Caroline96
New member
I want to make my own simple binoculars using only two lenses, does anyone know what would be required to make such?
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Has anyone ever made their own binoculars? (1 Viewer)
- Thread starter Caroline96
- Start date
. Hi Caroline. Welcome,
. You would need 2 positive lenses, say 6 inch focal length and then 2 negative lenses, perhaps for somebody with severe shortsightedness.
Then you would have a simple opera glass.
But it would probably have severe aberrations. Colour fringing etc.
Binoculars nowadays have compound, normally two element objectives which are achromatic, and then special prisms that turns the image upright. Then usually nowadays a minimum of three element eyepieces, usually Kelner or similar.
You might find the positive lenses from simple magnifiers. There are ones about 1.5 inches across.
You could use simple cardboard tubes black on the inside preferably.
To experiment, just hold 2 lenses in your hands to see how each barrel works.
The field of view of such a binocular will be very small.
It is quite likely that there are cheap kits to make such a simple binocular.
. You would need 2 positive lenses, say 6 inch focal length and then 2 negative lenses, perhaps for somebody with severe shortsightedness.
Then you would have a simple opera glass.
But it would probably have severe aberrations. Colour fringing etc.
Binoculars nowadays have compound, normally two element objectives which are achromatic, and then special prisms that turns the image upright. Then usually nowadays a minimum of three element eyepieces, usually Kelner or similar.
You might find the positive lenses from simple magnifiers. There are ones about 1.5 inches across.
You could use simple cardboard tubes black on the inside preferably.
To experiment, just hold 2 lenses in your hands to see how each barrel works.
The field of view of such a binocular will be very small.
It is quite likely that there are cheap kits to make such a simple binocular.
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Hi,
that would be what is called galilean binoculars. See the following page for some history and instructions - albeit for a larger example.
http://galileo.rice.edu/lib/student_work/astronomy96/mtelescope.html
Galileans suffer from very small field of view but they show an erect image and so don't need an erecting prism. They were being built as simple, low magnification opera glasses.
Joachim
that would be what is called galilean binoculars. See the following page for some history and instructions - albeit for a larger example.
http://galileo.rice.edu/lib/student_work/astronomy96/mtelescope.html
Galileans suffer from very small field of view but they show an erect image and so don't need an erecting prism. They were being built as simple, low magnification opera glasses.
Joachim
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winwinbino
Well-known member
To DIY a workable "bino"culars is nearly next to impossibe, but some whole-hearted fans made their own astro scope (mono).
WJC
Well-known member
If you conciser your time worth a fraction of minimum wage, don't bother . . . for more reasons than I have time to enumerate.
Cheers,
Bill
There are some folks at www.cloudynights.com who have built them,
usually big astronomical ones.
You would need, at least, two doublet achromats up front,
two roof prism asseblies or 4 porro prisms, eyepieces with
3 elements or more in each, and a lot of tweeking to align the two views.
To make a very simple telescope,
you could use two lenses. Results would be fairly basic, and upside-down.
edwincjones
Well-known member
consider going to the Cloudy Nights forum under Binoculars or ATM section
several there make their own
edj
several there make their own
edj
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Caroline96
New member
Interesting, I'll have to check on Cloudy Nights as well. I noticed that it would be very hard to align lenses, especially if the magnification is large. That's why it might be the best to mill out designed forms into wood or metal and just combine them together with the lenses fit it.
Though the reason why I thought of using 2 lenses was because it would be the most simple and least expensive design. But if the image will have a very narrow FOV and the end result will be an upside down image then it wouldn't be worth it. Something like a rifle scope was what I was aiming for.
What would ya'll suggest for something using an objective lens that's 20 mm in diameter, with the tube of the binoculars being 140 mm long? And what could the maximum magnification for something like that be, could it reach 50x magnification?
Though the reason why I thought of using 2 lenses was because it would be the most simple and least expensive design. But if the image will have a very narrow FOV and the end result will be an upside down image then it wouldn't be worth it. Something like a rifle scope was what I was aiming for.
What would ya'll suggest for something using an objective lens that's 20 mm in diameter, with the tube of the binoculars being 140 mm long? And what could the maximum magnification for something like that be, could it reach 50x magnification?
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. Hi Carolyn,
Yes that is possible.
Edmunds scientific or maybe Surplus Shed? Jaegers used to be very good, but I think they haven't existed for decades.
You need a 20 mm F/6 or F/7 achromatic doublet objective lens maybe in a cell. Possibly from an ex government instrument such as a surveying instrument.
50 times magnification is possible with a very high quality doublet, but the image will be very dim indeed and only suitable for observing perhaps the moon and planets and double stars, and maybe terrestrial objects in very bright light. 40 times is probably more sensible as a maximum magnification.
With 120 mm focal length the eyepiece would need to be 3 mm. There are some long eye relief eyepieces, which you could get. However, the image would be upside down.
There are upright eyepieces available perhaps around 10 mm focal length, which would give a 12×20 instrument.
I would use one of my monocular converters which produces an upright image with an apparent field of view of about 55°. This again is 10 millimetres focus for most of them. Giving a 12×20 scope.
You could use a three times camera lens Tele converter or Barlow lens with the same fitting as the monocular converter which would give 36×20. The exit pupil is only around 0.5 mm, so you must have good eyes without any cataracts et cetera to use this properly. I do routinely use such small exit pupils.
If you intend making it into a binocular you will have very severe problems trying to collimate a 40×20 binocular. You will even have problems trying to collimate a 12×20 binocular.
Yes that is possible.
Edmunds scientific or maybe Surplus Shed? Jaegers used to be very good, but I think they haven't existed for decades.
You need a 20 mm F/6 or F/7 achromatic doublet objective lens maybe in a cell. Possibly from an ex government instrument such as a surveying instrument.
50 times magnification is possible with a very high quality doublet, but the image will be very dim indeed and only suitable for observing perhaps the moon and planets and double stars, and maybe terrestrial objects in very bright light. 40 times is probably more sensible as a maximum magnification.
With 120 mm focal length the eyepiece would need to be 3 mm. There are some long eye relief eyepieces, which you could get. However, the image would be upside down.
There are upright eyepieces available perhaps around 10 mm focal length, which would give a 12×20 instrument.
I would use one of my monocular converters which produces an upright image with an apparent field of view of about 55°. This again is 10 millimetres focus for most of them. Giving a 12×20 scope.
You could use a three times camera lens Tele converter or Barlow lens with the same fitting as the monocular converter which would give 36×20. The exit pupil is only around 0.5 mm, so you must have good eyes without any cataracts et cetera to use this properly. I do routinely use such small exit pupils.
If you intend making it into a binocular you will have very severe problems trying to collimate a 40×20 binocular. You will even have problems trying to collimate a 12×20 binocular.
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