Canon EOS-1D X + 100-400mm F5-6.3 DG OS HSM | Contemporary 017 @ 172mm, ISO 125, 1/160, f/8.0 2) Build Quality and Handling

When the wildlife is scared of you (or vice versa), 400mm permits capturing images with more-distant subjects rendered large in the frame.Above: Nikon 80-400/4.5-5.6G VR at 102mm, f5.0; 100% crop from center, APS-C/DX-corner, FF/FX-corner

Sometimes, laziness (or perhaps, "relaxation" sounds better) is a good reason to use the 100-400mm focal length range. It is often easy to create attractive, compressed perspective landscape images when using a telephoto lens. These are some of the most obscure aspects of image quality, and they are either easily corrected by a lens profile, (in the case of chromatic aberration) …or impossible, in the case of coma & astigmatism.The interior of the lens is ribbed to avoid light reflecting into the lens, and the front of the exterior is ribbed in the other direction to aid in grip during installation and removal. We’re used to seeing robust kit from Pentax with impressive build quality, and this lens is no exception. It feels particularly solid and has a durable, weather-sealed construction. The flipside is that it’s physically larger and noticeably heavier than competing lenses, weighing in at 2kg. That’s nearly twice the weight of the Sigma and Tamron 100-400mm lenses, although they’re only available in Canon and Nikon mount options. There are also a set of in-camera aberration corrections available with current and recent Canon and Nikon bodies, curbing peripheral illumination, distortion and lateral chromatic aberration.

Telephoto lenses are extremely popular, and manufacturers have created many options to capture that demand.The replacement AF-S lens has typically fast and near-silent ring-type ultrasonic autofocus, that works with any Nikon DSLR or mirrorless Z-series camera. Furthermore, it has Nikon’s old-style aperture control lever, rather than an electromagnetic system (as featured in the Sigma and Tamron lenses), ensuring compatibility with older Nikon DSLRs. Smaller birds and animals often need longer focal lengths to have a substantial size in the frame, and these are included in the great subjects list for such a telephoto lens. Again this lens performs well across its zoom-range in this long distance test. If you want to see all the details, read on. Or fast-forward to the next chapter on rendering of point-light sources at night-shots. This results in full use of your camera's imaging sensor, which in turn (potentially) results in better overall image quality.