Identification
The ring around the front of the lens will have "CANON ZOOM LENS EF 75-300mm 1:4-5.6 III". Canon has 7 variations of the 75-300mm lens, so make sure that the name contains "III" and does not contain "USM".
Technical Specifications
General:
- Focal Length: 75-300 mm
- Maximum Aperture: f/4-5.6
- Minimum Aperture: f/32-45
- Closest Focusing Distance: 1.5 m (4.92 ft)
- Maximum Magnification: 0.25 x
Construction:
- Lens Groups: 9
- Lens Elements: 13
- No. of Diaphragm Blades: 7
Physical:
- Lens Mount Type: Canon EF
- Filter Diameter: 58 mm
- Maximum Diameter x Length: 71 x 122.1 mm (2.8 x 4.8 in)
- Weight: 480 g (16.8 oz)
Accessories:
- Lens Cap: E-58 II
- Lens Hood: ET-60
- Soft Case: LP1019
- Magnification - Extension Tube EF12 II
- Magnification - Extension Tube EF25 II
Source: Canon Camera Museum Webpage