Aperture vs IS canon lenses

[rcheshire]

Any thoughts on the Canon 24-70 f/2.8 L USM vs 24-105 f/4 L IS USM. Thinking about the options, f/4 with IS gives an additional 3 stops at lower shutter speeds, which equates to f/2.8 (I think). Is that a rational way of looking at the problem - f/2.8 with IS would be ideal.
I would like the aperture, but really like IS. Optically, these are good lenses as I understand it.

[Octane]

Three stops faster than f/4 is f/1.4.

The better way to think of it is that if a shot requires 1/240s at 0EV, with IS enabled, you could get away (potentially) with the same shot in 3EV at 1/30s.

The 24-105mm f/4L IS USM practically lived on my camera for eons. It's only been replaced with the 70-200mm f/2.8L USM as there's no room in the bag for the 70-200mm other than on the body. :)

http://users.tpg.com.au/octane2/shoot1.html

All shot with the 24-105mm f/4L IS USM and straight out of DPP.

H

[rcheshire]

Thanks H. That settles it. The 70 - 105 fills the gap well. f/1.4:thanx: Great images. The monochromes seem to be a specialty of yours...

[koputai]

Rowland, you have a crop sensor camera don't you? You should
also consider the EF-S 17-55 f/2.8 IS. It's not an L lens as such, but
it is a VERY good lens, and extraordiarily versatile.

Cheers,
Jason.

[rcheshire]

Thanks Jason. I did look at the 17-55 and was tempted to go that way, except that I use an Astronomik clip filter - eventually, I will upgrade the body also.