Operating conditions include items that pertain to the whole lens, or describe its conditions of use. The stereotype operating conditions are the ones used to specify the aperture and field of view. OSLO includes many other operating conditions, some of which (e.g. wavelengths, error function) have traditionally been included as operating conditions in all optical design programs. Other OSLO operating conditions are new, and have been included to more completely describe the complete design (e.g. element drawing data), to enable consistent analysis (e.g. spot diagram operating conditions), or to eliminate extensive data re-entry (e.g. lens drawing operating conditions).