I've been shooting with a Canon EF 100-400mm IS USM "II" lens for a couple years.... most often on APS-C cameras (7D Mark II). I've been very happy with the lens' image quality, focus speed, stabilization and close focusing capabilities. I've also heard that it works very well with a quality 1.4X teleconverter, but had never really put it to a test, even though I've had Canon EF 1.4X II and 2X II Extenders for many years. I just never had a shooting situation that called for increasing the focal length of the lens (in large part because of the "free 1.6X teleconverter" effect of the APS-C cameras I was using it upon.
Immediately below is a shot of a Kildeer done with the lens alone -
without any teleconverter - near it's closest focus distance and on the same APS-C camera used yesterday...
I've been happy with the lens alone, but have continued to hear and read positive comments about using it with a TC.
Yesterday I was outside and noticed the waxwings were busily gulping down berries from several trees. So I decided to get out the lens and camera to take a few shots and see how the 100-400 II and 1.4X worked together. I used my car as a "blind". Even so, I was only 12 to 18 feet from the subjects and they knew I was there. Very fast little birds that were quick to take off if I moved too fast or made too much noise, it took an hour or so and lot of attempts to get a few shots I was happy with. But when everything "clicked" (especially me getting focus, composition and timing right), I'm pretty impressed with the results the lens & TC produced.
Below are a couple finished images from the 240 RAW I took yesterday with the lens and teleconverter combination.
The first is done with the lens zoomed to the shorter end and about 300mm... The second uses it "racked out" as far as it would go, all the way to 560mm (I'm not applying the crop-sensor lens factors.... the cited numbers are the actual focal lengths of the lens/TC combo).
The first image is rather heavily cropped (from 3:2 horizontal to 5:4 vertical). The second image has very little cropping.
Some adjustment, NR and selective sharpening were done to both images (Lightroom & Photoshop).
Please be sure to click through to the larger versions.... For some reason the previews I see here seem a bit desaturated, but the larger versions look correct on my calibrated monitor.
I've been shooting with a Canon EF 100-400mm IS US... (