Interesting Optical Journey Results In Hybrid Viewfinder For Smartphones

Fair warning: if you ever thought there was nothing particularly interesting with optical viewfinders, prepare to have your misconception corrected by [volzo] with this deep-dive into camera-aiming aids that leads to an interesting hybrid smartphone viewfinder.

For most of us, the traditional optical viewfinder is very much a thing of the past, having been supplanted by digital cameras and LCD displays. But some people still want to frame a photograph the old-fashioned way, and the optical principles that make that possible are actually a lot more complicated than they seem. [volzo]’s blog post and video go into a great deal of detail on viewfinder optics, so feel free to fall down that rabbit hole — it’s worth the trip. But if you’d rather cut to the chase, the actual viewfinder build starts at about the 23:00 mark in the video.

The design is an interesting combination of lenses and beamsplitters that live in a 3D-printed enclosure. The whole thing slips over one end of a smartphone and combines an optical view of the scene that corresponds to the camera’s field of view with a small digital overlay from the phone’s screen. The overlay is quite simple: just some framing gridlines and a tilt indicator that’s generated by a little Android app. But it’s clear that much more information could be added now that [volzo] has all the optical issues sorted out.

We appreciate this deep dive into something that appears to be mundane and outdated, which actually proves to be non-obvious and pretty interesting. And if you have any doubt about the extreme cleverness of the camera engineers of yore, look no further than this sort-of solar-powered camera from the 1960s.

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Rocket Mounted 3D Printed Camera Wheel Tries, Succeeds, And Also Fails

[Joe] at BPS.space has a thing for rockets, and his latest quest is to build a rocket that will cross the Kármán Line and launch into the Final Frontier. And being the owner of a YouTube channel, he wants to have excellent on-board video that he can share. The trouble? Spinning. A spinning rocket is a stable rocket, especially as altitude increases. So how would [Joe] get stable video from a rocket spinning at several hundred degrees per second? That’s the question being addressed in the video below the break.

The de-spun video looks quite good

Rather than use processing power to stabilize video digitally, [Joe] decided to take a different approach: Cancelling out the spin with a motor, essentially making a camera-wielding reaction wheel that would stay oriented in one direction, no matter how fast the rocket itself is spinning.

Did it work? Yes… and no. The design was intended to be a proof of concept, and in that sense there was a lot of success and some excellent video was taken. But as with many proof of concept prototypes, the spinning camera module has a lot of room for improvement. [Joe] goes into some details about the changes he’ll be making for revision 2, including a different motor and some software improvements. We certainly look forward to seeing the progress!

To get a better idea of the problem that [Joe] is trying to solve, check out this 360 degree rocket cam that we featured a few years ago.

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Bring Out The Fine Detail In Small Objects With This Coaxial Lighting Rig

All things considered, modern photography is pretty easy. It’s really just a matter of pointing the camera at the thing you want to take a picture of and letting the camera do the rest. But that doesn’t mean good photographs are easy to make, especially when fine detail is required. And that’s the reason this 3D printed coaxial lighting setup was built — to make quality photographs of small objects a snap.

The objects of [Peter Lin]’s photographic desire are coins, no doubt of the collectible variety. Since the condition of a coin is essential to determining its value, numismatic photographers really need to be meticulous about the quality of their work. The idea here is to keep the incoming light parallel to the optical axis of the camera, for which purpose ring lights around the camera lens are often used. But they can result in lighting artifacts, and can be awkward to use for such smaller subjects.

So for this setup, [Peter] essentially built a beam-splitter. The body is a printed block that’s painted matte black to keep reflections down; a little self-adhesive flocking paper helps with that too. The round aperture on the top is for the camera lens, with the square window on the side admitting light. The secret is a slot oriented at 45 degrees to both of those openings, into which the glass element from a cheap UV filter is inserted. The filter acts like a beam splitter which reflects light down onto the coin on the bottom of the block and lets it pass up into the camera lens directly above the coin, parallel to the optical axis. Genius!

The video below shows it in use with both DSLR and smartphone cameras, and the image quality is amazing. While most of us probably aren’t photographing coins, we do enough high-resolution photography of small objects that this seems applicable. In a way, it reminds us of [Big Clive]’s “TupperCam” method of high-res PCB photography (final item).

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Taking (Good) Pictures Of PCBs

Snapping pictures is not technically difficult with modern technology, but taking good photographs is another matter. There are a number of things that a photographer needs to account for in order to get the best possible results, and if the subject matter isn’t particularly photogenic to start with it makes the task just a little more difficult. As anyone who’s posted something for sale online can attest, taking pictures of everyday objects can present its own challenges even to seasoned photographers. [Martijn Braam] has a few tricks up his sleeve for pictures like this in his efforts to photograph various circuit boards.

[Martijn] has been updating the images on Hackerboards, an online image reference for single-board computers and other PCBs, and he demands quality in his uploads. To get good pictures of the PCBs, he starts with ample lighting in the form of two wirelessly-controlled flashes in softboxes. He’s also using a high quality macro lens with low distortion, but the real work goes into making sure the image is sharp and the PCBs have well-defined edges. He’s using a Python script to take two pictures with his camera, and some automation in ImageMagic to composite the two images together.

While we’re not all taking pictures of PCBs, it’s a great way of demonstrating the ways that a workflow can be automated in surprising ways, not to mention the proper ways of lighting a photography subject. There are some other excellent ways of lighting subjects that we’ve seen, too, including using broken LCD monitors, or you can take some of these principles to your workspace with this arch lighting system.

Telnet Gets Stubborn Sony Camera Under Control

According to [Venn Stone], technical producer over at LinuxGameCast, the Sony a5000 is still a solid option for those looking to shoot 1080p video despite being released back in 2014. But while the camera is lightweight and affordable, it does have some annoying quirks — namely an overlay on the HDMI output (as seen in the image above) that can’t be turned off using the camera’s normal configuration menu. But as it so happens, using some open source tools and the venerable telnet, you can actually log into the camera’s operating system and fiddle with its settings directly.

As explained in the write-up, the first step is to install Sony-PMCA-RE, a cross-platform suite of tools developed for reverse engineering and modifying Sony cameras. With the camera connected via USB, this will allow you to install a program on the camera called Open Memories Tweak. This unlocks some developer options on the camera, such as spawning a telnet server on its WiFi interface.

With the a5000 connected to your wireless network, you point your telnet client to its IP address and will be greeted by a BusyBox interface that should be familiar to anyone who’s played with embedded Linux gadgets. The final step is to invoke the proper command, bk.elf w 0x01070a47 00, which sets the specific address of the camera’s configuration file to zero. This permanently disables the HDMI overlay, though it can be reversed by running the command again and setting the byte back to 01.

As you might expect, the Sony-PMCA-RE package is capable of quite a bit more than just unlocking a telnet server. While it might not be as powerful as a firmware modification such as Magic Lantern for Canon’s hardware, those looking for a hackable camera that won’t break the bank might want to check out the project’s documentation to see what else is possible.

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A slide carousel with a DSLR attached to its lens output

Digitize Your Slide Deck With This Arduino-Powered Slide Carousel

If you’re above a certain age, you probably remember the atmosphere of a pre-Powerpoint 35 mm slide show. The wobbly screen being unrolled, the darkened room, the soft hum of the projector’s fan, the slightly grainy picture on the screen and that unmistakable click-whoosh-clack sound as the projector loaded the next slide. Nowadays you’ll be hard pressed to find anyone willing to set up a screen and darken the room just to watch a few photos, so if you still have any slides lying around you’ll probably want to digitize them. If you’ve also kept your projector then this doesn’t even have to be that difficult, as [Scott Lawrence] shows in his latest project.

[Scott] made a setup to directly connect a DLSR, in this case a Nikon D70, to a Kodak 760 slide carousel. The attachment is made through a 3D-printed adapter that fits onto the Nikon’s macro lens on one side and slides snugly into the carousel’s lens slot on the other. The adapter also holds an IR transmitter which is aimed at the camera’s receiver, in order to trigger its remote shutter release function.

The carousel’s original light source was replaced with a compact LED studio light, which allows for precise brightness control and of course remains nice and cool compared to the original incandescent bulb. The light, camera and carousel motor are all controlled through a central user interface driven by an Arduino Leonardo which can automatically advance the carousel and instruct the camera to take a picture, thereby taking the hard work out of digitizing huge stacks of slides.

[Scott] plans to make the software and STL files available on GitHub soon, so anyone can go ahead and turn their projector into a digitizer. If you’ve misplaced your projector however, a simple 3D-printed slide adapter for your camera also works for small slide decks.

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Automatic Lens Cover Helps Cameras Cover Space Launches

Shooting space launches often requires the use of remote cameras for safety reasons. However, that means there’s no photographer on hand to wipe lenses down if they happen to get condensation from the prevailing weather conditions. [Michael Baylor] was having issues with atmospheric moisture interfering with his launch shots, so built a custom automatic lens cap to help solve the issue. 

The design is simple, consisting of a large shutter that pivots to cover the camera lens when photos aren’t being taken, controlled by an impressively-beefy servo. Not only does the automatic cap protect the lens from condensation prior to the moment of launch, it also closes to cover the lens as the rocket leaves the frame. This protects the lens from all the dust and debris flying its way, kicked up by the rocket exhaust on takeoff.

[Michael] found that the lens cap easily outperformed his usual anti-condensation solution. While his camera with the auto-cap shot mostly-clean pics, another camera fitted with 18-hour handwarmers suffered significantly from condensation. The plan is to add just a little heat to the auto-cap setup to stave off condensation for good, even when shooting at pads like Vandenburg, California.

Details on the build are slim, but the basic concept is all there. Throw together a servo with some 3D-printed components and a microcontroller and you can build a setup custom-tailored to your own rig and use case. If you find yourself needing a capable long-range camera remote, too, we’ve seen those before as well! Video after the break.

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