HermannSW

16 ms·

1.
by HermannSW 7y ago
Thanks Robert for the youtube videos and the blog, hopefully many more people will play with high framerate video capturing by that. But 660fps is not the end for v1 camera, I added section "kFPS videos from kEPS multiple exposure fram
2.
by HermannSW 7y ago
True, and he started with 1/100,000 second exposure time humming-bird images 83 years ago! The MIT group used a flash with 0.5us exposure time. I asked for details without answer yet, but assume that it is costly (Vela One does cost 94
3.
by HermannSW 7y ago
Really? USB2 is 300Mbps for PI3 ethernet over USB2, is it faster with hdd? I ask because snail 35MB/s is 280Mbps.
4.
by HermannSW 7y ago
No answer on the networking forum yet. I cannot try because I don't have a Pi4 yet. It seems possible. An easy test would be to test whether this command will work on Pi4: raspividyuv -md 7 -w 640 -h 480 -t 0 -fps 90 -o - | nc someIp s
5.
by HermannSW 7y ago
> I'm just trying to find what shutter speed you can get with the Pi camera. You can reduce the shutter time nearly arbitrarily, as long as you increase light intensity. I did place fast rotating propeller just above a 5000lm led, a
6.
by HermannSW 7y ago
A group of MIT students did synchronize 16 PIs with 16 cameras just over GPIOs to shoot at exactly the same point in time. And they built in microsecond delay for adjusting on when exactly the bullet has passed through apple and leaves: ht
7.
by HermannSW 7y ago
There is no Pi with 10G ethernet. New Pi4 has only Gigabit ethernet, Pi 3B+ has Gigabit Ethernet over USB 2.0 (maximum throughput 300 Mbps). The idea is interesting, did some calculation. For v1 camera capturing 640xH frames can be done at
8.
by HermannSW 7y ago
I was wrong, the 9$ are for NoIR camera with M12 lens mount and lens. I just ordered 4 new NoIR cameras for 2.84$(!) including shipping! https://www.aliexpress.com/item/32946093276.html
9.
by HermannSW 7y ago
There is a drawback with Raspbian, while Raspbian itself is open source, the GPU code is closed source and you cannot debug it. What you can do is to reverse engineer the I2C traffic from Raspberry GPU to camera (that is one-way): https:&#
10.
by HermannSW 7y ago
Yes, there are NoIR versions of v1 camera, they just miss the infrared filter normal cameras have (around 9$ on aliexpress.com). And there are 12$ versions of v1 camera with (hardware) IR-cut filter, depending on photo sensor on camera IR f
11.
by HermannSW 7y ago
Yes, for objects moving with high speed vertically, rolling shutter capturing produces weird frames. But v1 camera can do "global external shutter" as well. See examples on "extreme rolling/global external" shutter
12.
by HermannSW 7y ago
I think that would be possible, just a problem of adjusting all cameras to get overlapping FOV. There was a MIT student project group that took 16 v1 cameras(!) global external shutter frames and created an animated .gif from that! "Ul
13.
by HermannSW 7y ago
Yes, you can do 320x240 with modified raspiraw parameters. But you will get the same framerate as for 640x240, for v1 as well as for v2 camera. You can do the opposite and increase horizonatal resolution for line scanner type of application
14.
by HermannSW 7y ago
You can get Raspberry v1 camera clone now for less than 4$(!) with free shipping on aliexpress: https://www.aliexpress.com/wholesale?SearchText=raspberry+5M... And unlike v2 camera, the cheap v1 camera allows (besides high
15.
by HermannSW 7y ago
Deal is "halve vertical resolution and get roughly double framerate", see here for more information: https://news.ycombinator.com/item?id=20633504
16.
by HermannSW 7y ago
Find diagram showing the achievable framerates for 640xH frames for v1 and v2 camera here: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=2125... Deal is basically "halve vertical resolution, and get
17.
by HermannSW 7y ago
Easiest way to avoid flicker is to light the scene with 1000lm or 5000lm cheap leds with led driver (they power the led with 38V/1.5A DC for 5000lm). Total cost of led+driver is less than 9$ with free shipping on aliexpress.
18.
by HermannSW 7y ago
You can do 640x64@665fps with v1 camera, and 640x128@667fps with v2 camera: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=2125... In tools directory you can use *_s tools to get double FOV vertically whil