Everything You Always Wanted To Know About Radioactive Lenses

We think of radioactive material as something buried away in bunkers with bombs, power plants, and maybe some exotic medical equipment. But turns out, there are little bits of radiation in the water, our soil, bananas, granite countertops, smoke detectors, and even some camera lenses. Camera lenses? A few decades ago, camera companies added rare elements like thorium to their glass to change the optical properties in desirable ways. The downside? Well, it made the lenses somewhat radioactive.  A post by [lenslegend] explains it all.

Exotic elements such as Thorium, Lanthanum and Zirconium are added to glass mixtures to create the high refractive indexes necessary in sophisticated lens designs. Selection of premium quantities of glass from the large glass pots, stringent spectrophotometric tests after stress and strain checks provide the valuable raw glass for ultimate use in lens elements.
Konica Hexanon Lens Guide, Konica Camera Company, 1972

According to [lenslegend] the practice started in 1945 with Kodak. However, by the 1980s, consumer distaste for radioactive things and concern for factory workers ended the production of hot camera lenses.

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Raspberry Pi Crammed Into Old Film Camera

If you wanted an expensive film camera when you were a kid, you are in luck. Used film SLRs are super cheap now that everyone wants digital cameras. Of course, in reality, you want a digital camera, too. So do what [befinitiv] did. Make a film cartridge out of a Raspberry Pi that can convert your camera to digital. (Video, embedded below.)

In theory, this sounds like a genius idea. The practical aspect isn’t perfect, though. For one thing, the small image sensor used means that the camera is zoomed in quite a bit. Also, the shutter button isn’t integrated, so the shutter is open all the time. You may think that doesn’t matter, but don’t forget that the way an SLR works means if the shutter is open, there’s no viewfinder.

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Scanning Medium Format Film On A 35mm Scanner

Scanning film is great for archival purposes as well as sharing said photos digitally. However, if you’re scanning 120 film, aka medium format, it can be expensive to get the requisite hardware. 35mm scanners are comparatively more common, so [Christian Chapman] decided to modify one to suit medium film instead.

The hack is for the Plustek 8100, and requires modifying the scanner in two ways. Firstly, the driver has to be scanned to sweep a longer range to take into account the bigger film. Secondly, a part of the film carriage has to be replaced so it doesn’t show up in the scanners field of view.

The former is achieved by using the sane-genesys scanner software backend, which can be easily modified to adjust the scan length values appropriately. The latter is achieved via 3D printing replacement components that fit without blocking the requisite area.

It’s a tidy hack and one that allows [Christian] to both scan medium format film as well as overscan 35mm film to capture details from the sprocket hole area. We’ve seen fully custom film scanner builds before, too. If you’ve built your own scanner, be sure to drop us a line!

Hands-On Review: TCam-Mini WiFi Thermal Imager

A thermal camera is a tool I have been wanting to add to my workbench for quite a while, so when I learned about the tCam-Mini, a wireless thermal camera by Dan Julio, I placed an order. A thermal imager is a camera whose images represent temperatures, making it easy to see things like hot and cold spots, or read the temperature of any point within the camera’s view. The main (and most expensive) component of the tCam-Mini is the Lepton 3.5 sensor, which sits in a socket in the middle of the board. The sensor is sold separately, but the campaign made it available as an add-on.

Want to see how evenly a 3D printer’s heat bed is warming up, or check whether a hot plate is actually reflowing PCBs at the optimal temperature? How about just seeing how weird your pets would look if you had heat vision instead of normal eyes? A thermal imager like the tCam-mini is the tool for that, but it’s important to understand exactly how the tCam-mini works. While it may look like a webcam, it does not work like one.

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Analog Camera Goes Digital

The digital camera revolution swept through the world in the early 2000s, and aside from some unique situations and a handful of artists still using film, almost everyone has switched over to digital since then. Unfortunately that means that there’s a lot of high quality film cameras in the world that are gathering dust, but with a few pieces of equipment it’s possible to convert them to digital and get some more use out of them.

[befinitiv]’s latest project handles this conversion by swapping in a Raspberry Pi Zero where the film cartridge would otherwise be inserted into the camera. The Pi is attached to a 3D-printed case which mimics the shape of the film, and also houses a Pi camera right in front of the location where the film would be exposed. By removing the Pi camera’s lens, this new setup is able to take advantage of the analog camera’s optics instead and is able to capture images of relatively decent quality.

There are some perks of using this setup as well, namely that video can be broadcast to this phone over a wireless connection to a computer via the Raspberry Pi. It’s a pretty interesting build with excellent results for a remarkably low price tag, and it would be pretty straightforward to interface the camera’s shutter and other control dials into the Raspberry Pi to further replicate the action of an old film camera. And, if you enjoy [befinitiv]’s projects of bringing old tech into the modern world, be sure to check out his 80s-era DOS laptop which is able to run a modern Linux installation.

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Lego Microscope Aims To Discover Future Scientists

When it comes to inspiring a lifelong appreciation of science, few experiences are as powerful as that first glimpse of the world swimming in a drop of pond water as seen through a decent microscope. But sadly, access to a microscope is hardly universal, denying that life-changing view of the world to far too many people.

There have been plenty of attempts to fix this problem before, but we’re intrigued to see Legos used to build a usable microscope, primarily for STEM outreach. It’s the subject of a scholarly paper (preprint) by [Bart E. Vos], [Emil Betz Blesa], and [Timo Betz]. The build almost exclusively uses Lego parts — pretty common ones at that — and there’s a complete list of the parts needed, which can either be sourced from online suppliers, who will kit up the parts for you, or by digging through the old Lego bin. Even the illuminator is a stock part, although you’ll likely want to replace the orange LED buried within with a white one. The only major non-Lego parts are the lenses, which can either be sourced online or, for the high-power objective, pulled from an old iPhone camera. The really slick part is the build instructions (PDF), which are formatted exactly like the manual from any Lego kit, making the build process easily accessible to anyone who has built Lego before.

As for results, they’re really not bad. Images of typical samples, like salt crystal, red onion cells, and water fleas are remarkably clear and detailed. It might no be a lab-grade Lego microscope, but it looks like it’s more than up to its intended use.

Thanks for the heads up on this, [Jef].

Cocktail Of Chemicals Makes This Blueprint Camera Unique

When you’re looking at blueprints today, chances are pretty good that what you’re seeing is anything but blue. Most building plans, diagrams of civil engineering projects, and even design documents for consumer products never even make it to paper, let alone get rendered in old-fashioned blue-and-white like large-format prints used to produced. And we think that’s a bit of a shame.

Luckily, [Brian Haidet] longs for those days as well, so much so that he built this large-format cyanotype camera to create photographs the old-fashioned way. Naturally, this is one of those projects where expectations must be properly scaled before starting; after all, there’s a reason we don’t go around taking pictures with paper soaked in a brew of toxic chemicals. Undaunted by the chemistry, [Brian] began his journey with simple contact prints, with Sharpie-marked transparency film masking the photosensitive paper, made from potassium ferricyanide, ammonium dichromate, and ammonium iron (III) oxalate, from the UV rays of the sun. The reaction creates the deep, rich pigment Prussian Blue, contrasting nicely with the white paper once the unexposed solution is washed away.

[Brian] wanted to go beyond simple contact prints, though, and the ridiculously large camera seen in the video below is the result. It’s just a more-or-less-lightproof box with a lens on one end and a sheet of sensitized paper at the other. The effective ISO of the “film” is incredibly slow, leading to problematically long exposure times. Coupled with the distortion caused by the lens, the images are — well, let’s just say unique. They’ve got a ghostly quality for sure, and there’s a lot to be said for that Prussian Blue color.

We’ve seen cyanotype chemistry used with UV lasers before, and large-format cameras using the collodion process. And we wonder if [Brian]’s long-exposure process might be better suited to solargraphy.

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