canyonwalker | (Reply)

From:

Both lenses are mid-range zooms. "The Brick" was a 16-55mm f/2.8 zoom. My new lens is 15-45mm f/3.5-5.6.

Beyond the slight difference in zoom range and constant vs. variable aperture, the lenses are built to different standards. "The Brick" was built to pro standards and weighed a ton. The replacement is a kit lens and is very compact.

One feature the kit lens does have that the brick lacked is optical image stabilization. I find that more useful than the big lens's faster aperture. When I'm shooting in low light I might have my exposure as slow as 1/30 second all the way to 1/4 second. IS makes the 1/30 sec shots fairly reliable and the faster ones still worthwhile.