What’s New. Technology has changed since the original Canon 100-400mm f/4.5-5.6L IS was released in 1998. This new version offers improved optics, focusing, stabilization, hood design, tripod ring design, zoom method, and…if you’re noticing a trend, everything is new, all to provide better image quality and performance.

Long-Range Zoom. Like the original, you’re still getting a focal range of 100-400mm; however, everyone’s prayers have been answered and the push/pull zoom method (a.k.a. the internal dust vacuum) has been replaced with standard rotational zoom. Interestingly, Canon left in the zoom tension ring. You know, for those times you need to tighten a rotational ring with a second rotational ring.

4-Stop Image Stabilization. Compared to the former’s 1.5 stops of correction, you’ll now be able to keep shooting while you’re running from the bear you disturbed. It’s auto-tripod sensing, so you can just set it and leave it. There are three modes: normal, panning, and “I like to see a shaky image in the viewfinder but want it to be stabilized in the shot.”

Ultrasonic Motor. The Canon 100-400mm II has an updated internal focusing system with a high-speed CPU and optimized AF algorithms that provide faster, near silent performance. It’s also worth noting that the minimum focus distance has been reduced to just 3.2 ft with a magnification of 0.31x (down from 5.9 ft/0.20x on the original).

Optics. This all-new formula of 16 groups/21 elements includes one fluorite element and one Super UD (Ultra Low Dispersion) element to combat chromatic aberrations throughout the zoom range. Fluorine coatings on the front and rear elements help resist moisture, dust, and fingerprints. But that’s not all! Canon has included an Air Sphere Coating (ASC) to help reduce backlit flaring and ghosting while retaining contrast. What’s an Air Sphere Coating you ask? Well, it’s tiny air bubbles, and I’ll leave it at that.

Build. The weather-resistant magnesium housing of the the Canon 100-400mm f/4.5-5.6L IS II promises professionals a workhorse to update their previous generation workhorse. Despite the removal of the dust-vacuum zoom method, please be aware that the Mark II is still larger and heavier. The redesigned hood now includes a side window for adjusting rotational filters like CPs and variable NDs, while the new rotating tripod ring has a removable foot that allows it to be detached from the lens without having to dismount the lens.