SLR lenses are intechangeable camera lenses for Digital SLR cameras. A digital slr lens will have a certain type of lens mount for a specific range of cameras.
Canon and Nikon have their own long established systems while Panasonic and Olympus share the Four Thirds and Micro Four thirds fit.
Sony use the orginal Minolta mount and have also introduced an e-mount for their new range of ILC cameras (Interchangeable Lens Compacts).
Pentax and Samsung share the original Pentax lens mount and Samsung have also introduced another mount for their NX range of ILC's.
Sigma have their own lens mount system for their DSLR camera bodies while also making lenses for other major lens mounts.
Other manufacturers such as Tamron and Tokina only make lenses for different mount types while not actually posessing their own mount.
For more information please look at our article types of SLR Photography Lenses Explained
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