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Upgraded finder for an 8SE?

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#1 mostlyemptyspace

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Posted 02 May 2014 - 01:23 PM

Hi all. I have an 8SE and the little red dot finder is *BLEEP* out on me. What do you guys recommend as a replacement? I had a Telrad on my old dob, but it seems a little too clunky for this scope. I'd like to spend less than $50 on whatever it is.

#2 Midnight Dan

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Posted 02 May 2014 - 02:25 PM

There's not a lot out there for under $50. Even a replacement RDF like the one you had will run you $30-$40 depending on where you buy it. I use a GLP (green laser pointer) and 9x50 RACI combination and love it. But those two, along with mounting hardware, will set you back around $150.

If I had to recommend just one finder that is close to your price range and will work well on the 8SE, I'd suggest the Orion 6x30 RACI for $59:
http://tinyurl.com/762zofq
The 6x30 gives you a wider field than the 9x50 so it's easier to acquire your target initially, but still provides a bit of magnification and more light grasp than a non-magnifying finder. Plus, the right-angle diagonal makes it a lot more comfortable to use.

Unfortunately, on top of the cost of the finder, you'll need to replace Celestron's proprietary finder shoe with a more standard Synta/Orion style shoe which will cost you another $25. However, if you do that, you'll then be able to use most standard finders in the future.

-Dan

#3 hamdul

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Posted 02 May 2014 - 02:34 PM

Dan,
Oooops! Dan I think that the shoe from Orion goes for $17.00 and some change, at least that's what I remember when I bought mine. :p

Fred

#4 Midnight Dan

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Posted 02 May 2014 - 02:40 PM

Hi Fred:

You are correct! I was looking at the prices at ScopeStuff which includes 'free' shipping. Not sure what the Orion price is with shipping, but the purchase price is $17.99.

-Dan

#5 hamdul

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Posted 02 May 2014 - 06:16 PM

MostlyEmptySpace
I just checked Agena Astro and it looks like they have a mounting bracket for $13.95 with free shipping. :jump:
Fred

#6 mostlyemptyspace

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Posted 02 May 2014 - 07:55 PM

Is this the mounting bracket that will fit the 8SE?

Also, this 6x30 RACI doesn't use batteries, right? Is it as easy to align with this thing as with a Telrad?

#7 hamdul

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Posted 02 May 2014 - 09:36 PM

Yes that looks like it BUT Agena Astro has free shipping and their service is great.

Fred

#8 Midnight Dan

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Posted 02 May 2014 - 10:53 PM

Hi mostly,

The one in your link says explicitly in its description that it is NOT intended for use with schmidt-cassegrain telescopes ... although I'm not sure why.

I would go with the one Fred mentioned from Agena:
http://agenaastro.co...er-bracket.html

The 6x30 finder does not need power because it is not illuminated. It should be as easy to align as a telrad, and probably more accurate because of the magnification factor.

-Dan

#9 mostlyemptyspace

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Posted 06 May 2014 - 12:54 AM

I still can't decide between a Telrad and this 6x30 RACI finder.
Anyone tried both on an 8se?

#10 Midnight Dan

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Posted 06 May 2014 - 06:18 AM

Yes, I had both on the scope at the same time and decided to get rid of the Telrad for a number of reasons. First, it puts your head in an awkward position for viewing through it, just like the red dot finder. Second, in my opinion it just looks clunky and out of place on an elegant scope like the SE. Third, it dews up faster than the corrector on an SCT.

And finally, I don't think it offers any advantage on a goto scope. It's designed primarily for star hopping and is excellent at that job. But with the 8SE, you never need to star hop. You only need the finder for the alignment process. A small, comfortable to use, RACI does the job fine. And since the RACI provides some magnification, it also makes the star appear brighter, easier to see, and more accurate to align on.

-Dan

#11 Bob Griffiths

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Posted 06 May 2014 - 07:32 AM

Heck at one point I had a Telrad, a laser plus a RACI finder on my scope all at the same time for about 3-4 months...

I removed the telrad because I make so little use it...BUT I could also have removed the RACI finder for the same reason...The reason I left it on the scope is that while I do not use it as a finder I do it it as a small wide field Telescope in its own right

For alignment I use my Laser ..

BTW... I love the look of a Telrad (pure function..industrial design..

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#12 mostlyemptyspace

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Posted 06 May 2014 - 11:59 AM

Man that thing is crazy! Aren't you worried about all the weight?

Sounds like the small RACI is the way to go. Thanks for the input guys.

#13 Bob Griffiths

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Posted 07 May 2014 - 02:50 PM

Man that thing is crazy! Aren't you worried about all the weight?

Sounds like the small RACI is the way to go. Thanks for the input guys.


Been using that scope for 8 or 9 years now the way it is set up... IT has never let me down...accurate GoTos & Tracking (has kept the ENTIRE full moon within the fOV of a regular 25 mm eyepiece for HOURS...

I have about 7 pounds on top (from memory because we have had this discussion before

Bob G

#14 oliverschurer

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Posted 09 May 2014 - 09:00 AM

I also use all three finders on my 8se - a Telrad, a 9x50 RACI, and a GLP. I use the Telrad during alignment 60% of the time, and the RACI 30% of the time. The GLP is mainly just for fun. No issues whatsoever with the added weight or balance.

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#15 mostlyemptyspace

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Posted 09 May 2014 - 11:38 PM

Holy *BLEEP* what is that platform your hand control is sitting on. I need that. Stupid thing is always falling off and bouncing around everywhere.

#16 Midnight Dan

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Posted 10 May 2014 - 08:53 AM

Hi mostly:

Not sure about that one that Oliver uses, but here's the one I have:

http://www.jmitelesc...ng_brackets.htm

-Dan

#17 oliverschurer

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Posted 10 May 2014 - 09:09 AM

Mine is the 'Wing Thing' from S&S Optika in Colorado. It works fine but is not a great fit in the handset cradle. I would probably buy the JMI if I had it to do over again. Nice to have.

#18 Peter9

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Posted 10 May 2014 - 11:11 AM

Hi M.E.S,

I made my own from sheet alumimum. It is attached to the rotating part of the mount using velcro. I also find the hand set more comfortable to use from the position I have it, as apposed to the position of the "wing thing". ( I tried mine on a bracket mounted there)
The stripped tape is an aid to locating it in the dark.

Regards. Peter.

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#19 Peter9

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Posted 10 May 2014 - 11:12 AM

And with the Hand Set in place.

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#20 Bob Griffiths

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Posted 10 May 2014 - 03:17 PM

I also use the original Wing Thing (fr4om S & S Optica) and it fits fine in the cavity of my 8i
I actually like it a "little" better then I do the one JMI sells

Bob G

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#21 mostlyemptyspace

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Posted 20 May 2014 - 01:02 PM

Ok so I bought an Orion 6x30 RACI finder, and it doesn't really do the job. I still need a RDF or Telrad to get me in the neighborhood of the star I'm looking for.

I don't think I want to go with the Telrad because it's bulky and I don't like the idea of the double-sided tape. That being said, which would you guys recommend? The Baader Sky Surfer III, the Orion EZ Finder II, or some other?

#22 Midnight Dan

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Posted 20 May 2014 - 01:49 PM

Hi mostly:

Have you tried just sighting along the outside of the 6x30 finder's optical tube to initially get you in the vicinity of the target alignment star? That finder has a 7° field of view so I would think it wouldn't be too big a problem finding your star.

Also, the view through the finder looks different because you can see more stars than naked eye, and it can sometimes be confusing. It can take some getting used to.

-Dan

#23 mostlyemptyspace

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Posted 20 May 2014 - 02:14 PM

Well the main problem I'm having is that I need to align the RACI in the first place. Whenever I move the thing it goes a little out of whack. So let's say I want to align using Mars, I slew up to where I think it may be, then look down the outside of the finder scope to where I think Mars is, then I look into the RACI and I don't see Mars. I slew around for a while and eventually, after several minutes of looking, I find Mars. I then center it, and then look through my scope using a 25mm EP. I don't see Mars, so I slew around some more, and eventually just get frustrated. The only way I've been able to get the thing aligned is by using the Moon, but on most of my outings the moon won't be visible.

That's why I decided to go back to the RDF.

#24 Midnight Dan

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Posted 20 May 2014 - 02:57 PM

Hi mostly:

Regardless of what kind of finder you use, even an RDF, it has to be aligned with the main scope before you try using it for sky alignment of the mount, or trying to find a target.

The easiest way to do it is during the daytime. Aim the main scope at the most distant target you can see, like the top of a building, telephone pole or tree. Make sure the target is centered as well as you can in the 25mm eyepiece. Then look through the finder and use the adjusting screws so that the cross-hairs are centered on the target. Be sure that the finder is solidly in the base with the base screw tightened so it doesn't shift.

When you go out at night, you should be close to on target. However, the stars are more distant than your daytime target, so the parallax difference will mean you will be off a bit. So you want to tweak the finder alignment at night.

Find a bright target like Mars or Polaris, and center it in the main scope with the 25mm EP. If you grossly defocus the target, it will turn into a large donut which fills much of the view. It's easier to determine if this image is centered, so you can use it to accurately center the target. Then look in the finder and use the adjusting screws to center the finder crosshairs over the target.

Note that if you use Polaris, it will not be moving so you are good to go. However, if you were using Mars, you may want to go back and forth from main scope to finder a couple of time to check alignment because Mars will be moving across the sky over time.

When you're done, you should be accurately aligned and be able to easily use the finder to point the scope where you want, or perform your scope alignment. If you remove the finder and reinstall it, it still should be very close, but you may need to tune up the finder alignment a bit.

-Dan

#25 hamdul

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Posted 20 May 2014 - 05:46 PM

Hi Mostly,
Do it like Dan says. You were doing it backwards

Fred






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