Camera Obscura for Canon PowerShot ELPH115IS

myminifactory

Here's a rather large attachment that lets me use a Canon PowerShot ELPH 115 IS to capture pinhole images just in time for Worldwide Pinhole Photography Day. Specifically, it enables the little Canon to record whatever image is projected onto its built-in 150mm diagonal screen, and the front section described here turns that screen into the target of a pinhole obscura. You're probably wondering why use that Canon compact? Well, pinhole resolution is fundamentally limited by the size of the image, 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. And this particular Canon has an extra benefit - despite being a cheap and tiny 16MP camera, it can run CHDK, which means it can be programmed to do an HDR capture sequence that can easily handle the huge dynamic range caused by light falloff in an ultrawide pinhole image. The photos of the pond, dandelions, and my 101-year-old aunt were all HDR sequences done with this rig.