switch from a 24-70 to a 24-105?

Is the addition of IS (I can't hold a camera still for squat anymore) worth the reduction from 2.8 to 4?

I shoot outdoors far more than inside and I usually stop down a bit to increase sharpness. So, I'm thinking I won't miss the f/2.8. How much does the 24-105 f/4 have to be stopped down to increase sharpness?

I shoot the 24-105 anywhere from f/4 to f/16 and don't have any problems with sharpness at all. I wouldn't have any qualms about making the switch. But the IS and extended reach are much more important to my shooting than the f/2.8 would be....YMMV

If you can't hold still anymore then the IS should help for non-moving subjects and it could be a good switch for you. The IS giving better than the 1 stop in aperture for non-moving subject. With the added benefit of a greater range in FL.

If you shoot mainly active subjects, then maybe learning to use flash effectively would be a better solution than a lens with IS.

24-105 is an excellent lens! I just recently sold it for the 24-70 II after years. Always excellent results. Very versatile.

The beauty of good lenses is resale. They hold their value better than cars or electronics. As long as we keep them in like new shape.
Ho wmuch do you want for your 24-70?

mine is sharp wide open

Snydremark wrote in post #15076462
.... the IS and extended reach are much more important to my shooting than the f/2.8 would be....

my sentiments exactly

Snydremark wrote in post #15076462
I shoot the 24-105 anywhere from f/4 to f/16 and don't have any problems with sharpness at all. I wouldn't have any qualms about making the switch. But the IS and extended reach are much more important to my shooting than the f/2.8 would be....YMMV

Which can easily be worked around with by using higher shutter speeds, and for range- in most cases, your feet. You can not substitute aperture. I would stick with 24-70. But again, that's your shooting needs so it may be more suitable.

ZeroSkylineX wrote in post #15077151
Which can easily be worked around with by using higher shutter speeds, and for range- in most cases, your feet. You can not substitute aperture. I would stick with 24-70. But again, that's your shooting needs so it may be more suitable.

There isn't always enough light for higher shutter speeds, and "foot zooming" can mess with perspective or be impossible due to any number of barriers, etc; especially outdoors in an uncontrolled environment. So, you can't really substitute a large aperture for those things, either. IS can let you shoot slower shutters at lower ISOs than just using a larger aperture can, too.

No, one, item out of that list is a full substitute for the other; but, that's why figuring out individual needs is important before buying a lens.