The sort of bullet-freezing high-speed video that has become familiar to YouTube audiences still requires a Phantom or Photron camera that runs well into five figures. However, there is finally a “pro-sumer” level high-speed video camera that fills the niche between 3-figure “action cameras” and those 5-figure professional cameras: The self-contained Chronos 1.4 is launching at $3,000 and offers 1.4Gpx/s throughput on a rolling 4-second buffer, which ranges from 1280×1024 @ 1,057fps to 640×96 @ 21,649fps! Aimed Research recently gave me an opportunity to test the beta version of this camera. I’ll show some of the cool things this camera can do over the next few posts.
Note that this was a beta device, and I didn’t have enough time to learn to optimize the camera at its limits. For example, here’s a 60gr .22 bullet leaving a barrel recorded at 9,000fps. With some more tweaking I expect I could have gotten the shutter speed low enough to show the bullet as a solid in each frame instead of a blur:
With time resolution in the thousands of frames per second we can see a lot of hidden phenomena. The following video of the same 10/22 rifle shooting the same 60gr .22LR bullet was recorded at 2,356fps. One surprising thing we can clearly see here is that the bolt bounces off of the breech when returning to battery.
Another thing we can see is something we heard during recent sound level testing: The unusual 60gr .22LR load is 50% heavier than the bullets for which this action was designed, and the case is 0.2″ shorter. As a result, the case clears the chamber less than 1ms after the bullet leaves the barrel, which causes a significant amount of pressure (and sound) to vent out the breech of the barrel. (A standard 40gr round doesn’t open the breech until 3ms after the bullet leaves the barrel.) If we wanted to tune this gun for this unusual cartridge, video like this would really help us confirm how changing bolt mass and spring rates affects the action.