome the effects of light pollution, showing fainter stars than we can see naked eye.

My big dob has an rdf & 2 optical finders on it. The rdf is always the first port of call, the optical ones may or may not be called upon, but they are there when needed. My other scopes all have a dovetail mounting block onto which I can use either rdf or optical finder. Just depends on what I'm chasing & from where. The dovetail block allows for a quick & easy change.

A 30mm finder is good, but don't think that you'd be over doing it with a 50mm one. A right angle correct image 8X50 will be very effective on your 130 scope. I use one on my 114 scope too. Particularly from home, a 50mm finder offers much needed aperture grunt to find your way around. Andrews has them for $79 - more than the finders you mention, but it's got more guts.

Food for thought.

mental4astro (Alexander) · #4 19-04-2013, 12:00 PM

By the way, the rdf I mean is one like this that uses the same mounting block as the optical finders:

http://www.bintel.com.au/Accessories...oductview.aspx

killswitch (Edison) · #5 19-04-2013, 12:49 PM

Thank you for the responses.

I will go with a magnified finder and keep the stock rdf installed to quick find brighter objects.

I was thinking about the 8x50mm but i thought it might be too big and heavy for a smaller scope like mine. I might try out the Orion 6x30mm first. Ill be able to easily change it with the dovetail base installed.

Drilling should not be an issue, the holes will be a fair distance away from the secondary mirror. I will mask it to be safe and drill with the primary mirror side up.

mental4astro (Alexander) · #6 19-04-2013, 01:47 PM

Drilling shouldn't be an issue if you are confident with power tools. The main problem you'd encounter is having the bit move about as you start drilling. I used a sharp scribe to make a nice mark for each hole which helped a lot. Low speed too will give you most control.

Whether you keep the secondary in place or not, I suggest you place the OTA upside down on a table without the tube cover in place. This will see most of the shavings fall onto the table with minimal crap resting on the spider & top tube ring, and NO rubbish will fall on the primary.

The 8X50 finder is at least twice as heavy as the 6X30. If your mount's counter weight can be moved further down, you might be able to get away with the heavier finder.