Binoculars As A Zoom Lens

It may seem trivial at first, but the effect [Dan] gets when using binoculars as a telephoto lens is surprising. The images are well in focus with great colors. This technique not only brings your subject mater closer but also provides a depth-of-focus feature not normally available on simple cameras or camera phones.

The proof is in the example footage found after the break, but you’ll also find a video tutorial detailing the build. [Dan] already had the expensive components are a pair of mini binoculars and a Kodak Zx3 pocket camcorder. The camcorder is the same form factor as a smart phone so using different hardware will be a breeze. He started off by building a prototype out of paper. Basically it’s a bracket that properly aligns the camera with one lens of the binoculars. Once he had everything lined up he transferred his measurements to some sheet metal. The bracket for the binoculars is attached to the one for the camera using bolts and wing nuts to make it adjustable. One important part of the design is to gut a hole for access to the binocular focus wheel.

Example footage:

Build tutorial:

21 thoughts on “Binoculars As A Zoom Lens

  1. I tried something very similar many year ago. My results were horrible. Massive vignetting around the edges. The colors were so washed out it looked sepia. If only I had thought to name it something the kids would like… insta something.

    Dan’s results, on the other hand, are excellent. It looks like the key may be to have a camera lens that is far smaller than than the binocular eyepiece.

  2. im more impressed with his unicycle skills… i consider myself pretty good, but he is just amazing.
    Might also be pretty cool if he could hook up two cameras, and have a 3d zoom lense

  3. all i saw in the video is how to make it. there is no explanation as to how this ‘binocular holder’ relates to the camera. how does he pull focus with it? what holds the camera in relation to the binoculars?

    the results are great, but i’m left with more questions than answers…

    1. You can get zoom binoculars which would give you zoom.

      But frankly I highly doubt the result video is real, it lack vignetting and the focus is way too fast and narrow and precise.

      Still it has good advise like making a test version of paper and such, so it doesn’t matter that much.

  4. Mike,
    I love the cleanness of your metalwork. I’ve done things like this and but I would have made a Frankenstein’s metal monster version of this. I’m not much of a metalworker. I’m more of a utilitarian and would have had hose clamps and tie-wraps everywhere (LOL). However, I knew 1/4″ – 20 nut works as a great tripod fastener.

    I would like to suggest another project for your rig that I think you (and readers) will find interesting. It requires two of your rigs: If you mount, on your rig, a cheap 2-way laser communication system using a cheap red laser pointer (button locked on) and solar cell you can setup a very cool very private long-distance 2-way full-duplex (talk/listen at same time) audio system.

    To increase aiming they would also need a bicycle reflector mounted on the rig near (or around – drill large hole through it) binocular lens used for the solar cell. The solar cell would replace your camera. The laser pointer would not use either binocular lens as it is mounted on side of your rig and bore-sighted to a distant target.

    A cheap digital camera can be mounted on the OTHER binocular lens to help in laser aiming. The viewer could aim the tripod while watching for lasing of the distant rig station on his/her laptop. This will prevent personal eye damage from the laser too.

    I think that several LOS (line-of-sight) thousands of feet if not miles can be accomplished with this setup. If you need to find out how to build a cheap laser communicator Hack-A-Day has a few articles on that subject matter.

    Here is a conceptual model using your image of your rig:

  5. This sort of idea has a long history, going back at least to a German optical IR communicator that modulated a cunning prism/glass wedge assembly; however the Japanese, NEC I think, did a commercial light link in several models which had a telling detail – they used a parabolic reflector for the laser transmitter, but a fresnel lens for the receiver (both ~0.5m dia).

    For ranges greater than about 100m thermal cells in the air start to make the laser spot dance all over the place and a 1″ binocular lens becomes an impossibly small target to maintain.

    1. Yes Carl Zeiss Jena developed the Lichtsprechgerät 80 ( in the 1930’s based on Alexander Graham Bell’s 19th century light communication device called the Photo Phone. I did not know about the Japanese invention.

      None of the America-European versions during WW2 and post war used a LASER (per se). The laser was introduced after Dr. Ted Maiman (supposedly) perfected the solid state laser using ruby crystal at Hughes Aircraft (actually was already done in Germany during WW2 but kept top-secret).

      They used infrared ambient light. You are right that it works better than coherent light LASERS due to the scintillation effect which effects aiming. That’s why I mentioned using a bicycle reflector around the lens and keeping your maximum range down to a mile or less.

      Using a Fresnel Lens (senior-citizen’s magnifier lens? sheet) is the secret-ingredient that makes the ambient IR light source work so well over EXTREME ranges. It works for the IR transmitter LED and the IR receiver transistor. You’d have to use separate enclousres (boxes) to stop IR feedback.

      LASER’s introduce a little sci-fi flare and a aiming challenge which can be a little fun to do. Albeit, a real pain the arse if you depend on it for operational communications. Better suited to hobbyist mode.

      The extreme distances mentioned above have exceeded 100’s of miles from mountain top to mountain top. Google “modulated light” and look for Chris, VK3AML and Mike, VK7MJ web page which is down for some reason.

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