Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Who made the first commercial RDF designed for telescopes?

  • Please log in to reply
16 replies to this topic

#1 Terra Nova

Terra Nova

    ISS

  • *****
  • topic starter
  • Posts: 24,781
  • Joined: 29 May 2012
  • Loc: 39.07°N, 229m AMSL, USA

Posted 03 June 2021 - 10:49 AM

Who made the first commercial RDF designed for telescopes? Was it the TeleVue Starbeam, the Telrad or something else. It seems that I remember the first one I ever saw was an early Starbeam without the mirror. Apogee also marketed a Mars Eye back in the 90s and Scopetronix had one. I forget exactly when the Telrad came out. IMO, Telrads work great but are uglier than a one-eyed, swayback horse. I’ve had three Telrads in the past but none presently. I’ve also had a Starbeam that I sold. Both were just too big and heavy to suit me. I like small, light, compact RDFs. The Baader is a bit bigger and is a favorite of mine. And at some point there could definitely be another Telrad in my future. After all, I’ve fallen for them three times before. Another Starbeam, probably not. Anyway, what do you remember as the earliest one, and do you like them.

 

My dirty little secret: I really enjoy RDFs and GLPs on my scopes, paired with handheld binoculars over telescopic finders. blush.gif


Edited by Terra Nova, 03 June 2021 - 12:11 PM.

  • ArizonaScott, brian dewelles, Bomber Bob and 5 others like this

#2 Defenderslideguitar

Defenderslideguitar

    Gemini

  • *****
  • Posts: 3,227
  • Joined: 05 Oct 2016
  • Loc: Connecticut

Posted 03 June 2021 - 11:14 AM

Good question

 

I am not sure. It seems like the TV Starbeam was the first I ever saw.  Yes   I like the  red bullseye of the telrads but you are right that they seem clunky     I  have  a rdf on the C-102fl now   i liked the original finder but with the moonlite focuser the rdf is easy peasy and not in the way.....

 

 

Sometimes original focusers do the job and look correct and are just right    other times    I knock them of the cross mark being my clumsy self   or oddly some are located just in the wrong spot and are forhead knockers


  • Terra Nova and oldmanastro like this

#3 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 92,642
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 03 June 2021 - 11:22 AM

Lew Chilton's: The Telrad Story Invented 1977, definitely in production by 1981 and probably earlier

 

https://astronomycon...telrad-story.5/

 

Televue Timeline: Starbeam 1991

https://www.televue....d=13&Tab=_chron

 

jon


  • brian dewelles, Terra Nova, kansas skies and 6 others like this

#4 Terra Nova

Terra Nova

    ISS

  • *****
  • topic starter
  • Posts: 24,781
  • Joined: 29 May 2012
  • Loc: 39.07°N, 229m AMSL, USA

Posted 03 June 2021 - 12:07 PM

Thanks for those links Jon. I’d forgotten about the TeleVue Timeline and hadn’t read the piece in Astronomy Connect. That’s a great story Lew wrote. I really enjoyed reading it. How about that! The Telrad predated the Starbeam by more than ten years! As Beaver Cleaver used to say: “Who woulda thunk!”



#5 DAVIDG

DAVIDG

    Voyager 1

  • *****
  • Posts: 10,251
  • Joined: 02 Dec 2004
  • Loc: Hockessin, De

Posted 03 June 2021 - 12:50 PM

 Actually the US military beat them all during WWII I have a couple of gun sites that used the technology. Also back in 1972 Sky and Tel ran an article by Bob Cox were he had designs for a number of them. Cox helped develop one used in the Mercury spacecraft. I bet it the inventor of the Telrad saw  that article and helped him with his design of his version. 

 

                 - Dave 


  • Terra Nova, Bomber Bob, Augustus and 1 other like this

#6 clamchip

clamchip

    Voyager 1

  • *****
  • Posts: 11,365
  • Joined: 09 Aug 2008
  • Loc: Seattle

Posted 03 June 2021 - 02:19 PM

For a telescope maybe Telrad? Telrad goes back to the late 1970's.

I'll never forget when I first saw a Telrad.

I thought it was the neatest thing, and I still do.

Another great bull's eye reflex sight is the Rigel QuickFinder.

As for RDF finders I use the Orion Easy Finder and like these too but

don't care for the dot covering the star and then some, its annoying at

 high power. A person can adjust the dot a mole's nostril hair away from

the star which is what I do.

The current Easy Finder is the Easy Finder II and I think with the dot

at min intensity it's still a little bright, a pulse would be nice.

I have a vintage original Easy Finder that could be one of the first and

it has a very faint dot, I like it much better.  

I've tried gun sight RDF's and these also have a unacceptably large

dot for astronomy, in my opinion.

 

Robert


Edited by clamchip, 03 June 2021 - 02:25 PM.

  • Terra Nova and Defenderslideguitar like this

#7 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 92,642
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 03 June 2021 - 04:13 PM

 Actually the US military beat them all during WWII I have a couple of gun sites that used the technology. Also back in 1972 Sky and Tel ran an article by Bob Cox were he had designs for a number of them. Cox helped develop one used in the Mercury spacecraft. I bet it the inventor of the Telrad saw  that article and helped him with his design of his version. 

 

                 - Dave 

 

If you read my link to Lew Chilton's story of the Telrad, you'll see that Steve Kufeld saw a gun sight at a surplus store:

 

"On the day that Steve and I were walking the aisles of C&H, he stopped and picked up an olive drab-colored anti-aircraft reflex gun sight from a table and looked it over. I could almost see the wheels turning in his head. He purchased it and took it home where he disassembled and studied it. Within a month or two, he had drafted, bread boarded and produced a prototype that incorporated its zero-power, parallax-free projected bulls-eye principle. And thus was born the Telrad, although it didn’t have a name at first. That happened a few weeks later."

 

Jon


  • Terra Nova and Augustus like this

#8 Terra Nova

Terra Nova

    ISS

  • *****
  • topic starter
  • Posts: 24,781
  • Joined: 29 May 2012
  • Loc: 39.07°N, 229m AMSL, USA

Posted 03 June 2021 - 04:56 PM

For a telescope maybe Telrad? Telrad goes back to the late 1970's.

I'll never forget when I first saw a Telrad.

I thought it was the neatest thing, and I still do.

Another great bull's eye reflex sight is the Rigel QuickFinder.

As for RDF finders I use the Orion Easy Finder and like these too but

don't care for the dot covering the star and then some, its annoying at

 high power. A person can adjust the dot a mole's nostril hair away from

the star which is what I do.

The current Easy Finder is the Easy Finder II and I think with the dot

at min intensity it's still a little bright, a pulse would be nice.

I have a vintage original Easy Finder that could be one of the first and

it has a very faint dot, I like it much better.  

I've tried gun sight RDF's and these also have a unacceptably large

dot for astronomy, in my opinion.

 

Robert

I have this one from Agena:

 

https://agenaastro.c...style-base.html

 

The thing I like about it is that you can switch reticles- cross hairs, circle, circle in cross hairs, etc. you can also vary the brightness with click stops. It’s also very well made and all metal. It’s heavy for its size. The one thing I dislike about, and this is BIG, it is that you have to make the altitude and azimuth adjustments with a tiny Allen wrench which is a PITA in the dark!


Edited by Terra Nova, 03 June 2021 - 04:59 PM.

  • Jon Isaacs and GreyDay like this

#9 Pezdragon

Pezdragon

    Ranger 4

  • *****
  • Posts: 381
  • Joined: 10 Jun 2013
  • Loc: Bay Area, Ca.

Posted 03 June 2021 - 05:10 PM

Back in the seventies I used a reflex sight from a B-17 twin 50 caliber tail gun. I verified this when I toured a fully restored B-17 a few years ago and saw same unit on it’s tail gun. It worked really well but was a bit larger than it needed to be…I wish I never got rid of it….I think it projected a sharper point than the Telrad but probably cost the government a ton of money.


  • Terra Nova likes this

#10 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 92,642
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 03 June 2021 - 05:15 PM

I have this one from Agena:

 

https://agenaastro.c...style-base.html

 

The thing I like about it is that you can switch reticles- cross hairs, circle, circle in cross hairs, etc. you can also vary the brightness with click stops. It’s also very well made and all metal. It’s heavy for its size. The one thing I dislike about, and this is BIG, it is that you have to make the altitude and azimuth adjustments with a tiny Allen wrench which is a PITA in the dark!

 

I have one like that for my NP-101. It's really too bright for dark skies but oh well.  It is nicely made and as Terra says, aligning it is no fun but with a refractor, Collimation doesn't shift so it's pretty much one time and you're done.

 

I just bought a similar one on Amazon, red and green, 5 brightness each. Unfortunately, it had 5 positions each color but they're all equal in brightness. It's going back, hopefully the replacement will be OK.

 

Jon


  • Terra Nova likes this

#11 jwaldo

jwaldo

    Smart Mime

  • *****
  • Posts: 4,042
  • Joined: 26 Apr 2004
  • Loc: Columbia, SC

Posted 03 June 2021 - 05:58 PM

I have this one from Agena:

 

https://agenaastro.c...style-base.html

 

The thing I like about it is that you can switch reticles- cross hairs, circle, circle in cross hairs, etc. you can also vary the brightness with click stops. It’s also very well made and all metal. It’s heavy for its size. The one thing I dislike about, and this is BIG, it is that you have to make the altitude and azimuth adjustments with a tiny Allen wrench which is a PITA in the dark!

Stellarvue used to sell these with uncoated windows, for brighter stars and a dimmer reticle. I have one, and it's the only RDF I've found that can dim as well as a Telrad. Still has those awful Allen key adjustments though!


  • Terra Nova and GreyDay like this

#12 clamchip

clamchip

    Voyager 1

  • *****
  • Posts: 11,365
  • Joined: 09 Aug 2008
  • Loc: Seattle

Posted 03 June 2021 - 06:35 PM

The Rigel QuickFinder goes way back pretty early I would think.

It has a small footprint which I like, a bull's eye, quick detach, and a pulse light

feature. 

Rigel Systems was founded in 1984. The Rigel QuickFinder must have appeared

shortly after that date. Here's some history:

https://www.rigelsys...ist_rig_sys.pdf

Robert

 

post-50896-0-23788400-1488494019_thumb.jpg


Edited by clamchip, 03 June 2021 - 06:52 PM.


#13 GreyDay

GreyDay

    Viking 1

  • -----
  • Posts: 502
  • Joined: 28 Nov 2013
  • Loc: Southport UK

Posted 03 June 2021 - 08:13 PM

My dirty little secret: I really enjoy RDFs and GLPs on my scopes, paired with handheld binoculars over telescopic finders. blush.gif

I use RDF's on all my sub 3" scopes, usually the synta style which i have quite a few of. They're cheap and cheerful and the batteries last forever as long as you remember to switch them off when not in use. I've had to replace the on/off/brightness pots on a few as they do fail, but replacements are really cheap.

 

I've only used a Telrad once and i liked it, but just haven't got round to buying one. Most of my classics wouldn't support the extra bulk smile.gif


Edited by GreyDay, 03 June 2021 - 08:14 PM.

  • Terra Nova and Bomber Bob like this

#14 brian dewelles

brian dewelles

    Explorer 1

  • *****
  • Posts: 95
  • Joined: 09 Nov 2009
  • Loc: Wickenburg AZ.

Posted 03 June 2021 - 09:44 PM

Telrads are useful on all my scopes. Perhaps most useful on big newtonians with its big bright reticle i can aim scope with my feet on the ground, then climb step ladder to the focuser and if i aimed well or i'm lucky, the object will be in or near the field of view. The large reticle is easy to view from several feet.

In the mid 90's i worked part time at a store in phoenix called the astronomy shop. We had a running joke that their was a star party over the weekend with twenty scopes and 15 had telrads and that the following monday morning the five guys that did'nt have them were at the store to buy a telrad. I own three right now.


Edited by brian dewelles, 03 June 2021 - 09:45 PM.

  • Jon Isaacs, Terra Nova and GreyDay like this

#15 DAVIDG

DAVIDG

    Voyager 1

  • *****
  • Posts: 10,251
  • Joined: 02 Dec 2004
  • Loc: Hockessin, De

Posted 04 June 2021 - 09:09 AM

If you read my link to Lew Chilton's story of the Telrad, you'll see that Steve Kufeld saw a gun sight at a surplus store:

 

"On the day that Steve and I were walking the aisles of C&H, he stopped and picked up an olive drab-colored anti-aircraft reflex gun sight from a table and looked it over. I could almost see the wheels turning in his head. He purchased it and took it home where he disassembled and studied it. Within a month or two, he had drafted, bread boarded and produced a prototype that incorporated its zero-power, parallax-free projected bulls-eye principle. And thus was born the Telrad, although it didn’t have a name at first. That happened a few weeks later."

 

Jon

 Jon,

    Yes I did see that. Here are pictures of the one of a couple WWII RDF I have. It still  works. It uses a 1.5 volt D cell. The brightness is adjustable and has a number of color filters that you can place in the light path including an adjustable polarizer. 

   I'm also willing to bet that Kulfield read the Bob Cox Sky and Telescope article on RDF's  since  one of designs is the same has a Telrad. 

 

                     - Dave 

 

wwii sight 1.jpg

wwii sight 2.jpg

wwii sight 3.jpg


Edited by DAVIDG, 04 June 2021 - 09:12 AM.

  • Bomber Bob, jcruse64 and telesonic like this

#16 photoracer18

photoracer18

    Skylab

  • *****
  • Posts: 4,191
  • Joined: 02 Sep 2013
  • Loc: Martinsburg, WV

Posted 04 June 2021 - 03:17 PM

I have this one from Agena:

 

https://agenaastro.c...style-base.html

 

The thing I like about it is that you can switch reticles- cross hairs, circle, circle in cross hairs, etc. you can also vary the brightness with click stops. It’s also very well made and all metal. It’s heavy for its size. The one thing I dislike about, and this is BIG, it is that you have to make the altitude and azimuth adjustments with a tiny Allen wrench which is a PITA in the dark!

Those are basically repurposed red dot gunsights, ones not made bright enough for daylight use. Cheap red dot gunsights I might add. This style normally sell in the shooting sports for $30-40. Almost no one except rookies use these type of sights however. A serious RD for shooting will run you from $200- $500 or more. That is where all the different reticles they come with are used for.


  • Augustus likes this

#17 clamchip

clamchip

    Voyager 1

  • *****
  • Posts: 11,365
  • Joined: 09 Aug 2008
  • Loc: Seattle

Posted 06 June 2021 - 05:11 PM

I found this article on reflex/red dot finders:

https://www.cloudyni...ts/9finders.pdf

 

Robert


  • Terra Nova and telesonic like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics