Although there are many different techniques for correcting aberrations caused by spherical surfaces on the market, these other techniques have far less imaging performance and flexibility than aspheric lenses can provide. Another widely used technique involves adding lenses by "shrinking" them. Although this can improve the image quality, it will also reduce the light flux in the system. Therefore, there is a trade-off between the two. On the other hand, when using aspheric lens, its additional aberration correction supports users to achieve high luminous flux (low f/ and high numerical aperture) system design while maintaining good image quality. Image degradation caused by higher luminous flux design is sustainable because a slightly reduced image quality still provides better performance than a spherical system.
allow optical element designers to use fewer optical elements than traditional spherical elements to correct aberrations, because the former provides more aberration correction for them than the latter uses multiple surfaces to provide aberration correction. For example, a zoom lens with ten or more lens elements can replace five or six spherical lenses with one or two aspherical lenses, which can achieve the same or higher optical effects, reduce production costs and reduce the size of the system. Optical systems with more optical elements may have a negative impact on optical and mechanical parameters, resulting in more expensive mechanical tolerances, additional calibration steps, and more requirements for antireflective coatings.
All of these results will ultimately reduce the overall practicability of the system, because users will have to constantly add support components to it. Therefore, adding aspheric lens to the system (although the price of aspheric lens is more expensive than the same single lens and double lens), will actually reduce the cost of your overall system design.