Image Sensor From Discrete Parts Delivers Glorious 1-Kilopixel Images

December 30, 2019 by Dan Maloney 35 Comments

Chances are pretty good that you have at least one digital image sensor somewhere close to you at this moment, likely within arm’s reach. The ubiquity of digital cameras is due to how cheap these sensors have become, and how easy they are to integrate into all sorts of devices. So why in the world would someone want to build an image sensor from discrete parts that’s 12,000 times worse than the average smartphone camera? Because, why not?

[Sean Hodgins] originally started this project as a digital pinhole camera, which is why it was called “digiObscura.” The idea was to build a 32×32 array of photosensors and focus light on it using only a pinhole, but that proved optically difficult as the small aperture greatly reduced the amount of light striking the array. The sensor, though, is where the interesting stuff is. [Sean] soldered 1,024 ALS-PT19 surface-mount phototransistors to the custom PCB along with two 32-bit analog multiplexers. The multiplexers are driven by a microcontroller to select each pixel in turn, one row and one column at a time. It takes a full five seconds to scan the array, so taking a picture hearkens back to the long exposures common in the early days of photography. And sure, it’s only a 1-kilopixel image, but it works.

[Sean] has had this project cooking for a while – in fact, the multiplexers he used for the camera came up as a separate project back in 2018. We’re glad to see that he got the rest built, even with the recycled lens he used. One wonders how a 3D-printed lens would work in front of that sensor.

Continue reading “Image Sensor From Discrete Parts Delivers Glorious 1-Kilopixel Images” →

Robot Vs. Superbug

November 30, 2019 by Bryan Cockfield 6 Comments

Working in a university or research laboratory on interesting, complicated problems in the sciences has a romanticized, glorified position in our culture. While the end results are certainly worth celebrating, often the process of new scientific discovery is underwhelming, if not outright tedious. That’s especially true in biology and chemistry, where scaling up sample sizes isn’t easy without a lot of human labor. A research group from Reading University was able to modify a 3D printer to take some of that labor out of the equation, though.

This 3D printer was used essentially as a base, with the printing head removed and replaced with a Raspberry Pi camera. The printer X/Y axes move the camera around to all of the different sample stored in the print bed, which allows the computer attached to the printer to do most of the work that a normal human would have had to do. This allows them to scale up massively and cheaply, presumably with less tedious inputs from a large number of graduate students.

While the group hopes that this method will have wide applicability for any research group handling large samples, their specific area of interest involves researching “superbugs” or microbes which have developed antibiotic resistance. Their recently-published paper states that any field which involves bacterial motility, colony growth, microtitre plates or microfluidic devices could benefit from this 3D printer modification.

Object Tracking Camera Slider Gets The Nice Shots

November 24, 2019 by Lewin Day 1 Comment

In this day and age, where all leisure activities must be duly captured and monetized online, camera sliders are hot items. Many start with a simple manual build, before graduating to something motorized for more flexibility. [Saral Tayal] took things a step further, implementing a basic tracking mode for even sweeter shots.

The build is mechanically simple, relying on 8mm steel rods and linear bearings more typically found in 3D printers. An Arduino Uno is pressed into service to run the show, outfitted with an OLED screen to run the interface. A RoboClaw motor controller is used to control the geared DC motors used, one controlling the linear motion, the other the rotation of the camera.

With encoders fitted to the motors, the RoboClaw controller enables the Arduino to track the position and rotation of the slider as it moves. The slider then can be given the position of an object relative to itself. With a little maths, it will rotate the camera to track the object as it moves along.

It’s a simple addition to the typical slider build that greatly increases the variety of shots that can be achieved. There are plenty of ways to go about building a slider, too, as we’ve seen before. Video after the break.
Continue reading “Object Tracking Camera Slider Gets The Nice Shots” →

DIY Photo Backup In The Field

November 20, 2019 by Bryan Cockfield 29 Comments

They say a file isn’t backed up if it isn’t backed up twice. This is easy enough to do if you have access to your computer and a network, but if you’re a photographer you might end up in a place without either of these things and need a way to back up the files you just created. For that you’ll need a specialized photo backup tool which you can easily build yourself.

While commercial offerings are available which back up files locally from a camera’s SD card to another medium, they suffer from a high price. [André]’s solution can be had for a fraction of that cost. Using a Raspberry Pi Zero, a tiny USB hub, and a high capacity jump drive, a photographer can simply plug in an SD card and the Pi will handle the backups with varying levels of automation. The software that [André] made use of is called Little Backup Box written by [Dmitri Popov] and can be used typically as an automatic backup for any other device as well.

This is a great solution to backing up files on the go, whether they’re from a camera or any device that uses an SD card. Removable storage is tiny and easily lost, so it’s good to have a few backups in case the inevitable happens. Raspberry Pis are an ideal solution to data backup, and can even be battery powered if you’re really roughing it for a few days.

Open Source Kitchen Helps You Watch What You Eat

November 20, 2019 by Gerrit Coetzee 6 Comments

Every appliance business wants to be the one that invents the patented, license-able, and profitable standard that all the other companies have to use. Open Source Kitchen wants to beat them to it.

Every beginning standard needs a test case, and OSK’s is a simple one. A bowl that tracks what you eat. While a simple concept, the way in which the data is shared, tracked, logged, and communicated is the real goal.

The current demo uses a Nvidia Jetson Nano as its processing center. This $100 US board packs a bit of a punch in its weight class. It processes the video from a camera held above the bowl of fruit, suspended by a scale in a squirrel shaped hangar, determining the calories in and calories out.

It’s an interesting idea. One wonders how the IoT boom might have played out if there had been a widespread standard ready to go before people started walling their gardens.

A Mechanical Shutter Release For A Digital Camera

November 18, 2019 by Lewin Day 19 Comments

Most digital cameras these days come with some kind of electronic remote shutter release. Various solutions exist, using USB cables, smartphone apps, or dedicated remotes. [Steloherd] wasn’t happy with the options available for his Ricoh GRII, though, so built a rig to do things the old fashioned way.

The spring plate helps protect the shutter button from damage.

[Steloherd] wanted to use an old-school mechanical release cable, so devised a way to use it to trigger the Ricoh’s standard shutter button. A small aluminium bracket was created, attached to the hot shoe on top of the camera via a mounting foot from a standard flash accessory. A spring plate was then created to help spread the load from the mechanical release pin, ensuring it triggers the camera effectively without damaging anything.

Installing the mechanical release proved difficult, as the DIN standard calls for an obscure M3.4 conical tapped thread. Rather than muck about finding rare tooling, [Steloherd] simply recut the thread on the release cable to a straight M3x0.5, and did the same for the bracket.

Overall, it’s a tidy hack, and one that could be adapted to other cameras fairly easily. Other methods we’ve seen involve such odd choices as linear actuators harvested from air fresheners, if you’d believe it. As always, if it works, it works!

Quick And Dirty Digital Conversion For Analog SLR

November 14, 2019 by Lewin Day 37 Comments

The unarguable benefits of digital photography has rendered the analog SLR obsolete for most purposes. This means that a wide selection of cameras and lenses are available on the second hand market for pennies on the dollar, making them ripe targets for hacking. [drtonis] decided to experiment with a quick and easy digital conversion to an old Canon A-1, and it’s got us excited about the possibilities.

Who needs Instagram filters? Just distort in-camera!

It’s a simple hack, but a fun one. The SLR is opened up, and the spring plate for holding the film is removed. A Raspberry Pi camera then has its original lens removed, and is placed inside the film compartment. It’s held in with electrical tape, upon a 3mm shim to space it correctly to work with the original optics.

[drtonis] notes that the build isn’t perfect, with some aberration likely caused by the reflective electrical tape in the film cavity. However, we think it’s a nice proof of concept that could go so much further. A Raspberry Pi Zero could be easily squeezed inside along with the camera, and everything glued in place to make things more robust. A specialist paint such as Stuart Semple’s Black 2.0 could also help cut down on light leaks inside. Plus, there’s plenty of small screens that can be used with the Raspberry Pi that would provide a useful preview function.

We’d love to see more conversions like this one. While it’s unlikely they’ll compete with commercial DSLRs on outright performance, everyone loves a little bit of charming distortion here and there, and all manner of fancy lenses can be had for cheap for analog platforms. We’ll be keeping a close eye on the tipline for further This fundevelopments – you know what to do!

Continue reading “Quick And Dirty Digital Conversion For Analog SLR” →