As cameras go how many pixels are just enough?
As technology advances, cameras gain more pixels and prices get cheaper…so how many pixels are enough and after which more pixels offer diminishing returns?
Thanks
So how many pixels are enough?
Re: So how many pixels are enough?
Number of pixels is unrelated to diminishing returns (as long as total sensor size is inside plan region). Size of pixels is what matters for sampling. What size of pixels is sampled correctly, depends alot on the optics you use on a case by case basis. The reason why you hear people say "above x MP you get diminishing returns" is generally when they are talking about a set total sensor size, where more pixels = smaller pixels, and smaller pixels are where diminishing returns happen. Its a dangerous misconception, because not all sensors are the same size!
With that said, there's some other information to go over.
For OSC (one shot color), pixels should be treated like they are 2x larger, due to the Bayer pattern.
notice how blue and red are spread out? that means you have to sample for pixels twice the size, to sample red and blue not just green correctly.
To calculate the resolution, use .61 x wavelength / numerical aperture. For wavelength, 550nm is used as a standard green value, but ideally you would want to be properly sampled even into blue.
To calculate size each Bayer pattern occupies use pixel size * 2 / total combined magnification. The total magnification would be the mag of the objective, multiplied by any other optics.
With that said, there's some other information to go over.
For OSC (one shot color), pixels should be treated like they are 2x larger, due to the Bayer pattern.
notice how blue and red are spread out? that means you have to sample for pixels twice the size, to sample red and blue not just green correctly.
To calculate the resolution, use .61 x wavelength / numerical aperture. For wavelength, 550nm is used as a standard green value, but ideally you would want to be properly sampled even into blue.
To calculate size each Bayer pattern occupies use pixel size * 2 / total combined magnification. The total magnification would be the mag of the objective, multiplied by any other optics.
Re: So how many pixels are enough?
This depends on the planed use of the pictures taken.
For websites only 3 MP are well enough. For wall sized prints you need much more.
More important are data transfer rates and sensor size.
Forget any USB 2 camera. Data transfer is to limited making them a pain to use. USB 3 allows smooth working.
The sensor size should fit the plan field of viewing. A sensor too small will crop the picture. To compensate you need some adapter optics and they are either very expensive ore of very terrible quality.
On most scopes a sensor size of Micro 4/3 or 1'' will give proper coverage without the need of additional optics. 2/3 may be ok but anything smaller requires adapter optics. Most microscope cameras feature very tiny sensors.
Bigger sensors than micro 4/3 result in vignetting most of the time but that's easy to correct in post processing.