Sam and I spent the day making a couple lenses and toying around software for the Peppy Projector.
While getting the servos under control, I made a very primitive UI that lets you move a mouse around a window to control the direction of the projector. It was weirdly compelling and felt amazingly responsive. The first lens Sam made (out of surplus optics, aluminum tubing, and a CNC-milled mount) had a fair bit of chromatic aberration:
… which was somewhat alleviated through experimentation with apertures, but at the cost of some brightness:
Thankfully, the second lens, a very extreme telephoto (same construction technique, different optics), produces crisp and bright images.
I’ll bring the prototype to CDG tomorrow and test it out in a few different locations/scenarios.
It seems like this hardware will be sufficient for us to get started in earnest on the software (calibration, dynamic unwarping, &c) and start thinking of next hardware steps. I think the next hardware element will be photographic. It would be nice to be able to take very high resolution images of parts of a scene, or instance to run OCR on an open page of a book, or to track the movement of spines on the shelf. Doing this with a similar zoom/pan/tilt camera would make sense.
Unlike with projectors, with cameras it’s not so unusual to have programmatic zoom/pan/tilt/&c. We’ll have to see if any surveillance/conference cameras meet our needs, or else we will assemble something from parts.
RMO
On May 27, 2015, at 4:55 PM, Robert M Ochshorn wrote:Sam just sent in two charming videos of the moving-telephoto-projector insert thing:IMG_3806.MOV.mov - vertical movementIMG_3807.MOV.mov - … & horizontalWe’ve swapped out the lens in the projector for a longer lens; Sam made a beautiful mount for the new lens so it fits right in:<FullSizeRender.jpeg>New lens, left, old lens, right.<IMG_3794.jpeg><FullSizeRender-1.jpeg><IMG_3796.jpeg>We may have some issues with focus in this set-up, and the lens isn’t quite as long as we want.I ordered a bunch of optics from SurplusShed, one piece of which seemed to work very well. This documentation is lacking, but here I am holding a piece of achromatic glass several inches in front of a lens-less projector:<IMG_1560.jpeg>…and here, miraculously, is Sam holding a focused & crisp image several feet down the room:<IMG_1559 (1).jpeg>We ordered some parts to turn the Surplus Shed glass into an enclosed lens; I will head into Oakland to work with Sam on that tomorrow, and then hopefully we will bring the prototype to CDG on Friday.-RMO