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Jaegers lens question

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#1 Spacechicken

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Posted 24 May 2019 - 08:11 PM

Hi folks,

 

A while back I got my hands on a box of new old stock Jaegers lenses from 1958. I've got a matches set of 6" f15 lenses and 10-2" lenses that I think might have been destined to become eyepieces. Can anyone offer some insight into whether the lenses listed below would be suitable for eyepeices and where I might find some instruction as to how to go about arranging them.

I have as follows,

4- 54mm f1 300 mm   #1112

3- 54mm f1 254 mm  #1476

3- 59mm f1 308 mm  #1496

I'm familiar with vintage Tasco refractors and own a couple of reflectors that see most of the use. I'd like to use the lenses to build a classic Jaeger planetary telescope.

 

Thanks in advance, Beth



#2 BGRE

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Posted 24 May 2019 - 08:28 PM

None of those lenses are likely to be useful in an eyepiece for a telescope unless you intend to emulate Hevelius' telescope.

The focal lengths are too long to be useful for a 6" F/15 telescope. A maximum eyepiece focal length or around 75mm (for a 5mm eye pupil diameter) is required to  ensure that the entire 6" aperture is used and not stopped down by the edges of the eye pupil. 


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#3 NinePlanets

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Posted 24 May 2019 - 08:33 PM

Those lenses were very likely destined to be objective lenses for items like binoculars, gun sights, or finder scopes.


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#4 Spacechicken

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Posted 24 May 2019 - 09:09 PM

Thanks for the quick feedback.


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