Wednesday, April 09, 2008
Playing with Macro Lens
1. Variable aperture. This was a shock to me. All my fast lenses (read: fixed aperture lenses) stay fast regardless of zoom or focus distance. So when I open my 80-200 f2.8 wide to it's max aperture of 2.8, it remains 2.8 unless I explicity change it. Not so with this baby. The max aperture is determined by "focus distance", so the closer you focus, the harder it is to achieve the stated f2.8 aperture. It's really a sort of a variable aperture lens.
2. Very painstaking to focus. This is a AF-S (silent wave motor) lens. All my previous experiences with AF-S lenses is that they focus silently and very very fast. This is not true for macro lenses. Because it's focusing range is so great, I found that the lens was hunting like crazy (very silently, of course). There is a focus-limit selector that you can set if you know the focus range is more than 0.5 meters (this limits the focusing from 0.5 meters to infinity but prevents macro focusing). The focus-limit switch speeds up the focusing a bit; but don't expect to whip up this lens and take the "candid moment" shot.
3. Shallow DOF. My 30mm f1.4 has a very shallow depth-of-field but then again, it's not a macro lens and cannot focus very close. This little baby has such a shallow DOF that even a tiny change in distance from camera to subject will throw the focus off. Observe the DOF in this tiny bottle. The DOF is limited only to a few centimeters.
Of course, none of these are limitations. They are basically features attributed to macro lenses. You just have to get adjusted to it.
This is a pretty fanstastic review of this lens.