In an earlier post we were most impressed with how much better the new Canon 400mm f/4 IS DO II resolved compared to the original version. I mentioned that we hadn’t been able to get many copies and didn’t have time to do any other comparisons right then, but that we would do more as soon as we could.

We still haven’t gotten many copies, but we did get a little time, so I did the two comparisons that had been most requested: the 400mm DO II against Canon’s 400mm f/5.6 L and against the Canon 300mm f/2.8 IS II with 1.4x TC III.

We still haven’t received any of the other couple of dozen 400mm DO IS II lenses we’ve ordered, so the results are for the same pair as the original post. For all other lenses in this post we tested four copies and averaged the results. For the 300mm f/2.8 with 1.4X TC III test we used four lenses and four different converters. All tests are done using the same backlit film chart as the previous test, using a Canon 5D Mk III test camera.

400mm DO II vs. 300mm f/2.8 IS II

The first comparison we made was between the 400mm f/4 DO IS II and the 300mm f/2.8 IS II at their native focal lengths – 400mm and 300mm. I do want to point out that this puts testing distances at roughly 19 and 15 feet respectively. This is not ideal working distance for super telephoto lenses, so take these results with that tiny grain of salt.

We tested the 300mm lens at both f/2.8 and at f/4 to level the playing field a bit.

400mm f/4 DO II 300mm f/28 IS II f/2.8 300mm f/2.8 IS II f/4 Ctr 1490 1395 1580 Avg 1350 1220 1330 Avg Corner 1100 1100 1160

These results are about what I expected, since we already knew that the 400 DO II is really excellent. Shot at its native f/4 it has a bit better resolution than the 300 f/2.8 does shot at f/2.8. Stop the 300mm lens down to f/4, though, and it’s a bit sharper than the DO.

Could you notice these differences in a photograph? Probably if technique was equal and you pixel peep a bit. But these are all spectacular results. If you can’t tell the difference between a 300mm f/2.8 shot at f/2.8 and at f/4 (most of us can comparing side-by-side shots), then you sure can’t tell the difference between either one and the DO.

400mm Comparisons

The question most people (and by most people, I mean me and a couple of others) wanted answered was how the 400 DO compares to the 300 f/2.8 with a 1.4 X teleconverter added. Other people wanted to know how it compares with the tried-and-true, bargain-priced Canon 400mm f/5.6 L, so we did those comparisons too.

Let’s again point out that there are some differences in these tests. The 300mm f/2.8 with teleconverter is actually shooting at 420mm, so it gives a bit more reach. The 400mm f/5.6 is being compared one stop down compared to the other two, which are being shot at f/4, which gives it a bit of an optical advantage.

400mm f/4 DO II 300mm f/2.8 with 1.4X 400mm f/5.6 L Ctr 1490 1330 1390 Avg 1350 1210 1160 Avg Corner 1100 1080 990

The results, again, are fairly triumphant for the DO. The DO version I, which I shot with frequently, definitely gave up some image quality compared to a 300 f/2.8 with teleconverter. Most of us who shot the DO were willing to do so because it weighed less, and the weight was distributed near to the mount making it easier to handhold. The version II 300 f/2.8 is much lighter than its predecessor, so the weight savings isn’t quite as significant. However, it’s clear that from a resolution standpoint at least, the 400 DO is slightly better than the 300 f/2.8 IS II with teleconverter.

Again, let’s remember that with DO lenses, field tests in varied lighting conditions may well reveal other issues that a simple resolution test can’t. But the resolution test certainly suggests that shooting the DO could give results at least as good, and perhaps a tiny bit better, than the 300 f/2.8 IS II with teleconverter.

The results with the 400mm f/5.6 weren’t surprising to me at all. It has always been regarded as a very sharp lens. Given that it’s shooting at a 1-stop narrower aperture, no one should be shocked that it can hang with the other two lenses in the center. The price is certainly far more attractive, although the narrower aperture and lack of image stabilization make it a very different lens than the other two.

Would I sell my 300 f/2.8 IS II and move to the 400 DO? I doubt it. But if I was considering the two for purchase and realized I was going to shoot at 400mm, I’d be leaning towards the DO. It’s still easier to shoot handheld, the IS systems are now equal, and it doesn’t appear to give up anything from a resolution standpoint.

Can I get equivalent shots with a 400 f/5.6? If the light and technique are good, I can certainly get very close, if not equal shots. But the other two lenses will get shots in a lot of conditions that the 400 f/5.6 could not shoot well in.

Roger Cicala and Aaron Closz

Lensrentals.com

January 2015