ASSRA Forum › General › Collecting Single Shot Rifles › Happy Birthday to Me - Unertl Scope
(Moderator Group: Moderator)
‹ Previous Topic | Next Topic ›
Page Index Toggle Pages: 1 [2]  Send TopicPrint
Very Hot Topic (More than 25 Replies) Happy Birthday to Me - Unertl Scope (Read 17249 times)
westerner
Frequent Elocutionist
*****
Offline


deleted posts and threads
record holder.

Posts: 11522
Location: Why, out West of course
Joined: May 29th, 2006
Re: Happy Birthday to Me - Unertl Scope
Reply #15 - Dec 7th, 2013 at 6:05pm
Print Post  
Okay, got all that. So the extra eye piece is just an extra? Or you don't know your own self and that's why you can't answer.  One little ole eyepiece, phew!   

    Joe.
  
A blind squirrel runs into a tree every once in a while.
Back to top
 
IP Logged
 
John Boy
Ex Member


Re: Happy Birthday to Me - Unertl Scope
Reply #16 - Dec 7th, 2013 at 6:20pm
Print Post  
Hmmm - check this out ... (You need to Login or Register to view media files and links)
Says the 1 1/2" Target came in a 24X!
  
Back to top
 
IP Logged
 
Chuckster
Frequent Elocutionist
*****
Offline



Posts: 2238
Location: Colorado
Joined: May 15th, 2008
Re: Happy Birthday to Me - Unertl Scope
Reply #17 - Dec 7th, 2013 at 10:42pm
Print Post  
In the process of designing a scope. Numbers say about 15X maximum for an 1.5" objective. Higher magnification and you start to loose brightness on cloudy days or targets in the shade. Any comments?
Chuck
  
Back to top
 
IP Logged
 
westerner
Frequent Elocutionist
*****
Offline


deleted posts and threads
record holder.

Posts: 11522
Location: Why, out West of course
Joined: May 29th, 2006
Re: Happy Birthday to Me - Unertl Scope
Reply #18 - Dec 7th, 2013 at 11:55pm
Print Post  
Lyman made a 30 power 1 1/2" scope. Excellent when the day is bright.  Had to replace one with a 20 power late in the evening at Etna Green. Power is over rated.

     Joe. 

  
A blind squirrel runs into a tree every once in a while.
Back to top
 
IP Logged
 
BP
Frequent Elocutionist
*****
Offline



Posts: 8039
Location: Westside
Joined: Aug 27th, 2006
Re: Happy Birthday to Me - Unertl Scope
Reply #19 - Dec 8th, 2013 at 3:22am
Print Post  
Chuck,

(You need to Login or Register to view media files and links)

  
There are three kinds of men: The ones that learn by reading, the few who learn by observation, and the rest who have to pee on the electric fence and find out for themselves.
Proud Noodlehead
Back to top
 
IP Logged
 
Chuckster
Frequent Elocutionist
*****
Offline



Posts: 2238
Location: Colorado
Joined: May 15th, 2008
Re: Happy Birthday to Me - Unertl Scope
Reply #20 - Dec 8th, 2013 at 12:09pm
Print Post  
Thanks for the comments. Excellent website. Interesting statement: "Human eye has maximum resolution with an exit pupil of between 2 and 3 mm."

Sorry, John. Did not mean to hijack. That is a beautiful and excellent scope and the two different eyepieces make it better. Don't have to change scopes, just eyepiece.
Chuck
  
Back to top
 
IP Logged
 
John Boy
Ex Member


Re: Happy Birthday to Me - Unertl Scope
Reply #21 - Dec 8th, 2013 at 12:44pm
Print Post  
Gents - Hijack at will!  The more we learn about these scopes the more educated we become, especially me.

OK, something I have never seen in the reference books that I have about scopes.  So, go back to the link above ... 
(You need to Login or Register to view media files and links)

Look at the information that Dewy Greiner has on his site for all the Unertl scope models ... Power - Field (ft) & Lumens

Because both the oculars on the Unertl are not stamped and not a whiz bang with math - I'm going to take the oculars to my friendly optometrist and have him measure the power of each 

  
Back to top
 
IP Logged
 
Chuckster
Frequent Elocutionist
*****
Offline



Posts: 2238
Location: Colorado
Joined: May 15th, 2008
Re: Happy Birthday to Me - Unertl Scope
Reply #22 - Dec 8th, 2013 at 2:02pm
Print Post  
Don't know what to do with Lumens, but looks like it has to do with the square of the exit pupil. Double the magnification and get 1/4th the Lumens or measure of brightness.

Have your friendly optometrist measure the focal length of the oculars or use Frank's method. If you know one makes the scope 20X, then the magnification with the other one can probably be calculated. 
Chuck
  
Back to top
 
IP Logged
 
John Boy
Ex Member


Re: Happy Birthday to Me - Unertl Scope
Reply #23 - Dec 8th, 2013 at 4:02pm
Print Post  
Quote:
Don't know what to do with Lumens, but looks like it has to do with the square of the exit pupil.

(You need to Login or Register to view media files and links))
Quote:
The lumen (symbol: lm) is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power (radiant flux) in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all electromagnetic waves emitted, independent of the eye's ability to perceive it. A lux is one lumen per square meter.
  
Back to top
 
IP Logged
 
BP
Frequent Elocutionist
*****
Offline



Posts: 8039
Location: Westside
Joined: Aug 27th, 2006
Re: Happy Birthday to Me - Unertl Scope
Reply #24 - Dec 8th, 2013 at 5:55pm
Print Post  
On the 2nd page of the pdf, in the 2nd paragraph under the topic Brightness, the author D.R. Wulfinghoff states:

"The light could be reflected or transmitted. For example, the bright surface could be the surface of a fluorescent tube, a page of a book, a window with a view of the sky, or a store window with reflections." 

Sounds good to me... the target we want to see is much like a paper page of a book, the light provided by the sun is reflected off the target and transmitted to our eye through the lenses in our scope.

(You need to Login or Register to view media files and links)

  
There are three kinds of men: The ones that learn by reading, the few who learn by observation, and the rest who have to pee on the electric fence and find out for themselves.
Proud Noodlehead
Back to top
 
IP Logged
 
John Boy
Ex Member


Re: Happy Birthday to Me - Unertl Scope
Reply #25 - Dec 8th, 2013 at 7:56pm
Print Post  
Quote:
Footcandles and Lux
“Footcandles” and “lux” are units that indicate the
density of light that falls on a surface. This is what light
meters measure. For example, average indoor lighting
ranges from 100 to 1,000 lux, and average outdoor
sunlight is about 50,000 lux

"I was at the range and the light wasn't too good, it was only 30,000 lux.  Every range box needs a lux meter and posting 'it was cloudy' is now passe  Wink 

I presume also, one can put the meter in front of the scope and measure how well it gathers outside light
  
Back to top
 
IP Logged
 
BP
Frequent Elocutionist
*****
Offline



Posts: 8039
Location: Westside
Joined: Aug 27th, 2006
Re: Happy Birthday to Me - Unertl Scope
Reply #26 - Dec 8th, 2013 at 9:24pm
Print Post  
John Boy,

Is that 3.6 lumens shown on the unertl36.htm page for the 1 1/2" 20x Targetscope obtained with outdoor sunlight at 50,000 lux, or at 30,000 lux?
        Grin

  
There are three kinds of men: The ones that learn by reading, the few who learn by observation, and the rest who have to pee on the electric fence and find out for themselves.
Proud Noodlehead
Back to top
 
IP Logged
 
John Boy
Ex Member


Re: Happy Birthday to Me - Unertl Scope
Reply #27 - Dec 12th, 2013 at 4:20pm
Print Post  
westerner wrote on Dec 7th, 2013 at 6:05pm:
Okay, got all that. So the extra eye piece is just an extra? Or you don't know your own self and that's why you can't answer.  One little ole eyepiece, phew!  
    Joe.

Update to respond to Joe's post:
*  Found in my references - Cornell Publication's - 1956 Unertl Catalog reprint, 37 pages with all one wants to know about Unertl's
*  They list Interchangeable High & Low Power Eye-Pieces for their scopes to increase or decrease power:
(You need to Login or Register to view media files and links)

Turn the page-pg 30, Unertl 1 1/2" Target Scope.  I applied the two eyepiece's power increase & decrease to my 20x scope:
20x < 35% = 13x ... the lower power eye piece
20x > 35% = 27x ... the higher power eye piece
(You need to Login or Register to view media files and links)

Turn the page - pg 36, Physical and Optical Propertied. and Dimensions of Unertl Scopes ... including 1956 prices

(You need to Login or Register to view media files and links)

In 1956, one could buy the 1 1/2, 20x - 25" tube & extra eye piece for $97.50.  Inflation adjusted from 1956 to 2013, the scope & eye piece is $836.16 (758.6%).  Guess I found a deal - I paid $395 plus $15 shipping ... a real Happy Birthday To Me! 
Turn myself in at the nearest police station?
Nope Red, going be a fugitive for this purchase Lips Sealed
« Last Edit: Dec 12th, 2013 at 4:26pm by »  
Back to top
 
IP Logged
 
gunlaker
Frequent Elocutionist
*****
Offline



Posts: 2331
Location: lower mainland, B.C.
Joined: Dec 13th, 2010
Re: Happy Birthday to Me - Unertl Scope
Reply #28 - Dec 12th, 2013 at 5:28pm
Print Post  
Thanks for that reference John.  I'll have to get that reprint.

Chris.
  
Back to top
 
IP Logged
 
Fritz
Oldtimer
*****
Offline



Posts: 516
Location: Texas
Joined: Jun 27th, 2008
Re: Happy Birthday to Me - Unertl Scope
Reply #29 - Dec 12th, 2013 at 7:24pm
Print Post  
Thanks John,this is great info on these Unertl scopes Regards--Fritz
  
Back to top
YIM  
IP Logged
 
Page Index Toggle Pages: 1 [2] 
Send TopicPrint
‹ Previous Topic | Next Topic ›
 
  « Board Index ‹ Board Top  

ASSRA Forum » Powered by YaBB 2.6.12!
YaBB Forum Software © 2000-2024. All Rights Reserved.

Valid RSS Valid XHTML Valid CSS Powered by Perl Source Forge

Page completed in 0.4464 seconds.