amehta wrote:
It depends on what the lens is, how you expect to use it, and how much you saved getting the older one. OS is especially useful if you are shooting just under the "1/(focal length) s" shutter speed, as it can help keep things sharp at 2-3 stops slower shutter speed. If you are shooting at 250mm, the goal would be to use 1/250s shutter speed, but with OS you could go to 1/60s or even 1/30s. This only works if your subject is fairly stationary in the slower time frames.