This one is hard to classify. Is it a hack, or is it art? Perhaps it’s both. However you want to classify it, it’s pretty cool to turn a bundle of drinking straws into a camera.

If you’re looking for the technology here, you won’t find much. There’s no lens, no shutter, and no electronics of any kind in [Mick Farrell] and [Cliff Haynes]’ Straw Camera. This is literally a box full of drinking straws standing on end, with a sheet of photo paper behind it. Each straw sends a spot of light that represents the average hue and luminance of its limited view of the subject directly to the film. The process of making an exposure consists of composing the scene, turning out the lights, loading the camera, and setting off a flash.

The resulting images are defocused but recognizable, like seeing familiar sights through a heavy fog. The straws make a strong texture over the ghostly image of the subject – indeed, the straws are the only thing in focus. The fact that the straws don’t form a perfect honeycomb due to settling and imperfections in the bundles is jarring at first, but as you see the images you get used to the extra texture.

When we first saw this, we wondered about the possibility of putting a simple photosensor at the bottom of each straw to capture similar images digitally. The TCS3200 would be about the right size, but given that there are about 32,000 straws in the bundle, the BOM might get a little out of hand. Still, a scaled down digital straw camera might yield some interesting images.

Thanks to [Stuart Rogers] for the tip.

There is an easier way to do that, Aluminium “Honeycomb Core”.

http://www.hongzan.net/uploads/Products/Honeycomb_core/fengwoxin5.jpg

I think you will get interesting results by dipping some or all of it in ultra black paint too, all, bottom or top third. You’d need to experiment to see what effects it gave you.

You can get 1 x 1 meter sheets with 1mm cell size, https://www.alucrown.com/product/micro-aluminum-honeycomb-core/

Put a layer of glass between the paper and the sheet of cells and you can eliminate the effect of the cell wall thickness if you need a more seamless effect.

Aluminum honeycomb is “easier”, maybe, but from what I’ve seen, it’s about 300 USD per square foot (300 mm x 300 mm) for a piece that’s only about an inch thick (26 mm) and a cell size of 6.3 mm which wouldn’t produce a good image. The straws are probably going to be drastically more cost-effective and produce a sharper image due to their superior length:diameter ratio.

You can roughly estimate the angular resolution of a device like this by arctan[diameter / length] which for the aluminum honeycomb mentioned above would give no better than about 14 degrees angular resolution. This is bad.

However, using drinking straws, even this very coarse one I have on hand, from Wendy’s that’s designed for attempting to suck melted Frostys (yeah, just try sucking one fully frozen) is 7 mm x 230 mm, which gives an angular resolution of about 1.7 degrees. Way better. And you could do even better by buying slenderer straws.

(This can be calculated in Frink by: https://frinklang.org/fsp/frink.fsp?fromVal=arctan%5B7+mm%2C+230+mm%5D&toVal=degrees&keep=1#calc )

I use diazo (blueprint) paper and various jury-rigged homemade “cameras” to take pictures, including a pinhole camera (incredibly slow) and a lens jammed into a toilet paper tube that can be focused (by sliding it in another toiler paper tube) to take pictures inside a cardboard box “camera” (maybe 15 minutes exposure). Since the time it takes to expose the diazo paper is a function of the aperture size, a drinking straw camera would be incredibly faster and more efficient, and you could easily make a “camera” that would expose a giant piece of blueprint paper in seconds or minutes. (I use sheets that are 42 inches by 30 inches and they’re dead cheap. Also, all you need to do to “develop” them is expose them to ammonia fumes for a few minutes.) In direct sunlight, diazo paper gets exposed within a few seconds.

I think I should build a giant soda straw camera for use with blueprint paper. It’s drastically simpler and less expensive than using photo paper for a first attempt.

I think you will find that reading the info on the page I provided the link for would give you a much better idea of what is actually available. The range covered is from 0.6 mm right up to 30 mm. You don’t need aerospace grade material, cheap architectural panels from China will do.

So using your math and the actual panels available you get a better result,

From: arctan[.6 mm, 26 mm] To: degrees Result: 1.3219756595369824017

Thanks. What is the price for those? Your links do not list consumer prices.

So, can you quote me an actual price on a piece of aluminum honeycomb with these specifications (.6 mm honeycomb, 26 mm thickness) that is the size of my diazo paper: 42″ x 30″ (106 cm x 76 cm)?

I have a feeling that it costs hundreds of times more than drinking straws for the same resolution.

Again, the important factor is price/resolution. Anyone can pay anyone to make smaller light pipes or narrower honeycomb channels (down to fiber optic light pipe dimensions), but can you make it cheaper than the drinking straws in the article for the same resolution?

I could pay thousands of dollars for aluminum honeycomb. But why would I, if I can get the same or better effects from a few dollars of drinking straws?

Dude, I’m not your mother, do your own shopping. Try the usual big Chinese eCommerce sites.

Sadly Alan never met his mother and her name was Dan, so you might be.

The cost is $730. You’re both welcome.

Dan, if it’s you, please come home.

Compulsive trolling is a sign of mental illness, Alan. Grow up.

The paint is the interesting question here, and that could be tested with the cheaper straws, too.

I’m actually shopping for honeycomb material for another project (catching a fountain spray without splashing), and searching around the usual suspects, I find pre-cut pieces with edge treatment, intended to go over camera flashes and studio lights, to “make the light more directional”. Most of them look like they’re either painted or anodized black, so testing the whole-depth-painted idea might be as simple as ordering an existing product and waiting.

I bet a 5mm photodiode would fit in a straw nicely.

If you could create a circuit that could scan such low voltages, you could scan basic silicon diodes in the mV range to detect light. It’s $221 from digikey to buy 30000 1n4148 silicon diodes. It’s true that they are not ideal light sensors, however, if you can create a circuit that can scan them and read the mV range generated when light hits them (you’d need bright lights), it might actually work. Maybe. I don’t know what wavelengths they react to. You could possibly get color using lots of little filters, but again, not sure what wavelenghts are reactive, or how much losses you’d get. I think you’re only talknig 4-5 mV with a flashlight shining right on the thing… So maybe you’d even need to be able to sense int he microvolt range…

If there’s a will though…

You’ve just described a CMOS* sensor and a Bayer filter :)

*Other Semiconductor types are available with different wavelength responses – https://en.wikipedia.org/wiki/Photodiode#Materials

“If there’s a will though…”

There’s a dead relative? That’s what my father always told me.. Its helped get things done for years!

You can use led’s to detect light too, If you want to go further you can use RGB LED’s to detect colour also, I’m sure if you connect enough together into a matrix you could “take a photo” so long as you have a circuit to detect low mV and perhaps a microcontroller for timing and recording voltages so you can later develop photo on laptop or might be able to to it in the microcontroller (not sure I could though).

Isn’t it similar to how Lytro cameras work?

Not really. This recieves all of the light that’s travelling in one direction. Lytro-style LFCs capture every ray that goes into the aperture from *any* direction, recording brightness and direction.

You could write some simple software that would turn a Lytro into this, though.

Can it be done, for example, by rotating the camera (with stepper motor?)

Well, if you don’t mind rotating the camera, then you can just use one row of straws with a phtodiode or LED in each straw, and scan physically.

You can take 5mm phototransistors and sample the brightness through a resistor divider. Scan the matrix by pulling the emitters to ground, multiplexed.

Yep, it can. Bunch of straws is called a collimator. It’s typically used in nuclear physics imaging instead of lens. https://en.wikipedia.org/wiki/Collimator

That’s what I was thinking too.

22mm drinking straws!? Really? Do they come with supersize 2 gallon soda? My garden hose is 22mm.

Sorry, what are you replying to? I don’t see anything there that refers to a 22 mm diameter pipe. Are you confusing diameter of the straws with the length?

“… where a 254mm long, 22mm wide straw gives an aperture of about f127 …”

You have a very short garden hose.

And a small garden. ;-p

Or you get a Spectral Instruments 800 Series 16Mpixel Cooled CCD camera Electric teardown from the Famous Mike:

Aparently hackaday cuts the time index from the video. Picture of the light pipe @38s into the video.

I see no one is mentioning 3d printing a long hexagon grid for this. I’m already modeling it, though I don’t have any photo paper.

I almost wonder is a thin sheet of translucent white plastic on the back of this coupled with a DSLR with a remote flash could be used to test the camera to make sure a given straw arrangement worked. I know it would essentially be a camera taking a picture of a camera but for testing purposes it should work.

Lol, now I’m thing of making a straw “lens” for my DSLR with a Fresnel lens immediately behind the straws to focus the image onto the DSLR sensor. Would be utterly ridiculous as a lens but might be fun for artistic shots.

Oh wow… I should totally do that… I also have a couple magazines of B&W and color polaroid film I bought a few years ago to mess around with a polaroid back I found for my old Nikon 35mm…I bet that’d work. (Better than not, anyway.)

Let me save you the trouble of designing it… http://www.thingiverse.com/thing:9184

Thank you Stuart for sending this in, and Dan for publishing it. It’s a refreshing diversion from the usual Ardu-berry-8266 fare, and while those projects often hold tips and ideas for small optimizations to existing designs, this one has inspired a whole bunch of readers to consider a whole new way of thinking about imaging. The comments section here is smaller than most but dense with ideas, and that’s simply awesome.

With small enough/long enough straws, could you get an almost orthographic projection camera?

You should, if you paint the insides of the straws black, which also improves your contrast, anyway. But keep in mind that if you’re eliminating reflections, the longer the straws, the less light you get.

I have been wondering if you could build a telescope this way.If built to a 10 by 10 m^2 and each straw was 1 pixel by having a photo sensor in the end of each straw.

Stars are separated by angular direction, and the system detects light from only single angle. Stars are far enough that if you direct it at some star, all straws will see the same light intensity (maybe excluding atmospheric scintillation). But with rotating the device and/or using Earth rotation, imaging is possible.

One could try a bundle of small bore capillary tubing. I see some relatively thin walled stuff is available on the market.

You can get higher resolution with coffee-stirring ‘straws’. https://www.walmart.com/ip/Bulk-Buys-Coffee-Stirrer-Straws-Case-of-24/30430613

Interestingly enough, with a complete lack of normal perspective this camera is perfect for portraits. You can put the camera next to the subject and nobody’s nose is going to end up gigantic.

So aside from the technical aspects does anyone think this is what insect vision must look like?

Vision is perception, which means it involves both photoreceptors and signal processing. My guess is that insect vision looks a lot like human vision.

What would a bundle of fibre optic filaments do? Does anyone know?

It would bounce all diffuse light to the sensor. The trick is to use the straws as filter for light that does not go straight in to the straws. That’s why they use black straws. But matte black would even be better.

Actually just recently there was such a thing on “Play with junk”: https://youtu.be/H4A9n7hK3Mc I tried to do an approximation of this when I was little, but I could never arrange more than some 10 fibers. This thing has a huge amount of them.

I think this would be similar to the DARPA Gorgon Stare + Argus IS processing/detection software. Gorgon Stare = Camera head end and Argus is the thing that takes the mosaic of images and re-assembles them into something useful.

I think the image is “unfocused” not “defocused”, which isn’t a word and should be hyphenated. And implies it is focused at some point in the optical path. Believe your spellchecker.

And it isn’t an image, as in an optical image. The brain can estimate an image from the array of colored circles. It isn’t even a convolution of light from all the straws since there are boarders and it does not spread beyond the straw. With some space between the ends of the straws and the paper, you can describe the results as a convolution. You could analyze with the mathematical tools of image processing, which has very likely been done for glass fiber bundles used in all kinds of imaging.

Use a flatbed scanner for imaging? Obviously not practical for portraits but still life…

what about rip cutting some 2MM coroplast sheets? http://www.coroplast.com/products/graphicarts.htm

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