Hyperspectral Imaging – Seeing The Unseeable

October 25, 2017 by Will Sweatman 25 Comments

They say that a picture is worth a thousand words. But what is a picture exactly? One definition would be a perfect reflection of what we see, like one taken with a basic camera. Our view of the natural world is constrained to a bandwidth of 400 to 700 nanometers within the electromagnetic spectrum, so our cameras produce images within this same bandwidth.

For example, if I take a picture of a yellow flower with my phone, the image will look just about how I saw it with my own eyes. But what if we could see the flower from a different part of the electromagnetic spectrum? What if we could see less than 400 nm or greater than 700 nm? A bee, like many other insects, can see in the ultraviolet part of the spectrum which occupies the area below 400 nm. This “yellow” flower looks drastically different to us versus a bee.

In this article, we’re going to explore how images can be produced to show spectral information outside of our limited visual capacity, and take a look at the multi-spectral cameras used to make them. We’ll find that while it may be true that an image is worth a thousand words, it is also true that an image taken with a hyperspectral camera can be worth hundreds of thousands, if not millions, of useful data points. Continue reading “Hyperspectral Imaging – Seeing The Unseeable” →

Interference Scanner With Clear Instructions

October 25, 2017 by Brian McEvoy 13 Comments

Meticulous. Thorough. Exacting. These are all words we’d use to describe this video by [BrendaEM] about her Homemade 3D Optical Interference Scanner which can be seen after the break. The scanner uses 3D-printed parts and repurposed materials you might find lying around in your spare parts bin. An old optical drive tray acts to move the laser-wielding sled while a stripped-out webcam is an optical sensor. Links to relevant files such as 3D models and Arduino sketches will be found in the video’s author section.

The principle of operation is demonstrated with a water analog in the video at 2:00 with waves in a plastic container. By creating two small apertures between a light source and a sensor, it’s possible to measure the light waves which make it through. [BrendaEM] uses some powerful visualization software to convert her samples into 3D models which look really cool and simultaneously demonstrate the wave nature of light.

On the left side of her device are the control electronics which don’t need any special coatings since light won’t pass over this area. For the right side, where coherent light is measured, to borrow a Rolling Stones lyric: no colors anymore, I want them to turn black. Even the brass strips with apertures are chemically darkened.

Most of the laser hacks here use lasers rather than measure them, like this Laser Clock and a Laser Projector.

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Giving A 4k Webcam Special Eyes

September 23, 2017 by Dan Maloney 4 Comments

It’s a problem as old as photography: your camera is only as good as your lens. As cameras shrink, so do lenses, and so do the options for upgrading to a better lens. And forget about switching to a different focal length or aperture — it’s often just not an option. Unless you make it an option by adding a CS lens mount to a high-end webcam.

We’ll stipulate that at 4k resolution and packed with all sorts of goodies, the Logitech Brio Pro is a heck of a nice camera. And the lens isn’t bad either, as you’d hope for a camera with almost 9 megapixels at its disposal. But with an optical field of view optimized for video conferencing, it’s hard to use this premium camera for much else. [Saulius] fixed that by taking the camera apart and adding a new case with a built-in C- and CS-mount, resulting in literally thousands of lens choices. [Saulius]’ post has valuable teardown information, which includes exposing the CCD sensor completely. The new case is sold as a kit, but it looks like a 3D-printed case would be pretty easy to whip up.

[Salius] sure seems to love those optical hacks, whether they be a budget microscope camera, high-resolution LIDAR, or capturing license plates at great distances.

Take A Time-Lapse Or Bake A Cake With This Kitchen Timer Panning Rig

September 17, 2017 by Dan Maloney 22 Comments

Seems like the first thing the new GoPro owner wants to do is a time-lapse sequence. And with good reason – time-lapses are cool. But they can be a bit bland without a little camera motion, like that provided by a dirt-cheap all-mechanical panning rig.

Let’s hope [JackmanWorks]’ time-lapse shots are under an hour, since he based his build on a simple wind-up kitchen timer, the likes of which can be had for a buck or two at just about any store. The timer’s guts were liberated from the case and a simple wooden disc base with a 1/4″-20 threaded insert for a tripod screw was added. The knob, wisely left intact so the amount of time left in the shot is evident, has a matching bolt for the camera’s tripod socket. Set up the shot, wind up the timer, and let it rip at 1/60 of an RPM. Some sample time-lapse shots are in the video below.

Turning this into a super-simple powered slider for dollying during a time-lapse wouldn’t be too tough — if you’ve already got a nice pantograph slide rig built.

Continue reading “Take A Time-Lapse Or Bake A Cake With This Kitchen Timer Panning Rig” →

Low-Vision Reading Through A Camera’s Eye

September 13, 2017 by Kristina Panos 13 Comments

Borescope cameras are great inspection tools. They’re flexible, they magnify on a variable scale, and they come with their own lighting. Oh, and they’re pretty cheap, too. Because of all this, these tiny cameras can serve a number of purposes. Doctors put them down your cake hole to look for ulcers and polyps, and mechanics probe pistons with them to check for buildup. [agulesin] used one to make a reading aid for his mom.

Mom suffers from macular degeneration, and can’t read print smaller than 1″ (2.5cm). This condition can cause issues ranging from blurred vision to complete loss of vision in the center of the visual field. Standard handheld magnifiers can work fairly well depending on a person’s condition, but they only provide a fixed magnification level and most offer no lighting.

[Agulesin] had the idea to make a reading magnifier by feeding video from a downward-facing borescope camera to an old netbook. The camera is mounted in a plywood arm that’s fixed to a bi-level platform made from scrap MDF. It’s a simple idea that’s well executed—just project flat, printed material on to a vertical screen. There’s nothing for the user to hold or mount, and no risk of neck strain from looking down over the material.

With any simple project comes limitations. The camera is fixed in place. This rig built to view sheets of A4 paper (between letter and legal size) that are moved around by the user, and it can only handle a stack of so many sheets. If [agulesin]’s mom tried to read a thick novel this way, the camera would likely not focus. Even so, it’s a great piece of assistive tech for people with low vision.

A Compact, Portable Pantograph Camera Slider

September 1, 2017 by Dan Maloney 14 Comments

Ho, hum, another camera slider, right? Wrong — here’s a camera slider with a literal twist.

What sets [Schijvenaars]’ slider apart from the pack is that it’s not a slider, at least not in the usual sense. A slider is a mechanical contrivance that allows a camera to pan smoothly during a shot. Given that the object is to get a camera from point A to point B as smoothly as possible, and that sliders are often used for long exposures or time-lapse shots, the natural foundation for them is a ball-bearing linear slide, often powered by a stepper motor on a lead screw. [Schijvenaars] wanted his slider to be more compact and therefore more portable, so he designed and 3D-printed a 3-axis pantograph mechanism. The video below shows the slider panning the camera through a silky smooth 60 centimeters; a bonus of the arrangement is that it can transition from panning in one direction to the other without any jerking. Try that with a linear slider.

Granted, this slider is not powered, but given that the axes are synced with timing belts, it wouldn’t be difficult to add a motor. We’ve seen a lot of sliders before, from simple wooden units to complicated overhead cranes, but this one seems like a great design with a lot of possibilities.

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Stunning Fake Polaroid Camera Performs Magic

August 31, 2017 by Anool Mahidharia 39 Comments

It’s high time us Muggles got our hands on the hardware used to take Magical Photographs as seen in The Daily Prophet. The first pioneering step in that direction has been taken by [Abhishek] who built this moving picture taking polaroid-ish camera, which he’s calling the “Instagif NextStep”. It’s a camera that records a short, three second video, converts it to GIF and ejects a little cartridge which displays the animated photo.

This amazing piece of hardware has been painstakingly built, and the finished product looks great. The nice thing about building such projects, in [Abhishek]’s own words, is that “it involves a bunch of different skill sets and disciplines – hardware, software, 3D modeling, 3D printing, circuit design, mechanical/electrical engineering, design, fabrication etc that need to be integrated for it to work seamlessly.”
Continue reading “Stunning Fake Polaroid Camera Performs Magic” →