Canon's budget telephoto with USM motor — faster AF than non-USM versions but still optically poor.
The Canon EF 75-300mm f/4-5.6 USM was the original USM version of Canon's budget consumer telephoto zoom, released in 1992 as one of the first Canon EF zooms with a USM motor — providing faster, quieter AF than the DC motors of contemporary entry consumer lenses. The USM motor in this version is a micro USM design. On APS-C the 75-300mm covers 120-480mm equivalent. This is the first version of the 75-300mm lineup; the II USM (1995) and III USM (1999) followed as successive updates.
The optical design uses 13 elements in 9 groups. The 58mm filter thread is consistent across the 75-300mm family. At 495g the lens is moderate for a 300mm consumer telephoto. Minimum focus distance of 1.5m. Micro USM motor provides AF — note that unlike ring USM, full-time manual focus override requires switching to MF mode. No Image Stabiliser. Variable aperture from f/4 at 75mm to f/5.6 at 300mm.
The 75-300mm USM's practical case is as an entry full-frame or APS-C telephoto in adequate daylight. Without IS, minimum shutter speeds of 1/300s at 300mm (full-frame) or 1/480s on APS-C are required for sharp handheld results. For outdoor sports, wildlife, and events in good light, the lens provides coverage at very low cost. The micro USM motor is functional and reasonably fast for static subjects.
On the used market the EF 75-300mm USM (original) is very affordable. Condition checks: micro USM AF response, zoom ring smoothness, and front element for marks. The EF 70-300mm IS II USM provides IS and Nano USM at a moderate premium. Blade count may vary between the original USM and the II USM versions — confirm with the specific copy if this matters. Compatible with all Canon EOS DSLR and R bodies via EF-RF adapter.