Should I buy a used Sony FE 24-105mm or Tamron 28-75mm?

Deciding between a used Sony FE 24-105mm f/4 G OSS and a used Tamron 28-75mm f/2.8 depends on what you value more: focal range versatility or low-light performance.

When to buy the Sony FE 24-105mm f/4 G OSS:

• You need maximum versatility: The 24-105mm range is incredibly useful. The 24mm wide end is significantly wider than 28mm for landscapes, architecture, and tight indoor spaces, while the 105mm long end gives you real telephoto reach.
• You shoot outdoors and travel: It functions as a true "one-lens" solution, reducing the need to swap lenses on the go.
• You need lens stabilization: It features built-in Optical SteadyShot (OSS), which is highly beneficial if you shoot on older Sony bodies without in-body image stabilization (IBIS) or want extra stability at the telephoto end.

When to buy the Tamron 28-75mm f/2.8:

• You shoot in low light or want background blur: The constant f/2.8 aperture lets in twice as much light as an f/4 lens. This allows for lower ISOs in dark environments and produces a shallower depth of field with softer background bokeh for portraits.
• You want the sharpest center performance: The Tamron consistently outperforms the Sony in center sharpness, even when shot wide open at f/2.8.
• You prefer a lighter, more budget-friendly setup: It is physically lighter to carry all day and generally costs less on the used market than the Sony G-series lens.

Summary Recommendation

If you primarily shoot landscapes, travel, and daytime outdoor scenes, choose the Sony 24-105mm f/4. If you prefer portraits, events, indoor low-light shooting, or want a lighter walk-around lens, go with the Tamron 28-75mm f/2.8.