When Nikon first announced the D4, I’ll admit that there weren’t a ton of features in the spec sheet that really made me jump up out of my chair. Most of the new features are subtle, unless you are a professional videographer (the D4 video options are top-notch). In my original post reacting to the D4 announcement, I mentioned several items that were of potentially great use to outdoor/wildlife photographers, and two of these made me want to upgrade over the D3s:
- Better AF, and the ability to autofocus with teleconverters up to at least f/8
- More pixels for using 1.2x crop mode (or just cropping)
As a Nikon shooter, I have a tough decision when I want to photograph birds. Currently, the Nikon D300s is the only DX body with performance features anywhere close to the D3 or D4. Sadly, the D300s is nowhere near as good at high ISO shooting (something that you frequently need with big glass) as the D3s and D4 cameras. It’s not that the D300s is a poor-performer (it’s excellent), but the D3/D3s/D4 bodies are just that much better at high-ISO shooting. They are also slightly more responsive cameras than the D300s.
The conundrum, of course, is focal length choice. Using a DX body for bird photography is quite rewarding; the crop factor lets you get really close. With a FX body like the D3s or D4, you need to use a longer lens, a teleconverter, or both to get the same magnification as you’d get from a DX body. That’s why the D4 gains a big advantage over the D3 for wildlife; it can focus with more powerful teleconverters. Most big lenses have a maximum aperture of f/4 (200-400mm, 500mm, & 600mm Nikkors). Add a 1.4x teleconverter, and you’re at f/5.6, which is the in-spec limit for Nikon AF systems prior to the D4. Although I own the Nikon TC-17EII (1.7x) and TC-20EIII (2x) converters, I rarely used them with my f/4 glass because the light needed to be very good to get any kind of autofocus at all. Usually, the focus lock was slow, and tracking was not feasible with anything other than the TC-14E converter.
I went out to a local nature preserve with my 600mm f/4 AFS G VR Nikkor, and the TC-14E and TC-17EII converters. I was very pleased with the results. AF was very fast to lock-on, and it tracked well with both converters. Anytime you get into a situation where you have 1000+ mm of focal length, even small focus errors will be noticeable. With small birds, you’re pushing any focus system to its limits. Needless to say, I’ll be bringing the D4 down to Texas for my birding photo workshop; I expect it to perform very well.