Canon EF 75-300mm f/4-5.6 III Lens

Canon EF 75‑300mm f/4‑5.6 III Lens is a classic telephoto zoom lens designed for Canon EF-mount cameras, making it compatible with both full-frame DSLRs and APS-C bodies (which provide an effective focal length of 120–480mm). It is a budget-friendly lens aimed at entry-level and enthusiast photographers who want the ability to reach long distances without investing in professional-grade telephoto glass.

Optical and Mechanical Design

The lens features a 13-element, 9-group optical design, balancing weight and performance. It weighs approximately 480 grams and measures about 122 mm in length, making it relatively compact and portable for travel, outdoor shooting, and field photography. The maximum aperture ranges from f/4 at 75 mm to f/5.6 at 300 mm, suitable for daylight shooting. Stopping down further allows deeper depth of field but reduces light intake.

Autofocus and Aperture

Autofocus is driven by a DC micro motor, which provides adequate performance for still photography but is slower and louder compared to USM or STM systems, especially when tracking moving subjects or recording video. The lens features an electromagnetic diaphragm with seven blades, creating smooth out-of-focus areas (bokeh) at longer focal lengths.

Lens Coatings

Super Spectra coatings are applied to reduce flare and ghosting while enhancing contrast and color accuracy. These coatings are particularly beneficial for outdoor shooting where harsh lighting conditions can affect image quality.

Performance and Image Quality

This lens delivers usable image quality for casual photography, particularly at the short end of the zoom range (75–150 mm). At 300 mm, image sharpness declines, and chromatic aberration and reduced contrast can appear, which is common among entry-level telephoto zoom lenses. It is generally considered adequate for beginners but falls short of higher-end telephoto lenses like Canon EF 70–300mm IS or EF-S 55–250mm STM in terms of sharpness and autofocus speed.

Typical Use Cases

The lens is best for:

• Beginner wildlife photography (birds and distant subjects)

• Casual sports photography at moderate distances

• Outdoor travel shots where portability is important

• General telephoto photography on a budget

Since it lacks image stabilization, photographers may need faster shutter speeds or support systems like tripods or monopods for hand-held shooting at longer focal lengths or in low light conditions.

Compatibility and Accessories

This EF-mount lens works on all Canon EF DSLRs. On APS-C bodies, the 1.6× crop factor increases the effective focal range to 120–480 mm, making it more suitable for distant subjects. The lens has a 58 mm filter thread for UV, polarizing, or ND filters, and it comes with front and rear lens caps.

Pros and Cons

Pros:

• Affordable telephoto option

• Lightweight and portable

• Versatile focal range

• Super Spectra coatings for better contrast

Cons:

• No image stabilization

• Basic autofocus system is slower and louder

• Softness and chromatic aberration at long focal lengths

• Optical performance is modest compared to higher-end lenses

Summary

The Canon EF 75‑300mm f/4‑5.6 III is a versatile and economical telephoto zoom lens for beginners and hobbyists. It provides significant reach and portability but comes with trade-offs in optical performance and autofocus speed. It is suitable for casual wildlife, sports, and travel photography, making it a practical option for photographers entering the telephoto photography world.