Jump to content


Photo

Rigel or Telrad?

  • Please log in to reply
25 replies to this topic

#1 Heim

Heim

    Lift Off

  • -----
  • Posts: 21
  • Joined: 04 Jun 2014
  • Loc: NW Florida

Posted 24 June 2014 - 10:56 AM

I'm sure this is a century old debate, but I would appreciate some opinions. For my 8" dob, I was thinking of replacing my 8x50 scope with a telrad, then I looked into rigel and liked how it's lighter, and runs on lithium batteries since I can buy them in bulk for my lazer collimator as well.

So what does everyone suggest? I've never tried one or the other, so I can't base a decision off experience. Thank you :jump:

#2 youngamateur42

youngamateur42

    Surveyor 1

  • *****
  • Posts: 1855
  • Joined: 21 Nov 2012
  • Loc: La Verne, CA

Posted 24 June 2014 - 11:04 AM

A Telrad AND your 8x50 finder combination is pretty optimal, because when your looking for a faint object, you need to reference the fainter stars that your finder shows, with the fast aiming of the Telrad make it the best choice.

#3 paul hart

paul hart

    Apollo

  • *****
  • Posts: 1249
  • Joined: 01 Jun 2004
  • Loc: Long Island, New York

Posted 24 June 2014 - 11:11 AM

A Telrad AND your 8x50 finder combination is pretty optimal, because when your looking for a faint object, you need to reference the fainter stars that your finder shows, with the fast aiming of the Telrad make it the best choice.


I'll second that. I own both and use the Rigel on the smaller scope. I prefer the Telrad where possible because unlike the Quik Finder there is very little parallex, and the batteries on the Telrad last just about forever.

#4 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 44359
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 24 June 2014 - 11:19 AM

So what does everyone suggest? I've never tried one or the other, so I can't base a decision off experience.



If your skies are dark, dark enough to see the Milky Way without strain, then replacing your magnifying finder with a Telrad or Rigel is reasonable. Otherwise, there are not enough guide stars visible to use a non-magnifying finder.

As Justin and Paul have said, both an 8x50 and a Telrad/Rigel are best, that's what I do. I very much prefer the Telrad, the 4 degree ring is a big help as is the much reduced parallax error. The long battery life is also a bonus. If you forget to turn it off, it will run for months...

The question is whether there is enough room for both the Telrad and a magnifying finder. If not, then the Rigel maybe a better choice.

Jon

#5 Heim

Heim

    Lift Off

  • -----
  • Posts: 21
  • Joined: 04 Jun 2014
  • Loc: NW Florida

Posted 24 June 2014 - 11:30 AM

Telrad it is. Seems the lithium battery idea is a mute point when AA last forever in the telrad. My fan uses AA anyway, so shouldn't be hard sparing some if the telrad ever needs them. Thanks!

#6 StarStuff1

StarStuff1

    Soyuz

  • *****
  • Posts: 3893
  • Joined: 01 Apr 2007
  • Loc: South of the Mason-Dixon Line

Posted 24 June 2014 - 11:43 AM

For almost 2 decades I used a Telrad. Worked fine. The only thing I didn't like was the bulk.

An 8-in Celestron dob moved into my arsenal and there was a need for another reflex finder. There really was not enough room for a Telrad so I bought a new Rigel. I really like it. The knob that turns on the unit was small so I put a rubber tip on it. A few years after I got it the battery finally failed. It has a coin shaped 2032 battery. Since I was observing and didn't want to run to the store I took a battery holder for 2 AAAs and modified it to the Rigel.

My only real complaint about the Rigel is that it seems less robust than the Telrad.

Attached Files



#7 StarStuff1

StarStuff1

    Soyuz

  • *****
  • Posts: 3893
  • Joined: 01 Apr 2007
  • Loc: South of the Mason-Dixon Line

Posted 24 June 2014 - 11:45 AM

The above pic was the "cobbled up version I did that night. The next day I made a batter cover and re-routed the wires.

Attached Files



#8 Heim

Heim

    Lift Off

  • -----
  • Posts: 21
  • Joined: 04 Jun 2014
  • Loc: NW Florida

Posted 24 June 2014 - 11:51 AM

Looking sharp :grin:

#9 rockethead26

rockethead26

    Gemini

  • *****
  • Posts: 3422
  • Joined: 21 Oct 2009
  • Loc: Arizona, USA

Posted 24 June 2014 - 12:04 PM

I had eye placement issues with the Rigel and went back to the Telrad. I really liked the smaller size of the Rigel, but it was literally a pain in the neck for me because it took me so long to find the projected reticle.

#10 AMerritt

AMerritt

    Explorer 1

  • -----
  • Posts: 72
  • Joined: 05 Nov 2006

Posted 24 June 2014 - 03:36 PM

Exactly so about there being enough room! On my smaller scope, the XT10, I use a Rigel placed in between focuser and 9x50 finder, a Telrad is a tighter fit, plus a little more back strain to get the angle under it, however, I have often seen the Telrad mounted on the other side of the 9x50 finder or on the left of the focuser. Like the others said, do not replace the 8x50 - not only guide stars but faint nebulosity can guide you!

#11 Dodge2013

Dodge2013

    Mariner 2

  • *****
  • Posts: 225
  • Joined: 05 Jan 2014
  • Loc: Jackson, Tennessee

Posted 24 June 2014 - 09:42 PM

If anyone is interested go to Astrosystems.biz and look at their offerings of the Telrad and Rigel. Especially the dew shield for the Telrad. They also have a Rigel with external battery pack. I just happened on this sight.

#12 Dadadee

Dadadee

    Ranger 4

  • -----
  • Posts: 388
  • Joined: 05 Dec 2013
  • Loc: Near Montreal, Qc, Canada

Posted 25 June 2014 - 12:29 AM

I concur with Jon. Both is the way to go. Telrad is limited in heavier light pollution. But still useful. But I could not go without my 9x50 RACI finder

#13 Hesiod

Hesiod

    Viking 1

  • -----
  • Posts: 537
  • Joined: 13 Jan 2013

Posted 25 June 2014 - 04:52 AM

I agree with Jon Isaacs too, use them together.
I am a Telrad supporter, but if there is not enough room to place it near the finderscope, then go for the Rigel.
I have both (can not place the Telrad on my 4" ED because is too long) and in my opinion there is not a lot of difference between them (unless you really need the 4° circle); Rigel has a built-in pulser, very nice, but feels more brittle.

#14 nicknacknock

nicknacknock

    Viking 1

  • *****
  • Posts: 740
  • Joined: 20 Feb 2012
  • Loc: In a galaxy far far away...

Posted 25 June 2014 - 07:10 AM

Just tried the Rigel the last couple of sessions with my 5" frak. All I can say is that I am reverting to a Telrad ASAP. It may be bulky, it may be heavy, but it is still the best option if you have enough room to mount it.

The Rigel strikes me as a very cheap construct. It displays extreme parallax effect and it is uber sensitive to eye placement relative to the tiny window.

Now, why can't someone make a Telrad which is not so long (yes, you can hack nearly half of it off, but I am as technically inclined as a Smurf).

#15 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 44359
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 25 June 2014 - 09:18 AM

Now, why can't someone make a Telrad which is not so long (yes, you can hack nearly half of it off, but I am as technically inclined as a Smurf).



The length is the reason that there is minimal parallax error. That and the space for the AA batteries. But the I have never found the length to be a problem, if need be, I just let the Telrad stick out past the end of the scope.

I recently purchased a Scopestuff Telrad mount that fits the Vixen/Orion/Celestron/Skywatcher finder shoe. It works well with my NP-101 refractor, very sweet. The dovetail doesn't fit all my scopes though, I am going to have to do some grinding.

Jon

#16 AMerritt

AMerritt

    Explorer 1

  • -----
  • Posts: 72
  • Joined: 05 Nov 2006

Posted 25 June 2014 - 11:06 AM

That is a MUCH better option than the Televue Qwik Point Finder which I found way too small to be useful on my NP-101.

#17 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 44359
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 25 June 2014 - 12:58 PM

That is a MUCH better option than the Televue Qwik Point Finder which I found way too small to be useful on my NP-101.


I find a simple red dot finder is quite effective with my NP-101, I use it in conjunction with the 35mm Pan or 31mm Terminagler.

I purchased the Scopestuff Vixen-Telrad mount so I could use the NP-101 as a remote, unmounted finder scope for my large Dob.. The refractor is on it's own alt-az mount. I find the object or specific region with the NP-101, then I match the Telrad images to point the big scope. I also work the other way, find something interesting in the big scope and then see if I can see it in the smaller scope. Electronic charts with Telrad circles are helpful but there is nothing quite like the naked eye view.

Jon

#18 Starman81

Starman81

    Vanguard

  • *****
  • Moderators
  • Posts: 2055
  • Joined: 06 Mar 2008
  • Loc: Metro Detroit, MI, USA

Posted 25 June 2014 - 03:25 PM

Exactly so about there being enough room! On my smaller scope, the XT10, I use a Rigel placed in between focuser and 9x50 finder, a Telrad is a tighter fit, plus a little more back strain to get the angle under it, however, I have often seen the Telrad mounted on the other side of the 9x50 finder or on the left of the focuser. Like the others said, do not replace the 8x50 - not only guide stars but faint nebulosity can guide you!


I will readily admit that the Telrad is superior but I agree with the points mentioned above. On an 8", there isn't much real estate for a Telrad + 9x50 and the longer body will also make you contort your body more to be able to get a view through it. Also, by design, the Rigel has a built-in 'riser', but it can be tricky to find the reticle at times and there is parallax.

So with an 8", Rigel is more suitable, though a compromise. Personally, I use Multi-Reticle finders on my 8"ers, without any optical aid (8, 9x50). It makes for some lengthy, character-building star hops in the less than dark skies (SQM 19.5) I often find myself observing in!

#19 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 44359
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 25 June 2014 - 04:06 PM

Also, by design, the Rigel has a built-in 'riser', but it can be tricky to find the reticle at times and there is parallax.



Looks can be deceiving, the height of the Telrad and the Rigel reticule are, for all practical purple shirt, identical.

Jon

#20 GeneT

GeneT

    Ely Kid

  • *****
  • Posts: 12790
  • Joined: 07 Nov 2008
  • Loc: South Texas

Posted 25 June 2014 - 05:44 PM

I like the Telrad over the Rigel. If your telescope can handle it, consider using both the optical and Telrad. They complement each other.

#21 chemtchr

chemtchr

    Explorer 1

  • -----
  • Posts: 60
  • Joined: 24 Jun 2011
  • Loc: Central Ohio

Posted 26 June 2014 - 08:32 AM

Definitely use both as many have stated already. If your optical finder is not RACI, then I would consider replacing it with a RACI finder and using it with the Telrad/Rigel. If, however, you are accustomed to using an image-inverted finder, then stick with it. The advantage of the RACI finder is it matches the chart views. Very handy.

Paul

#22 Thomas Karpf

Thomas Karpf

    Surveyor 1

  • -----
  • Posts: 1769
  • Joined: 09 Feb 2009
  • Loc: Newington, CT

Posted 26 June 2014 - 11:01 AM

If anyone is interested go to Astrosystems.com and look at their


I think you mean http://www.astrosystems.biz/

#23 AMerritt

AMerritt

    Explorer 1

  • -----
  • Posts: 72
  • Joined: 05 Nov 2006

Posted 26 June 2014 - 11:21 AM

Last night using my XT10 after a long hiatus - I would now recommend the Telrad - had a hard time getting the right view through the reticle on this small a scope. (have very long legs, so this may not be an issue for everyone!!) One can also get riser extenders for the Telrad to raise it up - and I am going to place the Telrad so it extends over tube and not flush for more height.

#24 JMW

JMW

    Surveyor 1

  • -----
  • Posts: 1504
  • Joined: 11 Feb 2007
  • Loc: Nevada

Posted 26 June 2014 - 12:23 PM

I use multiple scopes at the same time. I like having a Telrad on each so I can match up the Telrads on the different scopes once I find the object on one scope. I think a Telrad is the only solution for a dob that needs a ladder since you can see it while several feet behind it. The Rigel requires that you are fairly close to it to use it.

#25 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 44359
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 26 June 2014 - 01:52 PM

I think a Telrad is the only solution for a dob that needs a ladder since you can see it while several feet behind it.



:waytogo:

One could mount a Rigel nearer the mirror end of the scope but with a scope large enough to require a ladder, there should be plenty of real estate to mount a Telrad. The Telrad is handy for initially pointing the scope because you can do it while standing on the ground. That makes it much easier to position the ladder.

Jon






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics