View Single Post
  #14  
Old June 29th 04, 08:37 PM
David Littlewood
external usenet poster
 
Posts: n/a
Default "Normal" Canon Zoom Lens that's worth a damn?

In article , Karl
Winkler writes
David Littlewood wrote in message
.. .
In article , Karl
Winkler writes

What part of having high quality optics at reasonable price and actually
moving instead of zooming is counterintuitive?

Perspective. Moving does not replace the ability to control
perspective.

Moving is the only way to control perspective, apart from using a
tilt/shift lens. Zooming alone can only change magnification, and leaves
perspective absolutely unaltered.


I understand what you're saying but perhaps I'm not getting my point
across very well. Here's what I mean: let's say I want to take a
series of portraits of someone. With a medium-range zoom, I can
accomplish everything I need. Full length portraits can be done at the
shorter end of the range or perhaps somewhere in the middle (~40 to
50mm on a 35mm body) and then tighter head shots can be done at the
longer end (70 to 105 or even 135mm). If I used a 50mm lens, I can do
the full-length portraits but it will not work to "move closer" to do
the head shots.

In this specific case, I could also use two fixed-length lenses (say,
50mm and 100mm), but what about the focal lengths between those two?

And changing focal lengths (via zoom or by changing lenses) changes
the *angle of view* of the lens, say from 90 degrees at 20mm to 60
degrees at 50mm to 30 degrees at 90mm (approximately), right? So to
me, this is changing the perspective.


Not in the normally-accepted use of the word in photography. You would
get exactly the same result (apart perhaps from more grain) by using a
wide and blowing up the central portion as using a long lens.

With longer lenses, there is
more foreshortening (distant objects seem closer or more "compressed")
while shorter lenses do the opposite. And to me, these are important
considerations.


Only because you usually use a long lens from a long distance, and a
wide from very close. If you use a long lens very close up you get the
same perspective as with a wide, just less angle of view. Same if you
use a wide from a mile away and blow up - very "foreshortened"
appearance just as when using a tele from the same spot.

Heck, a zoom lens lets you do all three things:

1. Alter the angle of view and/or foreshortening effect, and
2. Move closer or further away if you want to, and
3. Allow you to do all of these things without changing lenses


True.

You have no argument from me that good prime lenses are (generally)
superior optically. But considering the versitility of zooms and the
fact that some of the current designs (Canon L series, for example)
are very, very good, I think it's why it is becoming far more common
to see photographers with a range of 2 or 3 zooms than 6 different
prime lenses.

True; it was only the understanding of "perspective" that I was raising.

David
--
David Littlewood