[mickeymax]

I have a quick and probably basic question. Do prime lenses focus a lot faster than zoom lenses?

[Markulous]

I suppose the answer is probably yes and no:
No, there's no particular technical reason why a prime should focus faster than a zoom
except
Yes, given that primes have a greater aperture they tend to focus easier, if not faster (most SLRs will struggle when the max aperture is f/8 as it becomes too dark to measure the contrast - the result can be 'hunting' back and forth)

[Rob Barron]

Mark's hit the nail on the head there. AF systems like having more light to play with and that accounts for why high end lenses with wider apertures tend to be faster than others. But as a difference between prime and zoom, there isn't a huge difference when talking same focal length and aperture. Not saying a prime might not be very slightly faster but you're talking such small as makes no difference.

Cheers,
Rob

[JMitchell]

Also in zooms, more glass elements to move further when going from one end of the focus range to the other....so more likely to be slower.

[mickeymax]

ok that makes sense thanks. That would mean that the 50mm f1.8 would focus quicker than the 75-300 because of the wider aperture.
Thanks

[muscle750]

My 85 1.8 Nikon renders colours far better than my 18 200 at 85mm, one of the best lenses i got.