Me writes:

On 19/09/2012 1:12 p.m., Robert Coe wrote:
On Tue, 18 Sep 2012 15:23:11 +1200, Me wrote:
: I think the new OS 50-150 is quite a bit heavier than the older non OS
: version you have, hence most of my negative comments.
: Yes - Sigma make a 70-200 f2.8 OS, less than 100g heavier than the OS
: 50-150, and about $1250 street price. It's probably okay.
: I'm not a Canon owner. There are two things in Canon land that I really
: envy. One is the 17mm TSE, the other is the 70-200 f4 L IS. The latter
: is what you should be getting your wife for Xmas. I have used that lens,
: and it's an absolute gem (on 5D and 5DII bodies). In fact I'd go so far
: as to say that if I decided to buy a Canon body, I'd buy the darned lens
: first, then cart it around camera stores to decide which body suited it
: best.

Why do you prefer the f/4 to the f/2.8? Because it's lighter? The 70-200 I
have is the f/2.8L IS II, and it's plenty sharp for my eyes. But it is heavy,
and I seldom carry it outdoors for that reason. I consider it mainly an indoor
event lens, and it's hard to beat in that role (although maybe a bit long for
my 7D's).

Yes - because it's lighter, much less expensive, and darned
good. Perhaps check exif on files you've taken using the f2.8, even
indoors, and see how often you actually use it fully wide.

I'm guess quite possibly less than 50% of the time. On the other hand,
I resort to fast lenses when it's dark.

The concept of deliberately getting a zoom I plan to use a lot slower
than f/2.8 is kind of appalling to me, I admit. That's *already*
sacrificing a lot of speed by my standards.

Depends what you shoot, of course.
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