Field-Testing the Sony 100-400mm f/4.5-5.6 GM OSS Lens - 05 Feb 2019

As THE potential replacement for the Nikon D500 / Nikon 300mm f/2.8 VRII I had the chance to take the Sony FE 100-400mm f/4.5-5.6 GM OSS lens for a spin on the Sony a7III down here on the Detroit River in Wyandotte. At almost half the size and weight of the beloved 300/2.8 VRII the lens felt surprisingly light and tiny despite user comments mentioning its "weight". It's all perspective though, as anyone who's ever handled a big prime from Nikon or Canon will attest to, the Sony 100-400 feels light in my hands.

I won't spend any time reviewing the lens specifications, as many, better photographers have provided nice reviews that include all of this information. I will just reiterate how tiny it feels in my hands. Skies were overcast but temps were relatively mild enough to not need gloves as I walked the river at Dingell Park in Ecorse at noon. The river ice had opened up a bit, and the Canvasbacks were not hugging the shoreline like they had the past several days, but enough of them were close enough to give me something relatively close up to photograph. I'd also be testing the Action settings of the Sony a7III so I'll comment on them, as well.

I stopped by the Seaway Boat Club and spent a few minutes trying the camera / lens on the Canvasbacks swimming near shore. The a7III was set up for Aperture-Priority, f/8, ISO Auto (100-12,800) with a minimum shutter speed of 1/1000 sec. Focus Area was set to Lock-On AF: Flexible Spot M - this allows auto-focus to lock onto its subject and track it as long as the subject stays in the viewfinder. I was quickly impressed how well this feature worked when I took my first flight shot of a Canvasback flying past me. The focus boxes flashed green on the head of the duck and stayed locked on its head as I panned to keep up with its flight. I should've shot at 1/2000 sec to freeze wingbeats but focus was spot-on! It was plenty fast to get the fly-by Herring Gulls.

I then drove down to Dingell Park to see if any photo-pops were presenting. The south end of the pier was quiet, so I took a few pics of the Canada Geese and trees as I walked toward the north end.  The bokeh on this lens is sweet!

At the north end of the park I had the opportunity to photograph a few Lesser Scaup, as well as the resident Mallard that were quietly sleeping on the ice next to shore. The detail captured by this lens was quite impressive; I expected to have to provide a bit of extra sharpening in post-process (compared to the Nikon 300/2.8 VRII) but was happy to discover that many images needed no extra sharpening. The image quality from this Sony a7III is AMAZING!

Back at the boat club I spent a few last minutes shooting some of the Canvasback and Mute Swans that were continuing their shad-fest. Once again the camera and lens did a remarkable job of locking focus and tracking subjects despite the relatively low light.

From the many reviews I read of the Sony 100-400mm f/4.5-5.6 GM OSS an issue that plagues the lens is chromatic aberration (CA). I fully-expected to have to make adjustments in Lightroom, especially on pics of high-contrast areas, like the scaup below. Of the almost 1000 photos I took this day not one needed any CA correction. Additional happy points!

To call this 30-minute outing a success is understating the experience. I absolutely LOVE this combo! Not only were all photos at 400mm sharp, but all photos with the 1.4X TC attached, and the APS-C Crop Mode engaged at 400mm were sharp, as well! This 100-400mm lens has exceeded my expectations in every aspect: size, weight, handling, and image quality.

I leave my review with one last pic, and the promise to bump up the minimum SS next time I'm out.

I wish to thank the Front Office for permission to purchase this lens, and the good folks at Pro Cam in Livonia for making my drive to their store worth the time and expense. 

Hello, Sony!