"David J Taylor" wrote in message
...

"Dudley Hanks" wrote in message
news:7waMn.5161$Z6.1914@edtnps82...
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I was wondering when somebody would point that out...

My only lenses for the XSi are either 3.5 - 5.6 or 4.0 - 5.6, so the
f/2.8 - 4.3 is still larger, even at long focal lengths...

The aperture (as an f/number) may be slightly "smaller" (i.e. higher
f/number), but more light is collected because the actual physical
aperture is greater (i.e. more photons get in).

As for the ISO 3200 not producing the full resolution, that would only be
a problem if I intended to produce low light, large format prints, which
I obviously would not, and the image size is plenty big enough for posts
to Usenet, my site, etc...

Of course, but applying the same resolution reduction, the DSLR will work
as well at 6400 12800 etc. ISO.

I forgot to put the smaller end of the aperture range, as I do not shoot
at full zoom very often. Most of my pics are at the shorter to mid focal
length of the 36 to 360mm lens. So, even at 3.5 for about 180mm, the
aperture is as large as the lowend of my other lenses, which seems like a
large aperture zoom to me...

Take Care,
Dudley

Normally, I have similar lenses to you (16-85mm, f/3.5-f/5.6; 70-300mm,
f/4.5-f/5.6), but I treated myself to an f/1.8 lens for my DSLR recently.
The f/1.8 combined with the ISO 3200 allowed me some shots of the aurora
borealis, with which I was very pleased. For low-light and night-time
shots, I would be in envy of the full-frame DSLR and f/1.4 lenses! G

Cheers,
David

You and me both ...

My next lens will probably be either a macro (not sure which one) or the
f/2.8 85mm lens. With my old A1 camera, I had a nice 130mm lens which was
great for portraits, candids, etc, and I think the 85mm will yield similar
results with the XSi.

Take Care,
Dudley