Thanks, Cotty ... then, it seems (at least for me and for much of what I do) a zoom is not a replacement for primes.
This far the only zoom I've been happy with is the M24~35/3.5, but it's range is so small using it is more like adjusting framing than actually zooming. I hear what you're saying about using the zoom as a tele or long focus lens. The cat pic graphically answered my question. Perfect. This also answers a question about comparative focal lengths on a film and digi SLR. Using the 18mm on Bruce's istD didn't seem to give the same view as when using a 28mm on a film body. While the AOV may have been similar, there seemed to be a different perspective. Shel > [Original Message] > From: Cotty > > >It seems that if you are standing at a certain spot and want to fill the > >frame with the subject, you'd use the zoom feature to do so. But, is the > >perspective the same as if you used a shorter focal length prime lens and > >moved closer to the subject, assuming that in both cases the subject fills > >the frame to the same degree. > > No. This is best illustrated with examples: > > scroll down to the cats: > > <http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/2500/BASIC-OPERATIONS/ > zoom-lens.html> > > > and: > > scroll down to the cat ;-) > > <http://www.drebtips.com/digital-rebel-300D/sigma-12-24mm-lens-review/> > > > The way I use a zoom lens is perhaps ass-backwards to most : I think of > it as a telephoto lens that has the ability to 'back off' if I need to > include more of the subject in the frame. I don't own any wide zoom > lenses and can't foresee a time when I will. I have 14mm, 15mm and 20mm > wides and each is used for different things. If I want to alter the > framing with one of these, I move my butt, not a zoom ring ;-) > > HTH
