- #1
Paffin
- 1
- 0
Hello guys,
thanks in advance for the help.
I have come across a theoretical problem which I hope you will be able to help me solving.
It is all base on resolution (Rayleigh criterion) and Nyquist sampling theorem connected to camera capabilities.
So, resolution (Rayleigh criterion) is roughly calculated as 0.61 λ /NA (of the objective, to simplify)
The theorem of nyquist say that to sample correctly a wave you should acquire at minimum twice the maximum frequency in order to sample correctly.
Now, if a camera has pixel size of 3.75 um (side of the square pixel)
If we acquire an image with a 60x Obj with 1.4 NA for λ=480nm we get roughly 0,22 um max resolution.
Now we magnify this to 60x and we get 13.2 um, this should be the distance between imaging point on the camera optical plane.
So, our pixel size is below 2x this length and therefore we are able “to sample” this correctly without any loss.
Am I correct until here?
My question is, seems that the smaller the pixels, the better is the sampling however, is common knowledge that larger CCDs have a far better performance in terms of brightness.
My question is, what is the trade-off between the sampling ability and the sensitivity? What is the link I am missing?
Thanks for the help,
Paffin
thanks in advance for the help.
I have come across a theoretical problem which I hope you will be able to help me solving.
It is all base on resolution (Rayleigh criterion) and Nyquist sampling theorem connected to camera capabilities.
So, resolution (Rayleigh criterion) is roughly calculated as 0.61 λ /NA (of the objective, to simplify)
The theorem of nyquist say that to sample correctly a wave you should acquire at minimum twice the maximum frequency in order to sample correctly.
Now, if a camera has pixel size of 3.75 um (side of the square pixel)
If we acquire an image with a 60x Obj with 1.4 NA for λ=480nm we get roughly 0,22 um max resolution.
Now we magnify this to 60x and we get 13.2 um, this should be the distance between imaging point on the camera optical plane.
So, our pixel size is below 2x this length and therefore we are able “to sample” this correctly without any loss.
Am I correct until here?
My question is, seems that the smaller the pixels, the better is the sampling however, is common knowledge that larger CCDs have a far better performance in terms of brightness.
My question is, what is the trade-off between the sampling ability and the sensitivity? What is the link I am missing?
Thanks for the help,
Paffin