Sigma's generic vintage 24mm f/2.8 — budget wide prime from the pre-EX era.
The Sigma 24mm f/2.8 without specific designation is a vintage budget wide prime from Sigma's pre-EX era — basic 24mm wide-angle at affordable pricing. Available for various SLR mounts.
Optically basic — typical of Sigma's budget range before the EX and Art transformations. The 24mm provides useful wide-angle. The f/2.8 is moderate. Pre-EX Sigma — before quality improvements.
Various SLR mounts. Basic construction. The pre-EX Sigma designation indicates the budget era before quality improvements. Full-frame coverage at 24mm.
Available used for almost nothing. Pre-EX Sigma lenses are basic. Modern alternatives are dramatically better. For absolute budget vintage wide-angle use only.