Lens review

Canon EF 400 mm f/4 DO IS II USM

26 August 2017
Maciej Latałło

10. Autofocus

The autofocus of the tested lens cooperating with the EOS 5D Mark III is silent and very quick. Running through the whole distance scale and finding the right focus position takes about 0.3-0.4 of a second. It’s so fast that you really don’t have to use the focus limiter to speed the process up (but, of course, it doesn’t mean the limiter is useless). With the 1.4x (TC1.4x III) teleconverter the focusing time increases very slightly; still then the chances are that the mechanism might get a bit lost. Those chances are bigger after attaching the 2.0x teleconverter (TC2.0x III) although the focus speed remains similar. It also should be noticed that in the latter case you get just the central AF point at your disposal.

A bit more reservations we have when it comes to the cooperation with the EOS 80D camera. With just the lens attached, there are almost no problems at all. Adding the 1.4x teleconverter, though, makes the chances of autofocus play increase significantly, especially if the scenes are not especially contrasted. In the case of the 2.0x converter those problems are practically guaranteed. It often happens that the autofocus moves from one end to the other and can’t find the proper position. Employing the limiter is a great help, providing that you can use it which in some situations might be impossible. For example, the value of 8 meters is quite crucial in bird photography; small birds usually appear in a distance of 5-10 meters of your field of view . Not knowing where the bird is going to sit you can’t limit the focusing range. That problem doesn’t exist with plane or sport photography, where setting the range from 8 meters to infinity is always a good choice.

If you take photos on full frame and without any converter the minimum focusing distance might be a drag as it amounts to 3.3 meters. During the tests it happened several times that my photographic object was closer and I had to take a step back to enable the lens to set the focus. It’s worth reminding here that the EF 400 mm f/2.8 L IS II USM is able to focus from 2.7 metres and such models as the EF 300 mm f/2.8 L IS II USM or the EF 200-400 mm f/4 L IS USM EXT. 1.4x – already from 2 meters.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

The tested lens didn’t have any problems with front or back focus. It didn’t miss, no matter what bodies it was attached to, with or without the TC1.4x or the TC2.0x teleconverters.

Canon 80D, f/4.0
Canon EF 400 mm f/4 DO IS II USM - Autofocus
Canon 5D MkIII, f/4.0
Canon EF 400 mm f/4 DO IS II USM - Autofocus
Canon 80D, TC1.4x, f/5.6
Canon EF 400 mm f/4 DO IS II USM - Autofocus
Canon 5D MkIII, TC1.4x, f/5.6
Canon EF 400 mm f/4 DO IS II USM - Autofocus