How many pixels I need in my camera?
Human visual acuity is ~ 0.3mrad, so for a 30cm screen at comfortable viewing distance, ~ 1600 by 1600 pixels are the maximum needed. The more pixels you have, the higher readout speed you need. The higher readout speed you have, the more noise you have. Hamamtsu ORCA AG has 1344(H) x 1024(V) effective number of pixels, which is comfortable for viewing your computer monitor.
How big a pixel I need in my camera?
Assuming your microscope is set up with a 50x N.A. 1.4 objective, coupled to a CCD camera through a 1.5x relay lens. Assuming a wavelength of 500 nm (green), the objective is expected to deliver a resolution of approximately 0.3u. With an overall magnification of 1.5x50 = 75, the smallest resolved spacing will represent 15u at the camera plan. The digitization interval must be small enough to sample the smallest spacing with 2.5 to 3 pixels ( Naquist Sampling Theorem). Hamamtsu ORCA AG cell size is 6.45u x 6.45 u, just the correct range for most demanding microscope.
How much noise I need in my camera?
You don't need noise at all, yet you can't avoid it. There are several contributions for noise, such as dark current, readout noise, noise from the amplifier, etc, but what really interest you is the overall noise. This is best calculated from the Dynamic Range specification. Dynamic Range is defined as full well capacity : total noise. For ORCA-AG, dynamic range is specified as 3000:1. Since Full Well Capacity For Orca-AG is specified as18000 electrons, total noise = 6 electrons, (18000: 6 =3000). Readout noise is most dominant contributor, as it is specified by 6 electrons, all other noises are negligible. Some companies specify Dynamic Range in bits. This specification is misleading, as it just meant, Dynamic Range is below 255 in case of 8 bits, below 1023 in case of 10 bits etc.
