Simple Photo Enlarger Makes Great Addition To Any Darkroom

April 26, 2022 by Lewin Day 6 Comments

Chemical-based photography can seem like a dark art at times, but it needn’t be so. [Dan K] developed the Simple Enlarger to help spread the idea that classical photographic darkroom tools are fundamentally quite easy to understand and build.

A photographic enlarger illuminates a negative with light, and focuses this light on a sheet of photographic paper which can then be developed. [Dan’s] enlarger design is intended to be built using materials readily available from any dollar store or stationer’s shop, and can be built in just a few short hours. It’s built to work with a single film format and with a fixed size of photographic paper for simplicity’s sake.

A simple M-mount camera lens is pressed into service for the main optic, with the ex-Soviet part chosen for its easy focusing and cheap price. A small plywood box makes a decent body, and a white phosphor LED provides the light source. The final rig is designed to print 35mm negatives on to standard 8×10 paper.

If you want to get into developing your own negatives and don’t want to buy a commercial enlarger, [Dan]’s build could be just the way to go. We’ve seen some other similar builds before, too. Meanwhile, if you’ve got your own nifty darkroom hacks, be sure to drop us a line!

What Exactly Is A Gaussian Blur?

July 21, 2021 by Lewin Day 29 Comments

Blurring is a commonly used visual effect when digitally editing photos and videos. One of the most common blurs used in these fields is the Gaussian blur. You may have used this tool thousands of times without ever giving it greater thought. After all, it does a nice job and does indeed make things blurrier.

Of course, we often like to dig deeper here at Hackaday, so here’s our crash course on what’s going on when you run a Gaussian blur operation. Continue reading “What Exactly Is A Gaussian Blur?” →

Hello, Holograms

December 24, 2020 by Brian McEvoy 8 Comments

Holograms are tricky to describe because science-fiction gives the name to any three-dimensional image. The science-fact versions are not as flashy, but they are still darn cool. Legitimate holograms are images stored on a photographic medium, and they retain a picture of the subject from certain angles. In other words, when [Justin Atkin] makes a hologram of a model building, (video, embedded below) you can see the east side of the belfry, but when you reorient, you see the west side, or the roof if you point down. Holography is different from stereoscopy, which shows you a 3D image using two cameras. With a stereoscopic image, you cannot tilt it and see a new part of the subject, so there is a niche for each method.

There are a couple of different methods for making a hologram at home. First, you probably want a DIY hologram kit since it will come with the exposure plate and a known-good light source. Far be it for us to tell you you can’t buy plates and a laser pointer to take the path less traveled. Next, you need something that will not move, so we’re afraid you cannot immortalize your rambunctious kitty. The last necessity is a stable platform since you will perform a long-exposure shot, and even breathing on the setup can ruin the image. Different colors come from the coherent light source, so getting the “Rainbow Holograms” advertised in the video is a matter of mixing lights. Since you can buy red, green, and blue laser pointers for a pittance, you can do color remixes to your content.

Another type of hologram appears on things like trading cards as those wildly off-color (chromatic, not distasteful) images of super-heroes or abstract shapes. They’re a different variety, which can be printed en-masse, unlike the one-off [Justin] shows us how to make.

If you’re yearning for volumetric displays, we are happy to point you to this beauty capable of showing a jaw-dropping 3D model or this full-color blocky duck.

Continue reading “Hello, Holograms” →

A Soap Film Photography How-To

March 16, 2019 by Lewin Day 8 Comments

Blowing bubbles is a pastime enjoyed by young and old alike. The pleasant motion and swirling colors of the bubbles can be remarkably relaxing. With the right tools and techniques, it’s possible to take striking photos of these soap film phenomena, and that’s exactly what [Eric] and [Travis] did.

Adding sugar to the soap solution increases the resilience of the film significantly. With enough added, the film no longer pops, but instead breaks and fails in interesting ways.

After beginning with a robotic arm and a computer fan blowing bubbles, the project moved towards a simple stepper motor setup. A thin frame is lowered into a solution of soapy water, then brought back up by the stepper motor. The resulting soap film is held in front of a black background and carefully lit with a softbox light.

Lens selection is critical for this sort of work – in this case, a TS-E 50mm Macro f/2.8 lens was the order of the day. [Eric] shares other tips for taking great shots, such as adding sugar to the solution to make the soap film last longer, and using a modified speaker to help “paint” the surface of the films.

The resulting images are beautiful examples of the art, showing vibrant colors from the interference patterns created by the light. [Eric] has done a great job of clearly documenting the development process and the final results, making it possible for others to recreate the project elsewhere.

We’ve seen other soapy projects before, like this automatic bubble blowing machine. Video after the break.

Continue reading “A Soap Film Photography How-To” →

10,000-Year-Old Camera Lens Takes Striking Pictures

October 25, 2018 by Bryan Cockfield 46 Comments

The first photograph was taken sometime in the early 1800s, and through almost two centuries of development we’ve advanced through black-and-white, the video camera, and even high-speed cameras that can take thousands of frames per second. [Mathieu Stern] took a step back from all of the technological progress of the past two hundred years, though, and found a lens for his camera hidden in the glacial ice of Iceland.

Ice in this part of the world has been purified over the course of 10,000 years, and [Mathieu] realized that with this purity the ice could be formed into a workable camera lens. The first step was to get something that could actually form the ice into the proper shape, and for that he used a modified ice ball maker that was shaped to make a lens rather than a sphere. Next, he needed an enclosure to hold the lens and attach it to his camera, which he made using a 3D printer.

For this build, the hardest part probably wasn’t making the actual equipment, but rather getting to the right place in Iceland and actually making the lenses. At room temperature the lenses could be made in around five minutes, but in Iceland it took almost 45 minutes and the first four attempts broke. The fifth one was a charm though, so after over five hours on the beach he was finally able to make some striking images with the 10,000-year-old ice lens which melted after only a minute of use. If that seems like too much work, though, you can always outfit your camera with no lens at all.

Thanks to [baldpower] for the tip!

Continue reading “10,000-Year-Old Camera Lens Takes Striking Pictures” →

Smile For The Raspberry Pi Powered Photo Booth

June 5, 2015 by Rick Osgood 5 Comments

[Roo] was tasked with finding a better way to take corporate employee photos. The standard method was for a human resources employee to use a point and shoot camera to take a photo of the new recruits. The problem with this method is many people feel awkward trying to force a smile in front of other people. Plus, if the photo turns out poorly many people won’t ask to have it retaken so as not to feel vain or inconvenience the photographer. [Roo’s] Raspberry Pi powered photo booth solves this problem in a novel way.

The new system has the employee use their own mobile phone to connect to a website running on the Pi. When the employee tells the Pi to snap a photo, the system uses the Raspberry Pi camera module to capture an image. [Roo] actually 3D printed a custom adapter allowing him to replace the standard camera lens if desired. The photo can be displayed on an LCD screen so the user can re-take the photo if they wish.

The system is built into a custom case made from both 3D printed and laser cut parts. The front plate is a frosted white color. [Roo] placed bright white lights behind the front panel in order to act as a flash. The frosted plastic diffuses the light just enough to provide a soft white light for each photo taken. Once the photo is selected, it can then be uploaded to the company database for use with emails, badges, or whatever else.

[Roo] also mentions that the system can easily be changed to send photos via Twitter or other web applications. With that in mind, this system could be a great addition to any hackerspace or event. The code for an older version of the project can be found on the project’s github page.

Continue reading “Smile For The Raspberry Pi Powered Photo Booth” →

Pictures That Defeat Key Locks

May 23, 2015 by Mike Szczys 65 Comments

We’re at LayerOne this weekend and one of the talks we were excited about didn’t disappoint. [Jos Weyers] presented Showing Keys in Public — What Could Possibly Go Wrong? The premise is that pictures of keys, in most cases, are as good as the keys themselves. And that pictures of keys keep getting published.

[Jos] spoke a bit about new services that offer things like 3D scanning and storage of your key for printing when you get locked out, or apps that ask you to take a picture of your key and they’ll mail you a duplicate. Obviously this isn’t the best of ideas; you’re giving away your passwords. And finding a locksmith is easier than findind a 3D printer. But it’s the media gaffs with important keys that intrigues us.

We’ve already seen the proof of concept for taking covert images to perfectly duplicate a key. But these examples are not so covert. One example is a police officer carrying around handcuff keys on a belt clip. Pose for a picture and that key design is now available to all. But news stories about compromised keys are the biggest offenders.

A master key for the NYC Subway was compromised and available for sale. The news coverage not only shows a picture at the top of the story of a man holding up the key straight on, but this image of it on a subway map which can be used to determine scale. This key, which is still published openly on the news story linked above, opens 468 doors to the subway system and these are more than just the ones that get you onto the platform for free. We were unable to determine if these locks have been changed, but the sheer number of them has us thinking that it’s unlikely.

Worse, was the availability of fire-department ~~master~~ keys ~~which open lock boxes outside of every building~~. (Correction: these are fire department keys but not the actual lock-box keys) A locksmith used to cut the original keys went out of business and sold off all their stock. These keys were being sold for $150, which is bad enough. But the news coverage showed each key on a white background, straight on, with annotations of where each type of key will work.

Other examples include video news stories about credit card skimmers installed in gas pumps — that coverage showed the key used to open the pump housing. There was also an example of speed camera control cabinet keys being shown by a reporter.

[Jos’] example of doing the right thing is to use a “prop” key for news stories. Here he is posing with a key after the talk. Unfortunately this is my own house key, but I’m the one taking pictures and I have blurred the teeth for my own security. However, I was shocked during image editing at the quality of the outline in the image — taken at 6000×4000 with no intent to make something that would serve as a source for a copy. It still came out remarkably clear.