Multispectral imaging has a great number of applications. Large 2-dimensional silicon focal plane arrays (FPA's) containing several million detector elements are able to image radiation from ~350nm to ~l,000 nm. (Other detector materials are applicable at other wavelengths.) A remote sensing instrument with an afocal telescope, a filter wheel, focusing optics, and one or more FPA's is an attractive method for performing imaging multispectral remote sensing. As the number of spectral bands increases, the size of the filter wheel must also increase, relative to the size of the telescope's exit beam. The subject invention is an improvement over the prior art in multispectral imaging technology implemented with a filter wheel. It allows the filter wheel to rotate continuously at a constant, high angular velocity, so that a series of frames can be exposed, and minimizes the dead time during which more than one filter is in the optical beam's path. It allows an FPA to be exposed to the image and them to have its data read out without requiring an additional shutter