Laser Brings Autofocus To Tricked-Out Large Format Film Camera

You can’t argue with the results of large-format film cameras — picture the boxy bellows held by a cigar-chomping big-city press photographer of the 1940s — but they don’t really hold a candle to the usability and portability of even the earliest generations of 35mm cameras. And add in the ease-of-use features of later film and digital cameras, and something like a 4×5 Graflex seems like a real dinosaur.

Or maybe not. [Aleksi Koski] has built a large-format camera with autofocus, the “Conflict 45.” The problem with a lot of the large-format film cameras, which tend to be of a non-reflex optical design, is that it’s difficult or even impossible to see what you’re shooting through the lens. This makes focusing a bit of a guessing game, a problem that [Aleksi] addresses with his design. Sadly, the linked Petapixel article is basically devoid of technical details, but from what we can glean from it and the video below, the Conflict 45 is a 4″x5″ sheet-film camera that has a motorized lens board and a laser rangefinder. A short video has a through-viewfinder view showing an LCD overlay, which means there’s some kind of microcontroller on board as well, which is probably used for the calculations needed to compensate for parallax errors during close focusing, as well as other uses.

The camera is built from 3D printed parts; [Aleksi] says that this is just a prototype and that the finished camera will have a carbon-fiber body. We’d love to see more build details, but for now, we just love the idea of an easy-to-use large-format camera. Just maybe not that big.

Continue reading “Laser Brings Autofocus To Tricked-Out Large Format Film Camera”

The Apollo Digital Ranging System: More Than Meets The Eye

If you haven’t seen [Ken Shirriff]’s teardowns and reverse engineering expeditions, then you’re in for a treat. His explanation and demonstration of the Apollo digital ranging system is a fascinating read, even if vintage computing and engineering aren’t part of your normal fare.

The average Hackaday reader should be familiar with the concept of determining the distance of a faraway object by measuring how long it takes a sound or radio wave to be reflected, such as in sonar and radar. Going another step and measuring Doppler Shift – the difference in the returned signal’s frequency – will tell us the velocity of the object relative to our position. It’s so simple that an Arduino can do it. But in the days of Apollo, there was no Arduino. In fact, there were no Integrated Circuits. And Apollo missions went all the way to the moon- far too distant for relatively simple Radar measurements. Continue reading “The Apollo Digital Ranging System: More Than Meets The Eye”

Laser Rangefinder Brought To Life With Arduino

Range finders are amazing tools for doing pretty much anything involving distance calculations. Want to blink some lights when people are nearby? There’s a rangefinder for that. Need to tell how far away the next peak of a mountain range is? There’s a rangefinder for that. But if you’re new to range finders and want one that’s hackable and configurable, look no further than the SF02/F rangefinder with the Arduino shield, and [Laser Developer]’s dive into what this pair can do.

Once the rangefinder and shield have been paired is when the magic really starts to happen. Using USB, the Arduino can instantly report a huge amount of raw data coming from the rangefinder. From there, [Laser Developer] shows us how to put the device into a “settings” mode which expands the capabilities of the rangefinder even more. The data can be dumped into a graph, for example, which can show trends between distance, laser strength, and many other data sets. [Laser Developer] goes one step further and demonstrates how to use this to calculate the speed of light, but from there pretty much anything else is possible as well.

And while you can just buy a rangefinder off the shelf, they are fairly limiting in their features and can cost exponentially more. This is a great start into using a tool like this, especially if you need specific data or have a unique application. But, if laser range finding isn’t for you or if this project is too expensive, maybe this $5 ultrasonic rangefinder will work better for your application.

THP Entry: A Repurposed Luminiferous Aether Detector

laserIn the late 1800s, no one knew what light was. Everyone knew it behaved like a wave some of the time, but all waves need to travel through some propagation medium. This propagation medium was called the luminiferous aether and an attempt to detect and quantify this aether led to one of the coolest experimental setups of all time: the Michelson-Morely experiment. It was a huge interferometer mounted on a gigantic slab of marble floating in a pool of mercury. By rotating the interferometer, Michelson and Morely expected to see a small phase shift in the interferometer, both confirming the existence of a luminiferous aether and giving them how fast the Earth moved through this medium.

Of course, there was no phase shift, throwing physics into chaos for a few years. When [Beaglebreath] first learned about the Michelson-Morely interferometer he was amazed by the experimental setup. He’s built a few interferometers over the years, but for The Hackaday Prize, he’s making something useful out of one of these luminiferous aether detectors: a functional laser rangefinder capable of measuring distances of up to 60 inches with an error of 0.000005 inches.

The core of the system is an HP 5528A laser interferometer system. [Beaglebreath] has been collecting the individual components of this system off of eBay for several years now, and amazingly, he has all the parts. That’s dedication, right there. This laser interferometer system will be mounted to a simple camera slider, and with the interferometer measurements, humidity and temperature measurements, and some interesting code (running on one of these for hacker cred), [Beaglebreath] stands a good shot at measuring things very, very accurately.

The devil is in the details, and when you’re measuring things this precisely there are a lot of details. The original Michelson-Morely interferometer was affected by passing horse-drawn carriages and even distant lightning storms. While [Beaglebreath] isn’t using as long of a beam path as the OG interferometer, he’ll still have a lot of bugs to squash to bring this project to its full potential.

SpaceWrencherThe project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

Bike Alert Tells Drivers To Back Off

Bicycle commuters are often in a battle with drivers for space on the road. [Hammock Boy] does all of his commuting on two human-powered wheels, and is quite interested in not getting hit by a car. He decided to ply his hobby skills to build a device that helps keep him safe. It’s not just a tail light, it’s a sensor that shines brighter the closer a car is to the back of the bike.

The sensor portion is the ultrasonic range finder seen in the center of the protoboard. Surrounding it is a set of LEDs. Each is individually addressable with the whole package controlled by an Arduino. The sketch measures the distance between the back of the bike and whatever’s behind it. If there’s nothing, one Red led is illuminated. If there is an object, the lights shine brighter, and in different patterns as the distance decreases.

Certainly the next iteration could use a standalone chip without the need for the whole Arduino. This could even work with two battery cells and no voltage regulator. We also think the use of any other color than Red LEDs is suspect but we do love the concept.

Arduino Hits The Battlefield — For Real

We’re not sure if this is the first time, but here’s some pretty solid proof that Arduino has found its way into the weapons of war. The creators, [Derek Wales], [John Eischer], and [George Hopkins] are all Electronics Engineering majors at West Point. They came up with this idea after seeing video footage of a firefight in Afghanistan where combat soldiers were calling in artillery strikes using a compasses and GPS devices. It’s an all-in-one unit that can provide the same information quickly and accurately. The prototype above, which they call the DemonEye, contains a laser range finder, digital compass, and a GPS module. The article also states that it contains a mini-computer but we recognize that as an Arduino Mega (thanks to Miguel over at Areopago 21 for noticing this first and sending in the tip about it).

The prototype apparently comes in at $1000. Okay, it seems a bit high but not out of the ballpark. What we can’t understand is how the second generation of devices was billed out at $100,000 for five more units. What’s the going rate for laying out military-grade PCBs?

RF Range Finder Doesn’t Need To See To Calculate Distance


Instructables user [Jones Electric] has been quite busy lately, building a radio-frequency range finder. Built as part of a German youth science competition, he and his partner built a pair of transmitter/receiver modules that can be used to measure distances of up to a mile (~1.5km). Their argument for radio-based rangefinders is that laser rangefinders are obviously limited to line of sight, whereas their range finders are not.

To determine the distance between the two stations, the base station is triggered, which starts a counter and sends a 433 MHz signal to the second station. When the second station receives the signal, it in turn broadcasts an 868 MHz signal, which is received by the base station. The total distance between the points is then calculated based upon the round trip time of the two radio signals.

[Jones Electric] claims that the range finder is relatively accurate, with a deviation of up to 5 meters per measurement, and that the accuracy could be increased by adding a higher frequency crystal to the timing circuit.

We are pretty sure using these two frequencies in the US without a license is not allowed, though we are unsure of the usage laws in Germany, where this was constructed.