Improving Depth Of Field With Only 5 Phones

December 11, 2018 by 46 Comments

The hottest new trend in photography is manipulating Depth of Field, or DOF. It’s how you get those wonderful portraits with the subject in focus and the background ever so artfully blurred out. In years past, it was achieved with intelligent use of lenses and settings on an SLR film camera, but now, it’s all in the software.

The franken-camera rig, consisting of five Pixel 3 smartphones. The cameras are synchronised over WiFi.

For the Pixel 2 smartphone, Google had used some tricky phase-detection autofocus (PDAF) tricks to compute depth data in images, and used this to decide which parts of images to blur. Distant areas would be blurred more, while the subject in the foreground would be left sharp.

This was good, but for the Pixel 3, further development was in order. A 3D-printed phone case was developed to hold five phones in one giant brick. The idea was to take five photos of the same scene at the same time, from slightly different perspectives. This was then used to generate depth data which was fed into a neural network. This neural network was trained on how the individual photos relate to the real-world depth of the scene.

With a trained neural network, this could then be used to generate more realistic depth data from photos taken with a single camera. Now, machine learning is being used to help your phone decide which parts of an image to blur to make your beautiful subjects pop out from the background.

Comparison images show significant improvement of the “learned” depth data versus just the stereo-PDAF generated depth data. It’s yet another shot fired in the smartphone camera arms race, that shows no signs of abating. We just wonder when the Geiger counter mods are going to ship from factory.

[via AndroidPolice]

The Electronics Of Cold War Nightmares

November 27, 2018 by 8 Comments

It is a good bet that if you look around you, you’ll be able to find at least one smoke detector in sight. If not, there’s probably one not too far away. Why not? Fires happen and you’d like to know about a fire even if you are sleeping or alert others if you are away. During the cold war, there were other things that people didn’t want to sleep through. [Msylvain59] tears down two examples: a Soviet GSP-11 nerve agent detector and a Polish RS-70 radiation alarm. You can see both videos, below.

In all fairness, the GSP-11 is clearly not meant for consumer use. It actually uses a test strip that changes colors and monitors the color change. Presumably, the people operating it were wearing breathing gear because the machine could take quite a while to provide a positive output. Inside reminded us of a film processing machine, which isn’t too far off.

The radiation monitor looks more like a miniature version of an old floor-standing radio. The case design, the thick-traced, single-sided, hand-drawn printed wiring board, and the –by today’s standards — huge parts within all contribute to making this look like a piece of radio gear from the 1970s or even earlier.

Continue reading “The Electronics Of Cold War Nightmares” →

Junkbox Constant Current Source Helps With Kelvin Sensing

November 7, 2018 by 3 Comments

Is it ironic when a YouTube channel named “The Current Source” needs to build a current source? Or is that not ironic and actually just coincidental?

Regardless of linguistic considerations, [Derek], proprietor of the aforementioned channel has made and disassembled a few current sources in his day. Most of those jobs were for one-off precision measurements or even to drive a string of LEDs in what he describes as a pair of migraine-inducing glasses. Thankfully, The junk box current source presented in the video below is more in service of the former than the latter, as his goal is to measure very small resistances in semiconductors using Kelvin clips.

The current source uses a 24-volt switch-mode power supply and the popular LM317 adjustable voltage regulator. The ‘317 can be configured in a constant current mode by connecting the chip’s adjustment pin to the output through a series resistance. A multiturn pot provides current adjustment, although the logarithmic taper is not exactly optimal for the application. We spotted a pair of what appear to be optoisolators in the build too, but there’s no schematic and no discussion of what they do. [Derek] puts the final product to use for a Kelvin measurement of a 0.47-Ω 1% resistor at the end of the video.

We’re glad to see [Derek] in action; you may recall his earlier video about measuring his own radiation with a Geiger counter after treatment for thyroid cancer. Here’s hoping that’s behind him now.

Continue reading “Junkbox Constant Current Source Helps With Kelvin Sensing” →

I Hear You Offer WiFi

September 22, 2018 by 13 Comments

We are swimming in radio transmissions from all around, and if you live above the ground floor, they are coming at you from below as well. Humans do not have a sensory organ for recognizing radio signals, but we have lots of hardware which can make sense of it. The chances are good that you are looking at one such device right now. [Frank Swain] has leaped from merely accepting the omnipresent signals from WiFi routers and portable devices to listening in on them. The audio signals are mere soundwaves, so he is not listening to every tweet and email password, merely a representation of the data’s presence. There is a sample below the break, and it sounds like a Geiger counter playing PIN•BOT.

We experience only the most minuscule sliver of information coming at us at any given moment. Machines to hack that gap are not had to find on these pages so [Frank] is in good company. Magnetosensory is a popular choice for people with a poor sense of direction. Echolocation is perfect for fans of Daredevil. Delivering new sensations could be easier than ever with high-resolution tactile displays. Detect some rather intimate data with ‘SHE BON.’

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All The Badges Of DEF CON 26 (vol 4)

September 5, 2018 by 3 Comments

From a cockroach filled with LEDs, to an impressively dense 576 RGB LED display, and even a hunk of carpet, our final installment of the unofficial hardware badges at DEF CON 26 are beyond impressive. I tried to see every badge and speak to every badge maker this year. So far we’ve covered a ton of badges in volume 1, volume 2, and volume 3 of this series, and now it’s time to finish up!

If I didn’t get a chance to cover your badge in these articles, we still want to hear about it. What everyone wants is to dig into the details of these gorgeous examples of unique hardware. So post a project page for you badge on Hackaday.io, and make sure you get on the Conference Badges list that has been growing by leaps and bounds.

Continue reading “All The Badges Of DEF CON 26 (vol 4)” →

Friday Hack Chat: Environmental Sensors

September 5, 2018 by 3 Comments

When it comes to IoT and robotics, the name of the game is sensors. These aren’t just IMUs and the stuff that makes robots move — we’re talking about environmental sensors here. Everything from sensors that measure temperature, air quality, humidity, chemical sensors, and radiation sensors are on the table here. For this week’s Hack Chat, we’re talking all about environmental sensors with a hardware designer who has put them to the test.

Our guest for this week’s Hack Chat is Radu Motisan. He was a finalist in the 2014 Hackaday Prize with the uRad Monitor, a self-contained radiation monitoring network that sends radiation measurements out to a central server, that can be viewed by the entire world. The goal of this project is to create a worldwide network of radiation monitoring devices, and we’re going to say Radu has succeeded. There are hundreds of these uRad Monitors in over forty countries, and all of them are churning out data about the radiation environment in their neck of the woods.

By training, Radu is a software engineer with a masters in science. In his spare time, Radu plays around with chemistry, physics, and electronics. It’s this background that led Radu to create one of the most amazing Hackaday Prize projects ever.

We’ll kick off with a discussion of Radu’s uRad Monitor, and that means we’ll be covering:

  • Radiation Detection, why is it important, and what does it mean?
  • How do you detect radiation?
  • The differences between Geiger-Mueller tubes and scintillators

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Environmental Sensor Hack Chat Event Page and we’ll put that in the queue for the Hack Chat discussion.join-hack-chat

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, September 7th. Need a countdown timer? We should look into hosting these countdown timers on hackaday.io, actually.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

A Vacuum Tube And Barbecue Lighter X-Ray Generator

May 12, 2018 by 55 Comments

A certain subset of readers will remember a time when common knowledge held that sitting too close to the TV put you in mortal peril. We were warned to stay at least six feet back to avoid the X-rays supposedly pouring forth from the screen. Nobody but our moms believed it, so there we sat, transfixed and mere inches from the Radiation King, working on our tans as we caught up on the latest cartoons. We all grew up mostly OK, so it must have been a hoax.

Or was it? It turns out that getting X-rays from vacuum tubes is possible, at least if this barbecue lighter turned X-ray machine is legit. [GH] built it after playing with some 6J1 rectifier tubes and a 20-kV power supply yanked from an old TV, specifically to generate X-rays. It turned out that applying current between the filament and the plate made a Geiger counter click, so to simplify the build, the big power supply was replaced with the piezoelectric guts from a lighter. That worked too, but not for long — the tube was acting as a capacitor, storing up charge each time the trigger on the lighter was pulled, eventually discharging through and destroying the crystal. A high-voltage diode from a microwave oven in series with the crystal as a snubber fixed the problem, and now X-rays are as easy as lighting a grill.

We have to say we’re a wee bit skeptical here, and would love to see a video of a test. But the principle is sound, and if it works it’d be a great way to test all those homebrew Geiger counters we’ve featured, like this tiny battery-powered one, or this one based on the venerable 555 timer chip.