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Stereo Microscope = 2 Video Cameras + Raspberry Pi(S) + Phone + Google Cardboard Headset?

Trash80toHP_Mini

NIGHT STALKER
I've been wanting a stereo microscope for soldering for the longest time, but no funds available for such a luxury and no place to store one.

Has anyone seen such a stereoscope bodge? If not, it's time for the Raspberry Pi gang here to knit the parts together I think. Stereo photography has been an on and off obsession of mine and I had the camera/viewer drawer out last night. Google Cardboard VR setup sitting on the shelf hit me like a brick this morning. Stereo Reality done with such a setup in real time might work well enough as a Poor Man's Stereo Microscope? I see the printed camera setup clearly and suitable lenses/cameras ought to be easy enough to find.

Here are a couple of headsets for under $10.

Google-Cardboard-RPi-Stereo-001.JPG

Google-Cardboard-RPi-Stereo-000.JPG

I'm thinking that using a headset that's not mechanically connected to the optics should be a lot easier on my neck than using the real deal. [:)]

I see the components clearly, but the Raspberry Pi to stereo video feed (over Bluetooth?) for the Smartphone magic is hazy and well outside my skill set.

 

davidg5678

Well-known member
Neat idea!

I think there a few challenges to overcome in order to get this to work. The trickiest one is latency. Part of what makes using a real microscope great is that there is not any delay between moving your hand and seeing it move. Transmitting video data usually adds a delay of a few milliseconds, especially if it is wireless and high resolution. Maybe with some wires and very fast (or no) video processing, an acceptable latency could be achieved.

The other thing to figure out is optics. I think it is possible to purchase stand alone microscope objectives and other lenses online relatively cheaply. You'd want a reasonable working distance, the ability to focus, and maybe even adjustable zoom.

It might be tricky to figure out how to create something like this, but I bet that it could be done if someone were determined enough to build it. I'm not sure how cost competitive it would end up being with ~$300 stereoscopes available from Ali Express, but I'm sure it would be fun!

 

Trash80toHP_Mini

NIGHT STALKER
Thanks, hoping someone has seen one developed to snatch some refined research/ideas though. Hadn't realized that the real thing had hit such low price levels.

Moving in slow motion ought to help with the latency issue?

Connecting via Lightning Cable was my first notion?

As you said, this might be pointless, but here goes with initial research:

Original concept:

Optics should be easy enough to come by. I'd avoid the complication of getting a pair of zoom lenses synchronized. Fixed Focal lengths would be less expensive and setting them hard up against closest focus simplifies matters greatly. Mounting the a lens of suitable focal length backwards makes for a decent enough macro lens. Reversing my 90mm Elmarit with its lens shade taped to a bellows worked great for me.

Google-Cardboard-RPi-Stereo-003.JPG

https://www.seeedstudio.com/10MP-25mm-C-Mount-Lens-for-Raspberry-Pi-High-Quality-Camera-p-4622.html

This one's a lot more expensive than I'd like but it gets the idea across. Such an inexpensive portrait length C-Mount lens mounted backwards or even forwards could do. Normal or Telephoto might work better, dunno, but someone might.

Google-Cardboard-RPi-Stereo-002.JPG

https://www.thingiverse.com/thing:3004414

Love the printed extension ring concept, a pair could be mounted to or integrated into the printed binocular holder.

Google-Cardboard-RPi-Stereo-008.JPG

I was inspired by the C-Mount, Interchangeable Lens - Raspberry Pi HQ Camera with 12MP Sensor, but that gets too close to the Ali Express pricing. Got linkage to one of their suitable offerings?

Bargain Basement Bodge approach:

Google-Cardboard-RPi-Stereo-004.JPG

4 Pieces 5 Megapixels 1080p Sensor OV5647 Mini Camera $16.99

Standoffs beat retail C-Mount pricing and a quartet of cheap cameras set up for extreme closeup and a bit wider angle views would be good. Unfortunately these appear to be for stills. 720p @ 60FPS video costs twice as much, 1080p @ 30FPS might be good enough?

Google-Cardboard-RPi-Stereo-007.JPG

DORHEA Raspberry Pi Mini Camera Video Module 5 - $8.19

Assuming "fixed focus" means non-zoom fixed focal length? If the lens can be unscrewed and mounted in reverse using a printed setup based on the printed C-Mount extension tube setup, this might be a way to keep the cost at rock bottom? Not figuring in the Pi costs here, could a pair of Zeros work?

Haven't mentioned the LED ringlight setup yet, but that'd be necessary. Thinking LED mounting points would be integrated into each printed extension tube, bodged to power source for the Pi(s) and cost should be negligible?

More middling price range:

The real deal from the source seems to have higher frame rates in a more expensive alternative. The lens "looks" better, but focus tab could be a very minor problem for the printed, reversed extension tube notion though.

Google-Cardboard-RPi-Stereo-009.JPG

Raspberry Pi Camera Module V2-8 Megapixel,1080p (RPI-CAM-V2) - $23.97

Scissors or dykes would shorten that up to a more workable length right quick. [}:)]

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Stumbled across a great, unrelated, but fabulous project. Love the prototyping setup.

Google-Cardboard-RPi-Stereo-005.JPG

Project OWL Open Source Hardware Ophthalmoscope is 25 Times Cheaper than Commercial Products

 
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