tl;dr: Gamma Camera is my open source flexible camera array project and you can build your own with https://github.com/robrussell/gamma. I made a thing I call Gamma Camera. What is it? It’s easiest to explain starting from my motivation. For the past few years I’ve been tinkering with a lot of commodity camera parts and single board computers like the Raspberry Pi and Jetson Nano. I’ve also spent a lot of time trying to get a better handle on algorithms like structure from motion (SfM) and, more recently, neural radiance fields (NeRFs).

There are a bunch of ffmpeg commands I find myself copying and pasting over and over. Maybe you do too. Here are mine. I’ll explain the flags for this first one in a lot of detail, if I skip a flag on another example then it’s probably described here. And I’ll link to some more thorough docs at the end. ffmpeg -i /mnt/nas/photos/PXL_20230128_171859165.mp4 -vf select='between(t\,200\,210)*eq(pict_type\,I)*gt(pts-prev_pts\,0.500)' -vsync 0 -frames:v 100 /mnt/nas/frames-PXL_20230128_171859165/img-%03d.jpg Flags

Here’s another camera mounting block to 3d print. This part is meant to go with my previous design for mounting a Raspberry Pi on a t-slot rig. It’s just the minimum bit of plastic needed to join the camera module v3 to a 1/4-20" nut. Then the nut can be used to attach the camera module to a ball head like this one from Small Rig. Just like the rest of Gamma Camera the idea is to use 3d printed parts to bridge between common COTS parts.

My t-slot obsession has not let up. Last night I made a nice little design to easily secure a Raspberry Pi to a piece of 2020-profile extruded aluminum. This follows on from the 1/4"-20 to t-slot mount that I made recently. Just like that component, I used BOSL2 in OpenSCAD to quickly put it all together. Design Here’s the design for the part if you want to have a look.

Storage prices have dropped drastically since I built my Gamma Camera array. As I mentioned a little while ago, I’m interested in USB storage for the next iteration. In gammacam P6 I have 6 Raspberry Pi 4B nodes. The microSD card holds the OS and also the imagery data. I have heard that microSD card speeds are slower than USB options. And lately I’ve noticed that prices for some pretty fast storage options have been falling.

Three things from this week. This week I’ve got three little progress updates on the next gammacam build. Updating the sensor head I thought I was going to need to change the design of my camera head a bit to fit the Raspberry Pi GS camera module.It turns out that the sensor head will work fine as-is. The plastic cover on the back of the GS camera module is easily removable.

Three things from this week. Raspberry Pis are showing up in stock more often. So I have to get to work and start building the next version of my Gamma Camera rig. I’ve been thinking about it for so long that I’m afraid of falling into second system syndrome. I guess it’d be seventh system syndrome in my case… I’ve got a lot of half-complete thoughts about what I want to put into the next rig so here are three of my best ones.

Three things from this week. While I was on vacation I was taken by a notion that I really wanted to be able to make some of the music in my head come out of my fingers. I’ll often get some tiny fragment of a song in my head and I don’t usually know many lyrics to go with it. So I just have a little ditty running around in there.

Three things from this week. Here are three things I learned this week. They are not related. Embeddings Vicki Boykis generously shared her research on “What even are embeddings?” in 80 pages of PDF written at just the right level for me. I’d highly recommend it if you too are tinkering with ML models and feel like you have some jargon gaps to fill in. Since I was on a plane a couple times I was able to pay attention long enough to read the whole thing and run some of the sample code.

Three things from this week. Still travelling through Scotland this week so you get to see three more things this week that I saw. The Isle of Skye is full of stunning landscapes. I loved hiking the easy part of the Quiraing. I was confused by the Old Man of Storr. I was recharged visiting the rushing waters of the Fairy Pools. The Quiraing name (or Cuith-Raing in Gaelic) comes from old Norse languages and describes the folded structure of the land.