Gigapixel Microscope Reveals Tiny Parts Of The Big Picture

[JBumstead] didn’t want an ordinary microscope. He wanted one that would show the big picture, and not just in a euphemistic sense, either. The problem though is one of resolution. The higher the resolution in an image — typically — the narrower the field of view given the same optics, which makes sense, right? The more you zoom in, the less area you can see. His solution was to create a microscope using a conventional camera and building a motion stage that would capture multiple high-resolution photographs. Then the multiple photos are stitched together into a single image. This allows his microscope to take a picture of a 90x60mm area with a resolution of about 15 μm. In theory, the resolution might be as good as 2 μm, but it is hard to measure the resolution accurately at that scale.

As an Arduino project, this isn’t that difficult. It’s akin to a plotter or an XY table for a 3D printer — just some stepper motors and linear motion hardware. However, the base needs to be very stable. We learned a lot about the optics side, though.

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Captivating ESP32 Camera Hack

You can never have enough DIY devices at home, so when you look at an ESP32 module that comes with the camera, you automatically start getting ideas. [Daniel Padilla] wanted a way to deploy DIY camera modules without the hassle of configuring them so he made one that looks like an access point and starts streaming as soon as you connect to it.[GitHub]

The code he provides allows the ESP32 to appear as an Open Access Point which you can connect to from a PC or smartphone. The awesome sauce here is that the ESP32 resolves all DNS requests to a redirect in a similar manner to what happens when someone connects to an open Wi-Fi access point in a mall, Instead of a captive portal page that asks the user to authenticate or accept terms and conditions, [Daniel Padilla]’s code instead redirects to the streaming page et voila! Instant camera stream, and it is that simple.

We love this project because it is an elegant way to solve a problem, and it also teaches newbies about captive portals and their implementation. We covered a cheap ESP32 Webcam in the past and this project also comes with code for you to get started. We would love to see what you come up with next.

Hunting Replicants With The 2019 LayerOne Badge

Blade Runner showed us a dystopian megatropolis vision of Los Angeles in the far-off future. What was a distant dream for the 1982 theater-goes (2019) is now our everyday. We know Los Angeles is not perpetually overcast, flying cars are not cruising those skies, and replicants are not hiding among the population. Or… are they?

The LayerOne conference takes place in greater Los Angeles and this year it adopted a Blade Runner theme in honor of that landmark film. My favorite part of the theme was the conference badge modeled after a Voight-Kampff machine. These were used in the film to distinguish replicants from humans, and that’s exactly what this badge does too. In the movies, replicants are tested by asking questions and monitoring their eyes for a reaction — this badge has an optional eye-recognition camera to deliver this effect. Let’s take a look!

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Flex PCB Saves Lens From The Junk Pile

There’s a piece of tech that many of us own, but very few of us have dissected. This is strange, given our community’s propensity for wielding the screwdriver, but how many of you have taken apart a camera lens. Even though many of us have a decent camera, almost none of us will have taken a lens to pieces because let’s face it, camera lenses are expensive!

[Anthony Kouttron] has taken that particular plunge though, because in cleaning his Olympus lens he tore its internal ribbon cable  from the camera connector to the PCB. Modern lenses are not merely optics in a metal tube, their autofocus systems are masterpieces of miniaturised electronics that penetrate the entire assembly.

In normal circumstances this would turn the lens from a valued photographic accessory into so much junk, but his solution was to take the bold path of re-creating the torn cable in KiCad and have it made as a flexible PCB, and to carefully solder  it back on to both connector and autofocus PCB. We applaud both the quality of his work, and thank him for the unusual glimpse into a modern lens system.

Lens repairs may be thin on the ground here, but we’ve had another in 2015 with this Nikon aperture fix.

A Very Modern Flying Spot Scanner

Analogue TV signals are a beautiful exercise in order and synchronisation, in that as the white dot on your old CRT TV back in the day traced its way across the glass it would have been doing so in faithful obedience to the corresponding electron beam in the camera at the studio. But a camera with a lens and light-sensitive scanning camera tube wouldn’t have been the only way of generating a picture. The flying-spot scanner drew a raster over its subject — usually celluloid film — with a white dot of light and recorded the result with a single photocell to produce a video signal. The ever resourceful [Niklas Roy] has built one using a video projector.

In this scanner the “dot” is a square of white pixels that is moved around the scene, while the sensor is a photoresistor that is read by an Arduino which passes the data to a PC. The whole is mounted in a booth that the subject positions themselves in front of, and covers their head with a cloth. It’s a slow process because the photoresistor is hardly the best sensor, in fact a portrait takes 83 seconds.

The result is hardly superlative quality, but of course this is an artwork in itself rather than a particularly good camera. It is however an impressive piece of work, and we know we’d give it a go if we had the chance.

[Niklas] is a frequent feature on these pages, having produces some pretty impressive work over the years. Some of our favourites are his container-sized music construction machine, and his tiny cardboard plotter.

An Easy Camera Slider Build

As smartphone cameras improve with each new generation, making quality video content is getting easier all the time. This means it takes a little more to stand out, so it pays to get creative with your cinematography. A slider is a great way to get some different shots, and you can build one pretty cheaply too (Youtube link, embedded below).

For smooth motion, [Nikodem Bartnik] used aluminium extrusion for the rails, along with some roller bearing wheels designed to suit. The wheels are built into a 3D printed carriage, which is also fitted with a spherical clamping camera mount. It’s all wrapped up with some socket head cap screws and 3D printed brackets to tie it all together.

Dimensional accuracy is key to the smooth operation of a slider, so you’ll want to have your printer set up well if you’re going to attempt this one. [Nikodem] demonstrates the slider is capable of taking the weight of an mid-range SLR with a tastefully sized lens, but if you’re going for something telephoto, you might want to go for something bigger. You could also consider a motorized rig instead. Video after the break.

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Camera Sees Electromagnetic Interference Using An SDR And Machine Vision

It’s one thing to know that your device is leaking electromagnetic interference (EMI), but if you really want to solve the problem, it might be helpful to know where the emissions are coming from. This heat-mapping EMI probe will answer that question, with style. It uses a webcam to record an EMI probe and the overlay a heat map of the interference on the image itself.

Regular readers will note that the hardware end of [Charles Grassin]’s EMI mapper bears a strong resemblance to the EMC probe made from semi-rigid coax we featured recently. Built as a cheap DIY substitute for an expensive off-the-shelf probe set for electromagnetic testing, the probe was super simple: just a semi-rigid coax jumper with one SMA plug lopped off and the raw end looped back and soldered. Connected to an SDR dongle, the probe proved useful for tracking down noisy circuits.

[Charles]’ project takes that a step further by adding a camera that looks down upon the device under test. OpenCV is used to track the probe, which is moved over the DUT manually with the help of an augmented reality display that helps track coverage, with a Python script recording its position and the RF power measurements. The video below shows the capture process and what the data looks like when reassembled as an overlay on top of the device.

Even if EMC testing isn’t your thing, this one seems like a lot of fun for the curious. [Charles] has kindly made the sources available on GitHub, so this is a great project to just knock out quickly and start mapping.

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