Patent ID: 6870687
Filing Date: 2005-03-22
Classification: G02B

Abstract:
1. An optical system with a wavelength selecting device comprising, in order from an object along an optical axis: an objective optical system composed of optical elements having refractive power and an aperture stop; a no-power optical group composed of optical elements having no refractive power; and an imaging device; the no-power optical group including a wavelength selecting device having a light transmittance spectrum with a short wavelength portion and a long wavelength portion, the wavelength selecting device transmitting substantially only visible light and being selectively substantially non-transparent with respect to light in part of said short wavelength portion and light in part of said long wavelength portion, said wavelength selecting device including an absorption filter; wherein the following conditional expressions are satisfied:  390<λ V50 <430 where λ where λ where λ