Raspberry Pi HQ camera

Hardware
1

Hi everyone,

I am new to this forum.

I would like to build a microscope by attaching a Raspberry pi camera to an objective.
I have two questions regarding the Raspberry pi HQ camera. I found that a resolution of 0.21um/px is achieved with the raspberry pi HQ camera, which seemed to be diffraction limit.

My question are

  1. does this number um/px is really translate to better resolution in reality?
  2. Would there be any change of resolution from frames captured during a video recording to still frames?
2

Which objective? The NA of the objective is an important part of the resolution. 0.21um/pix is well beyond the diffraction limit for a low NA objective but around the diffraction limit for a high NA objective. This website provides a good explanation:

I imagine the resolution for still versus video is somewhere in the camera specification. Depending on the camera, some do have a lower video resolution than still resolution. For example 24 mega pixels for a still image versus 4MP for video.

3

The hard part of microscopy is how to aim it. What you have may be great for your application, but that’s why we still use regular microscopes with rotating turrets etc. You find at low mag, then go up, then go up more. Each 2x increase in mag reduces the area in view 4-fold, which quickly gets claustrophobic. If the sample is all the same, that might not matter, but for biology it is critical.

Video resolution is usually set lower because of shot noise. You get fewer photons per pixel when running at 30 frames per second, so binning to bigger pixel sizes cleans it up a lot. Also, you are moving a lot more data around at higher pixel counts, which can be limiting.