What to look for…

REAP THE BENEFITS OF a fistful of feat ures with your ne xt te le-zoom Internal focus

Thanks to internal focusing, the front element doesn’t rotate in any of the lenses on test, making circular polarizer and ND grad filters easier to use.

Autofocus mechanism

All of the lenses on test feature ring-type ultrasonic autofocus systems with full-time manual override, apart from the older of the two Tamron 70-200mm lenses.

Internal zoom

A bonus of the internal zoom mechanism featured in all the lenses on test is that the physical length doesn’t extend at longer zoom settings.

Optical stabilizer

The Sigma 50-100mm and non-VC Tamron 70-200mm lenses are the only lenses in the group to lack optical stabilization.

Jargon buster Constant-aperture

In a ‘constant-aperture’ zoom lens, the widest available aperture remains fixed throughout the entire zoom range, rather than shrinking at longer zoom settings.

Internal focus

With fully internal-focus designs, the large front element remains fixed. Movement of the smaller rear or mid-section elements enables faster autofocus performance.

Aperture rating

All lenses in the group have an f/2.8 aperture rating, apart from the slower Nikon 70-200mm f/4 and faster Sigma 50-100mm f/1.8.

Weather-sealed mount

Most lenses have a rubber weatherseal on their mounting plate, apart from the Sigma 50-100mm and 70-200mm lenses, and the older Tamron 70-200mm.