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Nikon MicroscopyU: Optical System and Detector Requirements for Live-Cell Imaging (7561 words) |
 | According to the Rayleigh criterion (a conservative estimate), resolution is equal to a constant (0.61) multiplied by the wavelength of illumination and divided by the objective numerical aperture. |
| For imaging multiply labeled fixed cells (and in some cases, living cells), objectives that are well corrected for chromatic aberration throughout the visible light spectrum (ranging from 400 to 700 nanometers; termed apochromats) and having a flat imaging plane (referred to as plan or plano) are considered ideal. |
| The rectangular CCD image sensor in a digital camera with no intermediate magnification factor does not capture the entire field of view as visualized through the microscope eyepiece; rather it is limited to a range between 30 and 80 percent, depending upon the chip dimensions. |
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Olympus Microscopy Resource Center: Digital Imaging in Optical Microscopy - Concepts in Digital Imaging - Electron ... (3619 words) |
| The amplified electron output from the MCP is accelerated by a high potential difference onto a phosphorescent screen that converts the electrons to photons, which are subsequently relayed to the CCD surface through an optical relay lens or direct fiber optic coupling. |
| The electron multiplying CCD incorporates a structural enhancement to amplify the captured signal before the charge is transferred to the on-chip amplifier, which has the effect of reducing the read noise, relative to signal, by the value of the multiplication gain factor. |
| Electron multiplying CCD cameras are able to detect even single-photon events when the on-chip multiplication is utilized to elevate the signal above the read noise level, and it must be recognized that any level of unsuppressed dark current is significant since it is subject to being multiplied along with the signal. |
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