sagigene
Posts: 1
Joined: Thu Oct 10, 2019 5:29 pm

Regarding recosrding brownian motion.

Thu Oct 10, 2019 5:37 pm

I want to record brownian motion of colloid by attaching the Raspberry Pi 8MP Camera Module V2 to objective lens 40X of microscope.

What is the fps capacity of this camera?
Will I be able to record the Brownian motion?

Thanks:)

User avatar
HermannSW
Posts: 1512
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
Contact: Website Twitter YouTube

Re: Regarding recosrding brownian motion.

Fri Oct 11, 2019 2:39 am

> What is the fps capacity of this camera?
>
What resolution do you need?
With v2 camera you can capture 640x480@120fps, even up to 200fps with restrictions, see v2 table:
https://www.raspberrypi.org/documentati ... /camera.md

I use 640x480@150fps with 0 frameskips and no changes to automatic exposure, even with only 50µs shutter time to minimize rolling shutter effect (very bright light needed). 150fps video animation is played @5fps, 30× slowed down. Disk rotates with 283 rotations per second:
https://www.raspberrypi.org/forums/view ... 2#p1543111
Image


See this posting on bigger frames, you can capture 10s of 3280x2464 at 15fps into ramdisk on Pi4B without frameskips.
And you can capture arbitrary length .h264 1640x922 video onto SD card at 40fps:
https://www.raspberrypi.org/forums/view ... 3#p1550143

> Will I be able to record the Brownian motion?
>
Yes, with the available framerates.

Brownian motion is fast, I once did capture really really slow air bubbles moving in spittle with my RPI microscope.
Frame resolution was 0.7µm per pixel, speed was 0.347µm/s!
Playback speed is 25× increased:
https://www.raspberrypi.org/forums/view ... 8#p1409065
Image


P.S:
You can use raspiraw to capture with much higher than 200fps, up to 1007fps for 640x75 frames with v2 camera:
https://www.raspberrypi.org/forums/view ... 5#p1320034
Image
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://gitlab.freedesktop.org/HermannSW/gst-template
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

Return to “Camera board”