Film photography began with a mercury-silver amalgam, and ended with strips of nitrocellulose, silver iodide, and dyes. Along the way, there were some very odd chemistries going on in the world of photography, from ferric and silver salts to the prussian blue found in Cyanotypes and blueprints.
Metal salts are fun, and for his Hackaday Prize entry, [David Brown] is building a printer for these alternative photographic processes. It’s not a dark room — it’s a laser printer designed to reproduce images with weird, strange chemistries.
Cyanotypes are made by applying potassium ferricyanide and ferric ammonium citrate to some sort of medium, usually paper or cloth. This is then exposed via UV light (i.e. the sun), and whatever isn’t exposed is washed off. Instead of the sun, [David] is using a common UV laser diode to expose his photographs. he already has the mechanics of this printer designed, and he should be able to reach his goal of 750 dpi resolution and 8-bit monochrome.
Digital photography will never go away, but there will always be a few people experimenting with light sensitive chemicals. We haven’t seen many people experiment with these strange alternative photographic processes, and anything that gets these really cool prints out into the world is great news for us.
The sensor on your digital camera picks up a lot more than just the light that’s visible to the human eye. Camera manufacturers go out of their way to reduce this to just the visible spectrum in order to produce photos that look right to us. But, what if you want your camera to take photos of the full light spectrum? This is particularly useful for astrophotography, where infrared light dramatically adds to the effect.
Generally, accomplishing this is just a matter of removing the internal IR-blocking filter from your camera. However, most of us are a little squeamish about tearing into our expensive DSLRs. This was the dilemma that [Gavin] faced until a couple of years ago when he discovered the Canon EOS-M.
Now, it’s important to point out that one could do a similar conversion with just about any cheap digital camera and save themselves a lot of money (the practically give those things away now). But, as any photography enthusiast knows, lenses are just as important as the camera itself (maybe even more so).
So, if you’re interested in taking nice pictures, you’ve got to have a camera with an interchangeable lens. Of course, if you’re already into photography, you probably already have a DSLR with some lenses. This was the case for [Gavin], and so he needed a cheap digital camera that used Canon interchangeable lenses like the ones he already had. After finding the EOS-M, the teardown and IR-blocking filter removal was straightforward with just a couple of hiccups.
When [Gavin] wrote his post in 2014, the EOS-M was about $350. Now you can buy them for less than $150 used, so a conversion like this is definitely into the “cheap enough to tinker” realm. Have a Nikon camera? The Nikon 1 J3 is roughly equivalent to the original EOS-M, and is about the same price. Want to save even more money, and aren’t concerned with fancy lenses? You can do a full-spectrum camera build with a Raspberry Pi, with the added benefit of being able to adjust what light is let in.
[Maurice] is a photographer specializing in micrographs. These very large images of very small things are beautiful, but late last year he’s been limited by his equipment. He needed a new microscope, one designed for photography, that had a scanning stage, and ideally one that was cheap. He ended up choosing a microscope from the 80s. Did it meet all his qualifications? No, but it was good enough, and like all good tools, capable of being modified to make a better tool.
This was a Nikon microscope, and [Maurice] shoots a Canon. This, of course, meant the camera mount was incompatible with a Canon 5D MK III, but with a little bit of milling and drilling, this problem could be overcome.
That left [Maurice] with a rather large project on his hands. He had a microscope that met all his qualifications save for one: he wanted a scanning stage, or a bunch of motors and a camera controller that could scan over a specimen and shoot gigapixel images. This was easily accomplished with a few 3D printed parts, stepper motors, and a Makeblock Orion, an Arduino-based board designed for robotics that also has two stepper motor drivers.
With a microscope that could automatically scan over a specimen and snap a picture, the only thing left to build was a piece of software that automated the entire process. This software was built with Processing. While this sketch is very minimal, it does allow [Maurice] to set the step size and how many pictures to take in the X and Y axis. The result is easy automated micrographs. You can see a video of the process below.
Continue reading “Automating A Microscope For CNC Micrographs”
We love good pictures. You know, being worth a thousand words and all. So, after our article on taking good reference photos, we were pleased to see a reader, [Steve], sharing his photography set-up.
Taking good technical photos is a whole separate art from other fields of photography like portraiture. For example, [Steve] mentions that he uses “bullseye” composition, or, putting the thing right in the middle. The standard philosophy on this method is that it’s bad and you are bad. For technical photos, it’s perfect.
[Steve] also has some unique toys in his arsenal. Like a toy macro lens from a subscription chemistry kit. He also showed off his foldscope. Sadly, they appear to no longer be for sale, but we sometimes get by with a loupe held in front of the lens. He also uses things standard in our shop. Such as a gridded cutting mat as a backdrop and a cheap three dollar tripod with spring actuated jaws to hold his phone steady.
In the end, [Steve] mostly shows that a little thought goes a long way to producing a photo that doesn’t just show, but communicates an idea in a better way than just words can manage.
I’ve taken lots of reference photos for various projects. The first time, I remember suffering a lot and having to redo a model a few times before I got a picture that worked. Just like measuring parts badly, refining your reference photo skills will save you a lot of time and effort when trying to reproduce objects in CAD. Once you have a model of an object, it’s easy to design mating parts, to reproduce the original, or even for milling the original for precise alterations.
I’m adding some parts onto a cheap food dehydrator from the local import store. I’m not certain if my project will succeed, but it’s a good project to talk about taking reference photos. The object is white, indistinct, and awkward, which makes it a difficult object to take a good photo for reference use in a CAD program. I looked around for a decent tutorial on the subject, and only found one. Maybe my Google-fu wasn’t the best that day. Either way, It was mostly for taking good orthogonal shots, and not how to optimize the picture to get dimensions out of it later.
There are a few things to note when taking a reference photo. The first is the distortion and the setup of your equipment to combat it. The second is including reference scales and surfaces to assist in producing a final model from which geometry and dimensions can be accurately taken. The last is post-processing the picture to try to fight the distortion, and also to prepare it for use in cad and modeling software.
Continue reading “Up Your CAD Game with Good Reference Photos”
There is a family of old photographic chemistries based on iron compounds which, like the blueprint, are exposed using UV light. Ironically, the digital camera revolution which has made everything else in our photographic lives much easier, has made it harder to experiment around with these alternative methods. [David Brown] is making a UV photographic printer to change that.
[David]’s application has a lot in common with PCB printers that use a UV-sensitive resist, only [David] needs greyscale, and it might also be nice if it could work with wet paper. This makes it a more challenging project than you might think, but we like the cut of [David]’s jib.
Like some of the other UV exposer projects, [David]’s uses a rotating mirror to scan across the to-be photograph’s surface. Unlike the other ones that we’ve seen, the exposer hangs from two linear rails. Other printers move the paper underneath a stationary scanning head, which seems a mechanically simpler arrangement. We’re excited to see how this goes.
There’s a lot of interest in UV PCB printers right now. We’ve seen one made from junked CD-ROM drives on one end of the spectrum to one made by retrofitting a delta robot on the other. And don’t disregard the work done by folks interested in UV-curing 3D printers, either.
A camera slider is an accessory that can really make a shot. But when your business is photography rather than building camera accessories, quick-and-dirty solutions often have to suffice. Thus the genesis of this camera slider controller.
The photographer in question in [Paulo Renato], and while his passion may be photography, he seems to have a flair for motorized dollies and sliders. This controller is a variable-speed, reversible, PIC-based design that drives an eBay gearmotor. The circuit lives on a scrap of perfboard, and it along with batteries and a buck converter are stuffed into the case-modded remains of an old KVM switch. Push buttons salvaged from another bit of e-waste act as limit switches, and a little code provides the magic. We like the hacked nature of the controller, but we wonder about the wisdom of using the former KVM’s USB ports to connect the controller to the drivetrain; it’s all fun and games until you plug a real USB device into it. In sum, though, a nice build with nice results. Check out his other videos for more on the mechanicals.
Camera slider rigs aplenty have graced our pages, including one made mostly of wood and one controlled by a fancy iPad app.
Continue reading “Camera Slider Helps get the Shots with E-Waste Controller”