Originally posted by dugrant153 Autofocus is slow, but as I learned this weekend... if there's no light or it's very dim for the lens to focus, even the DA40 will take a long time to focus. Soooo... I'm going to go against the grain and say the autofocus speed is not too bad. Definitely usable in almost all circumstances.
+1 on this.
For those of you considering this lens as a possible normal or "walkabout" lens and concerned about AF speed, allow me to clarify what's going on here. The focus ring rotates a total of about 160 degrees from infinity to the minimum focus distance of 13.9cm. However, the focus ring rotates less than 10 degrees from infinity to 2 feet (60cm). You can see this for yourself in the numerous product shots of this lens on the web. For comparison, my FA 77mm Limited's focus ring rotates about 160 degrees to go from infinity to 70cm and is an absolute dog in terms of AF speed.
So, while it is true that a full rack from infinity to the minimum focus distance can be a time consuming (and noisy) affair, the AF speed at normal shooting distances is BLINDINGLY quick (assuming that the lighting is good enough for the camera to AF effectively). In fact, on my K10D, I find that the focus speed is limited more by the camera's AF algorithms double-checking the focus accuracy than by the mechanical design of the lens itself. Solution? Same as every other lens: set the AF mode to AF-C, and release the shutter after the first or second AF "movement". Also, consider switching off SR, because shooting with SR "enabled", but not "ready" can actually introduce blurring due to the movement of the sensor.
Bottom line: The focus speed you are able to achieve when using the DA35 macro limited at regular shooting distances is limited more by the camera's AF system and settings, than by the lens design or its status as a "macro" lens.
PS: As with all lenses having a short AF throw, there is a trade-off for this fast-focussing ability - manual focussing accurately is almost impossible at regular shooting distances. Fortunately, at macro distances (where you're most likely to actually use MF), it's a breeze to focus manually. Also, using manual hyperfocal techniques (e.g. for landscape photography) are next to impossible - just look at the DOF scale (F22 can't even get from infinity down to the 2 feet, which is the first distance marking on the focus scale).