Digital Pinhole Camera Obscura

Yesterday was Worldwide Pinhole Photography Day. There are lots of pinhole cameras out there -- I'm not kidding: B&H alone is selling 38 models from $58 to $220! Anyway, all of those use film. So, I got inspired to produce a digital pinhole camera. Yeah, you can buy a pinhole lens for your interchangeable-lens camera (B&H has dozens of choices starting at $25), but small film formats and pinholes don't really play nice together. So, here's the little toy I designed and 3D printed to digitally capture large-format pinhole images:

This rather large 3D-printed attachment is a camera obscura: it projects a pinhole image onto a 150mm diagonal screen built-into the unit and that image is in turn photographed by an $80 Canon PowerShot ELPH 115 IS. The design to 3D print, and instructions for assembly and use, are posted as Thingiverse Thing 1515060 -- feel free to make one for yourself!

Now you're probably wondering why use that Canon compact. Well, pinhole resolution is fundamentally limited by the size of the image (well, not exactly, but close enough), so this big screen (roughly the size of a 4x5 film sheet) offers much better resolution than you can get directly using a pinhole with a small digital sensor. However, this particular Canon has the extra benefit that despite being a cheap and tiny 16MP camera (which is far more pixels than we need), it can run CHDK -- which means it can be programmed to do an HDR capture sequence that easily handles the huge dynamic range caused by light falloff in an ultrawide pinhole image.

So, how's the image quality? Pinhole-ish. With the rather coarse grain of the tracing paper I used for the obscura screen, it looks blurry, yet sharply grainy:

Then again, it's an ultrawide pinhole image that doesn't fade to black in the corners (thanks to the camera using a programmed HDR sequence) and it didn't take film and darkroom work to produce this image.

If you're thinking this is a long way to go just to produce a lousy image, well, I agree. However, it is distinctive (both the final image and the camera) and you can build the obscura for a materials cost of about $5. Better still, you heard about it here rather than as a hipster-oriented Kickstarter project talking about recreating photography from its true beginnings with Mozi in 5th century BC China, when film was just an interior wall and lenses were made out of thin air....

Very cool.  Thanks for sharing.

Tom Axford wrote:

Hank, that is the best pinhole image I have seen for some time! I think the texture of the paper adds to the image.

Thanks. I like the texture in that shot too.  It also makes it much easier for the PowerShot to focus on the screen.  

You should post it to Erik Ohlson's "Is it ART?" thread.

Ok.  Just put that and a couple more there.  The other two have the texture smoothed in post somewhat, and I agree that not smoothing it looks better....

Nice.
I used once a DSLR body cap worth a hole in it. Got some nice images.