Fixed Focal Length Lenses, commonly referred to as C-Mount Lenses, are used in many robotics or inspection applications. Fixed Focal Length Lenses are imaging lens assemblies designed with a single angular field of view, also known as constant focal length. These imaging lenses typically have a minimum working distance, but no maximum, extending performance out to infinity. Objects closer to the Fixed Focal Length Lens will appear larger than objects farther from the lens. Edmund Optics offers a wide variety of Fixed Focal Length Lenses and C-Mount Lenses in a range of sizes, anti-reflection coatings, sensor coverage, resolving powers (MTF), focal lengths, or working distances.
Compact Fixed Focal Length Lenses, which offer a small physical size, are ideal for automated machine vision applications. Compact VIS-NIR Fixed Focal Length Lenses also offer optimized performance in the Visible to Near Infrared (NIR) spectrums. High Resolution Fixed Focal Length Lenses are designed for compatibility with 5 MegaPixel sensors. SWIR Fixed Focal Length Lenses have been designed for optimal performance in the 0.9 - 1.7μm wavelength range.
Edmund Optics offers a wide selection of fixed focal length lenses, also called FA (factory automation) or prime lenses, in many different focal lengths options, for different sensor sizes, and in a variety of types with additional machine vision utilities.
The TECHSPEC® C Series Fixed Focal Length Lenses is the flagship family of versatile and adjustable imaging lenses designed for compact use in most machine vision applications and features focal length options from 3.5mm to 100mm. This family of lenses is also available in a wide range of other useful versions. The TECHSPEC® Ci Series Fixed Focal Length Lenses are mechanically simplified and streamlined versions of the C Series that are industrially ruggedized for instrumentation integration. The TECHSPEC® Cr Series Fixed Focal Length Lenses are stability ruggedized versions of the C Series with all optical elements glued in place and featuring a C-clamp focus ring for reduced pixel shift and improved focus stability. The TECHSPEC® Cx Series Fixed Focal Length Lenses are modular and have flexible mechanics for integrating accessories such as liquid lenses, fixed apertures, and more. The TECHSPEC® Cw Series Fixed Focal Length Lenses are IPX7 and IPX9K waterproof versions of the C Series.
Additional fixed focal length lenses adjacent to the C Series family include the UC Series (ultra-compact), designed for ≤2.2μm pixels, the 2/3” and 1.1” HP Series (high-performance), and the CA Series for APS-C format sensors. All fixed focal length lenses at Edmund Optics can be found on this page.
Imaging lenses feature a wide variety of lens mounts, all of which offer different benefits. For a more comprehensive breakdown of these types and what they are useful for, read Lens Mounts. The most common mounts used in machine vision are the C-Mount, S-Mount (M12 mount), F-Mount, TFL-Mount, and TFL II Mount. The C-Mount, S-Mount, TFL-Mount, and TFL II Mount types offer robust stability for machine vision systems whereas the bayonet-style mount of the F-Mount lends itself better to non-industrial, photography-type applications. However, the most useful mount type depends on the size of the machine vision camera sensor being used as well as the optical abilities of the imaging lens.