All You Need To Know About Photographic Lenses

If you have ever played around with lenses, you’ll know that a convex lens can focus an image onto a target. It can be as simple as focusing the sun with a magnifying glass to burn a hole in a piece of paper, but to achieve the highest quality images in a camera there is a huge amount of optical engineering and physics at play to counteract the imperfections of those simple lenses.

Many of us in the hardware world aren’t optical specialists but our work frequently involves camera modules, so [Matt Williams]’ piece for PetaPixel laying out a primer on lens design should be essential reading well beyond its target audience of photographers.

In it we learn how a photographic lens is assembled from a series of individual lenses referred to as elements, combined together in groups to lend the required properties to the final assembly. We are introduced to the characteristics of different types of glass, and to the use of lens coatings to control reflections. Then we see examples of real lens systems, from some famous designs with their roots in the 19th century, to the lenses of today.

Sometimes a piece written for an entirely different audience can bring really useful insights into our field, and this is one of those times. We learned something, and we think you will too.


Header image: 4300streetcar, CC BY 4.0.

Bento Is An All-In-One Computer Designed To Be Useful

All-in-one computers in which the mainboard lurked beneath a keyboard were once the default in home computing, but more recently they have been relegated to interesting niche devices such as the Raspberry Pi 400 and 500.

The Bento is another take on the idea, coming at it not with the aim of replacing a desktop machine, instead as a computer for use with wearable display glasses. The thinking goes that when your display is head mounted, why carry around a screen with your laptop.

On top it’s a keyboard, but underneath it’s a compartmentalized space similar to the Japanese lunchboxes which lend the project its name. The computing power comes courtesy of a Steam Deck so it has a USB-C-for-everything approach to plugging in a desktop, though there’s a stated goal to produce versions for other boards such as the Raspberry Pi. There’s even an empty compartment for storage of peripherals.

We like this computer, both for being a cyberdeck and for being without a screen so not quite like the other cyberdecks. It’s polished enough that we could almost imagine it as a commercial product. It’s certainly not the first Steam Deck based cyberdeck we’ve seen.

Game Boy? NES? Why Not Both!

If you’re a retro Nintendo fan you can of course carry a NES and a Game Boy around with you, but the former isn’t very portable. Never fear though, because here’s [Chad Burrow], who’s created a neat handheld console that emulates both.

It’s called the Acolyte Handheld, and it sports the slightly unusual choice for these parts of a PIC32 as its main processor. Unexpectedly it can use Sega Genesis controllers, but it has the usual buttons on board for portable use. It can drive either its own LCD or an external VGA monitor, and in a particularly nice touch, it switches between the two seamlessly. The NES emulator is his own work, while Game Boy support comes courtesy of Peanut-GB.

We like the design of the case, and particularly that of the buttons. Could it have been made smaller by forgoing some of the through-hole parts in favour of SMD ones? Quite likely, but though it’s chunky it’s certainly not outsized.

Portable Nintendo-inspired hardware is popular around here, as you can see with this previous handheld NES

ESP32 Dashboard Is A Great Way To Stay Informed

The original ESP32 may be a little long in the tooth by now, but it remains a potent tool for connected devices. We were drawn to [Max Pflaum]’s ESP32 Dashboard as a great example, it’s an ESP32 hooked up to an e-paper display. The hardware is simple enough, but the software is what makes it interesting.

This is deigned as a configurable notification tool, so to make it bend to the user’s will a series of widgets can be loaded onto it. The device runs MicroPython, making it easy enough to write more than the ones already on place. The screen is divided into four zones, allowing for a range of widgets to be used at once. All the details can be found in a GitHub repository.

We like it for its configurability and ease of programming, and because it delivers well on the promise of a useful device. An ESP32 and e-ink combination with MicroPython apps is something we’ve seen before in the world of badges.

Capturing Screenshots Using A Fake Printer

If you have very old pieces of analogue test equipment with CRTs on your bench, the chances are they will all have surprisingly similar surrounds to their screens. Back when they were made it was common to record oscilloscope screens with a Polaroid camera, that would have a front fitting for just this purpose.

More recent instruments are computerized so taking a screen shot should be easier, but that’s still not easy if the machine can’t save to a handy disk. Along comes [Tom] with a solution, to hook up a fake printer, and grab the screen from a print.

Old instruments come with a variety of ports, serial, IEE-488, or parallel, but they should usually have the ability to print a screen. Then capturing that is a case of capturing an interpreting the print data, be it ESC/P, PCL5, Postscript, or whatever. The linked page takes us through a variety of techniques, and should be of help to anyone who’s picked up a bargain in the flea market.

This isn’t the only time we’ve touched on the subject of bringing older computerized equipment into the present, we’ve also shown you a disk drive emulator.

Thanks [JohnU] for the tip.

The PCB Router You Wish You Had Made

The advent of cheap and accessible one-off PCB production has been one of the pivotal moments for electronic experimenters during the last couple of decades. Perhaps a few still etch their own boards, but many hobbiest were happy to put away their ferric chloride. There’s another way to make PCBs, though, which is to mill them. [Tom Nixon] has made a small CNC mill for that purpose, and it’s rather beautiful.

In operation it’s a conventional XYZ mechanism, with a belt drive for the X and Y and a lead screw for the Z axis. The frame is made from aluminium extrusion, and the incidental parts such as the belt tensioners are 3D printed. The write-up is very comprehensive, and takes the reader through all the stages of construction. The brains of the outfit is a Creality 3D printer controller, but he acknowledges that it’s not the best for the job.

It’s certainly not the first PCB router we’ve seen, but it may be one of the nicer ones. If you make a PCB this way, you might like to give it professional-looking solder mask with a laser.

Taking A One Handed Keyboard To The Next Level

When a wrist mounted keyboard floated past in the Hackaday feed, a mental image surfaced, perhaps something like a Blackberry keyboard mounted on a wrist cuff, maybe with some kind of display. It’s impressive indeed then to open the link and see [AdamLeBlanc]’s Schist01. It’s a wrist mounted keyboard, but with its bracket curving in front of the had to support a custom ergonomic chording keyboard, it’s definitely a break from the norm.

The wrist mount has clearly taken a lot of thought, and despite looking something like the arm of a Star Trek Borg, appears comfortable. It’s extremely adjustable, and can be demounted into several different parts. Meanwhile the keyboard itself has been formed to his hand by a trial and error process involving keycaps and a clay model. there’s even a thumb-operable touchpad.

We like this peripheral a lot, for the huge attention to detail that has gone into its design, for its boldness, and because we can’t help seeing ourselves using it as the input device for a futuristic head-mounted display. For now though we don’t have any futuristic silver clothing in the wardrobe, so that will have to wait. If you’d like to see more, there’s a video.

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