download porn 4kSchlieren imaging is a technique for viewing the density of transparent fluids using a camera and some clever optical setups. Density of a fluid like air might change based on the composition of the air itself with various gasses, or it may vary as a result of a sound or pressure wave. It might sound like you would need a complicated and/or expensive setup in order to view such things, but with a few common things you can have your own Schlieren setup as [elad] demonstrates.
download porn 4kHis setup relies on a cell phone, attached to a selfie stick, with a spherical mirror at the other end. The selfie stick makes adjusting the distance from the camera to the mirror easy, as a specific distance from the camera is required as a function of focal length. For cell phone cameras, it’s best to find this distance through experimentation using a small LED as the point source. Once it’s calibrated and working, a circular field of view is displayed on the phone which allows the viewer to see any change in density in front of the mirror.
The only downside of this build that [elad] notes is that the selfie stick isn’t stiff enough to prevent the image from shaking around a little bit, but all things considered this is an excellent project that shows a neat and useful trick in the photography/instrumentation world that could be useful for a lot of other projects. We’ve only seen Schlieren imaging once before and it used a slightly different method of viewing the changing densities.
Cameras are getting smarter and more capable than ever, able to run embedded machine vision algorithms and pull off tricks far beyond what something like a serial camera and microcontroller board would be capable of, and the upcoming Vizy aims to be even smarter and easier to use yet. Vizy is the work of Charmed Labs, and this isn’t their first foray into accessible machine vision. Charmed Labs are the same folks behind the Pixy and Pixy 2 cameras. Vizy’s main goal is to make object detection and classification easy, with thoughtful hardware features and a browser-based interface.
The usual way to do machine vision is to get a USB camera and run something like OpenCV on a desktop machine to handle the processing. But Vizy leverages a Raspberry Pi 4 to provide a tightly-integrated unit in a small package with a variety of ready-to-run applications. For example, the “Birdfeeder” application comes ready to take snapshots of and identify common species of bird, while also identifying party-crashers like squirrels.
The demonstration video on their page shows off using the built-in high-current I/O header to control a sprinkler, repelling non-bird intruders with a splash of water while uploading pictures and video clips. The hardware design also looks well thought out; not only is there a safe shutdown and low-power mode for the Raspberry Pi-based hardware, but the lens can be swapped and the camera unit itself even contains an electrically-switched IR filter.
[Nixie Guy] has hit all of important design elements in a single motorcycle helmet-cam project which packs in so much that the build log spans three posts. These cameras need to stand up to the elements and also to being pelted by insects at 80 MPH. They need to attach securely to the helmet without interfering with vision or movement of the head. And you should be able to adjust where they are pointing. The balance of features and cost available in consumer cameras make this list hard to satisfy — but with skills like these the bootstrapped camera came out great!
Where can you get a small, high quality camera? The drone industry has been iterating on this problem for a decade now and that’s where the guts of this creation come from. That produced an interesting issue, the board of the CADDX Turtle V2 camera gets really hot when in use and needs to have air flowing over it. So he threw a custom-milled heat sink into the side of the SLA resin printed housing to keep things somewhat cool.
Since the mill was already warmed up, why not do some mold making? Having already been working on a project to use a casting process for soft PCB membranes, this was the perfect technique to keep the buttons and the SD card slots weather tight on the helmet cam. A little pouch battery inside provides power, and the charging port on the back is a nice little magnet job.
Everything came together incredibly well. [Nixie Guy] does lament the color of the resin case, but that could be easily fixed by reprinting with colored resin.
The inspiration for this project came to him while he was working on his 1979 Merlin Pi Camera and found that setting the focus just right is vital in order to get good quality pictures. So he set himself the goal to build a mechanism that allows him to focus the camera precisely and remotely.
It is the plethora of LEGO-compatible parts that are available off-the-shelf that make such a project possible without the use of any 3D printed components. He not only found a LEGO-compatible continuous rotating servo but also a LEGO-compatible case for the Pi, and a LEGO cogwheel which almost fits exactly onto the camera lens. He also added a tripod mount to the case that allows him to set up the camera anywhere. The camera and focussing mechanism are controlled with a custom GUI based on guizero Python 3 library and the camera can be accessed remotely via?VNCViewer.
The Raspberry Pi HQ camera module is an exciting product that for the first time puts something close to a decent quality interchangeable lens camera into the hands of hardware hackers. It’s already attracted the attention of those who have a wish to explore the boundaries of camera form factors. Our latest entrant in this field comes courtesy of [?BBまどーし], who has opted for a very good 3D-printed analog of a conventional compact camera.
On the front as you might expect is the module, concealed behind a smart plastic ring. Behind that is a battery compartment, concealing not the brace of 18650s or the bare LiPo pouch that you might expect, but a 10,400 mAH USB power bank. Behind that is something approaching a conventional Raspberry Pi case, designed to take a Hyperpixel screen. The battery might seem an unadventurous choice, but it serves to highlight just how much bang for your buck can now be found in compact power banks. It may not have a hacker aesthetic, but you can’t argue with its cost and simplicity.
The details are the interesting part of this design, for instance it has a standard accessory shoe printed into its top. There is also a shutter button, but they admit to not being a software wizard enough to get it working. Perhaps a quick look at this Pi Camera in a 1970s Merlin game would be in order.
If you spent your youth watching James Bond or similar movies on rainy Saturday afternoons, then you may be familiar with a microdot as a top-secret piece of spy equipment, usually revealed as having been found attached to a seemingly innocuous possession of one of the bad guy’s henchmen, which when blown up on the screen delivers the cryptic yet vital clue to the location of the Evil Lair. Not something you give much thought in 2020 you might think, but that’s reckoning without [Sister HxA], who has worked out how to make them herself and detailed the process in a Twitter thread.
A microdot is a tiny scrap of photographic film, containing the image of some secret document or other, the idea being that it is small enough to conceal on something else. The example she gives is hiding it underneath a postage stamp. Because of their origins in clandestine work there is frustratingly little info on how to produce them, but she found a set of British instructions. Photographing a sheet such that its image occupies a small portion of her negative she makes a postage-stamp-sized one, and with care photographing that she manages to produce another of only a few millimetres in size. The smaller one isn’t very legible, but it’s still a fascinating process.
Before we forget — it’s cool; this one was already broken. The Merlin Pi camera’s wizardry works on two levels — [Mister M] can take still pictures and record video through the GUI he built for the touchscreen, or go retro and use the little push buttons nestled in the Merlin control panel. [Mister M] worked a Dropbox uploader into the GUI, so he doesn’t have to worry about filling up the SD card with backyard bird movies in the middle of filming them.
[Mister M] says he accidentally warped the Merlin’s battery cover while trying to soak away the sticker and had to use a piece of acrylic. Although it’s unfortunate, we think it may have been for the better given the huge hole necessitated by the camera lens. Check out the build video after the break.