Buying guide
f/2.8 or f/4 zoom: which should you buy?
What one stop of light really gets you, what it costs in size, weight and money, and which pairs of zooms to compare.
Shutterswoop · Updated 26 October 2026
The short answer
An f/2.8 zoom lets in twice the light of an f/4 one and blurs backgrounds more, which matters indoors, at events and after dark. An f/4 zoom is lighter, much cheaper and often covers a longer range, and with today's cameras it's plenty for travel and daylight. Buying used makes the f/2.8 option far more affordable.
What one stop gets you
f/2.8 is one "stop" brighter than f/4: the opening lets in twice as much light. In the same light you can use a shutter speed twice as fast (sharper pictures of moving people) or half the ISO (less grain). The wider opening also gives a shallower depth of field, so backgrounds blur more.
It isn't magic: one stop is noticeable, not transformative. Many modern cameras handle high ISO well, and stabilisation helps with still subjects, though not with moving ones.
Side by side
| f/2.8 zoom | f/4 zoom | |
|---|---|---|
| Light | Twice as much | Half as much |
| Background blur | More | Less |
| Size and weight | Bigger and heavier | Smaller and lighter |
| Price | Much higher | Much lower |
| Range (standard zooms) | Usually 24-70mm | Often 24-105mm |
| Best for | Weddings, events, indoor sport, low light | Travel, landscapes, daylight, video on a gimbal |
Which should you buy?
Choose f/2.8 if
- You shoot people indoors or after dark, where moving subjects need fast shutter speeds.
- You want blurrier backgrounds without carrying primes.
- You get paid for it: weddings and events are where f/2.8 earns its keep.
Choose f/4 if
- You mostly shoot outdoors in daylight, travel or landscapes (often at f/8 anyway).
- Weight matters: you'll carry it more, so you'll use it more.
- You want the extra reach of a 24-105mm, or to spend the savings on a fast prime.
Pairs to compare
- Sony standard zoomSony FE 24-70mm F2.8 GM II or Sony FE 24-105mm F4 G OSS
- Sony telephoto zoomSony FE 70-200mm F2.8 GM OSS II or Sony FE 70-200mm F4 Macro G OSS II
- Canon standard zoomCanon RF 24-70mm F2.8 L IS USM or Canon RF 24-105mm F4 L IS USM
- Canon telephoto zoomCanon RF 70-200mm F2.8 L IS USM or Canon RF 70-200mm F4 L IS USM