Blocking refers to the filter transmittance outside the bandpass region and can be thought of as the degree to which undesired wavelengths are prevented from being transmitted. Filters with deep out-of band blocking significantly enhance the signal-to-noise ratio of the system.
SPHERICAL VS. ASPHERIC LENSES
HOW THEY’RE USED IN IMAGING APPLICATIONS
Optical Lenses are often categorized by their shape. Two common surface shapes are spherical and aspherical. Each offers unique characteristics that make it suitable for different use cases.