Nikon 24-70 f/2.8 or Nikon 24-85 f/3.5-4.5 VR ?

The 24~70 has a wider aperture and is good wide open too so it is a better choice in poor light or if you want shallow DoF. The 24~85 has VR but that doesn't help with anything that moves, e.g. people. The 24~70 is pretty good close-up too. The downsides are the extra cost and weight, but you get what you pay for.

Personally I use the 24~120 f4 for walkabout and events and that;s the only zoom I have in this range but I also own some fast primes when I want a wide aperture (and less distortion). If I never owned the primes I would own the 24~70 instead, but ideally I would also want something longer for portrait.

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www.andrewsandersphotography.co.uk