Raspberry Pi High Quality Camera takes photos through thousands of straws
Adrian Hanft is our favourite kind of maker: weird. He’s also the guy who invented the Lego camera, 16 years ago. This time, he spent more than a year creating what he describes as “one of the strangest cameras you may ever hear about.”
What’s with all the straws?
OK, here’s why it’s weird: it takes photos with a Raspberry Pi High Quality Camera through a ‘lens’ of tiny drinking straws packed together. 23,248 straws, to be exact, are inside the wooden box-shaped bit of the machine above. The camera itself sits at the slim end of the black and white part. The Raspberry Pi, power bank, and controller all sit on top of the wooden box full of straws.
Here’s what an image of Yoda looks like, photographed through that many straws:
Ground glass lenses
The concept isn’t as easy as it may look. As you can see from the images below, if you hold up a load of straws, you can only see the light through a few of them. Adrian turned to older technology for a solution, taking a viewfinder from an old camera which had ground glass (which ‘collects’ light) on the surface.
Even though Adrian was completely new to both Raspberry Pi and Python, it only took him a week of evenings and weekends to code the software needed to control the Raspberry Pi High Quality Camera.
An original Nintendo controller runs the show and connects to the Raspberry Pi with a USB adapter. The buttons are mapped to the functions of Adrian’s software.
What does the Nintendo controller do?
In his original post, Adrian explains what all the buttons on the controller do in order to create images:
“The Start button launches a preview of what the camera is seeing. The A button takes a picture. The Up and Down buttons increase or decrease the exposure time by 1 second. The Select button launches a gallery of photos so I can see the last photo I took. The Right and Left buttons cycle between photos in the gallery. I am saving the B button for something else in the future. Maybe I will use it for uploading to Dropbox, I haven’t decided yet.”
A mobile phone serves as a wireless display so he can keep an eye on what’s going on. The phone communicates with the Raspberry Pi connected to the camera via a VPN app.
Follow Adrian on Instagram to keep up with all the photography captured using the final camera, as well as the prototypes that came before it.
KENT ALEXANDER JOHANSEN
It’s the same principle for a parallel hole collimator on a gamma camera detector used in nuclear medicine.
Raspberry Pi Staff Ashley Whittaker — post author
I am just going to have to take your word for it on this one, Kent, but, sounds cool if true!
I was just going to say that – well, not exactly that, but similar. Although this may be just a curiousity, in this case, for x-rays, lenses are hard to come by, so this would be a genuinely useful approach for an x-ray camera.
Many years ago I was involved in the manufacture of a series of chemically milled stainless steel plates that were stacked together to form an x-ray collimator for a camera that flew on a space shuttle mission. Each plate had an array of slots along with a hole at each corner for a machine screw to pass through.
I worked on X-ray detectors at Leicester University Space Research Dept. Early X-ray satellites like Exosat used collimators originally with metal foils to create a honeycomb structure, but later, the flight model used microchannel plate technology. Glass rods consisting of soft glass in a lead glass tube were stacked, fused, stretched like Blackpool rock, chopped, stacked again etc. The final fused tubes were then chopped into plates and the soft glass etched out to leave an array of tiny tubes which acted like the raspberry pi camera but for unfocussable hard xrays. Deja vu?
Richard and Papazian
Takes me back to the early 1970’s when I worked on Bairds System 70 Digital Gama Camera. the parallel hole collimator kept the back and side scatter from affecting the images.
KENT ALEXANDER JOHANSEN
No wait, a converging hole collimator ?
I really like this :-) But does it need to be the raspberry pi high quality camera? Surely the standard raspi camera or even a regular digital camera could be pressed into service?
Very impressive and very original. Big thumbs up.
Imagine how many sea turtle lives could be impacted if this becomes a more popular form of photography
Actually it’s a compound eye. Examples found as fossil trilobite as well as insects.
so the same principle as fiber optics? Light is bent, or condensed by a flexible surface, or pipe.
Nope. Optic fibres use total internal reflection inside the fibres. Here you’re only getting the parallel light that comes directly through the tubes. The ground glass is functioning as a focussing screen for the light coming through the straws, and the camera is taking a photo of the resulting projected image.
Exactly. Side effect being that it acts as if the camera had infinite focal length. The objects it sees aren’t therefore skewed like in a normal camera/lens that actually sees every pixel with a different angle.
A higher resolution version of this could be made out of fiber optic cables – only the cores. These would have to have its ends perfectly smoothed at right angle, though.
Interestingly, Kristian Akseth has used something similar to make a wind tunnel with pure laminar flow for testing. He bought dozens of packs of restaurant straws– which come as blocks, tightly wrapped in brown paper– used a band saw to take the ends of the entire block off, and basically built a wall out of a few layers of them. He stuck a big fan in front, and the air that came out the other end had almost no turbulence. A little smoke in front, and presto, perfect wing visualizations.
To some degree, this kind of imaging can do something similar, eliminating off-axis light. Should be very interesting to play with.
How it Works (or similar) also did similar with water to get a laminar flow and make some dancing fountains, I think that’s also how the big Las Vegas ones work.
Interesting look! Maybe it’s part of the charm of the final image… but (I suppose due to ground-glass properties) it has a big brightness peak at center and vignetting around the edges. That could, I presume be reduced in post, if you wanted to.
That’s a hooooge amount of effort to convert a high-res camera into a low res camera. So: It has to be capital-A Art, right?
Could have been done just for fun.
I love the resulting photos…though I hope it was 23,248 paper straws.
If I’m reading this right, there’s a plate of normal glass, then the straws and then a plate of ground glass. The straws work like pinhole cameras and ‘project’ the image onto the ground glass plate. The camera then takes a photo of the ground glass plate.
Another element for an optical computer CPU if it isn’t already ?
Pure optical TV sans the need for optical to electronic conversion.
Looks great – shame they weren’t paper straws though :-(
The post would have been more interesting if it had actually answered the question “What’s with all the straws?”, instead of just mentioning how many of them there are.
I read through the whole text and still don’t understand their purpose, nor how the “ground glass viewfinder” helps the problem described. How do they act as a lens? Other comments say they act as a collimator, which is at least intuitive, but then I don’t see how the light reaches the sensor.