09-23-2011, 08:49 PM
As a general-purpose zoom lens? Then definitely the 15-85 on a crop-sensor camera.
The 24-105 is a very nice lens, but the difference between 15 and 24mm on the wide end is huge.
And besides, the 15-85 is basically Canon's equivalent to the 24-105 for APS-C (the same way the 17-55 is meant as an APS-C equivalent to the 24-70).
[size="1"](Yes, they're not exactly equivalent to their FF counterparts from a technical point of view, but they serve the same purpose on each camera system)[/size]
Of course, you can use the lenses any way you want. There's nothing wrong about using a 24-105 on a crop-sensor camera, but the resulting 38-168mm range is probably not for everyone.
After all, there is a reason someone thought that it would be a good idea to start standard-zooms at 24mm (or 15mm in case of APS-C). It's just very convinient.
The 24-105 is a very nice lens, but the difference between 15 and 24mm on the wide end is huge.
And besides, the 15-85 is basically Canon's equivalent to the 24-105 for APS-C (the same way the 17-55 is meant as an APS-C equivalent to the 24-70).
[size="1"](Yes, they're not exactly equivalent to their FF counterparts from a technical point of view, but they serve the same purpose on each camera system)[/size]
Of course, you can use the lenses any way you want. There's nothing wrong about using a 24-105 on a crop-sensor camera, but the resulting 38-168mm range is probably not for everyone.
After all, there is a reason someone thought that it would be a good idea to start standard-zooms at 24mm (or 15mm in case of APS-C). It's just very convinient.