Zoom lens for Canon 300D - Tamron/Canon

In message ,
MarkH wrote:

wrote in :

In message ,
Jim Townsend wrote:

It's not a bad little lens. It isn't as sharp as my EF 100-400 L, but
the color and contrast is about the same. What I really don't like
about it is that it's *very* prone to purple fringing.

Purple fringing is a sensor problem. Do you mean chromatic
aberration?

What's the difference? Is the definition of chromatic aberration different
in your dictionary? (Purple fringing is an aberration of the chroma as far
as I know)

It's not an aberration. It is electrons from saturated green-filtered
sensors spilling into the surrounding blue- and red-filtered sensors.
It is only purple because the demosaicing algorithm thinks it's real red
and blue light.
--


John P Sheehy

wrote in :

In message ,
MarkH wrote:

wrote in :

In message ,
Jim Townsend wrote:

It's not a bad little lens. It isn't as sharp as my EF 100-400 L,
but the color and contrast is about the same. What I really don't
like about it is that it's *very* prone to purple fringing.

Purple fringing is a sensor problem. Do you mean chromatic
aberration?

What's the difference? Is the definition of chromatic aberration
different in your dictionary? (Purple fringing is an aberration of the
chroma as far as I know)

It's not an aberration. It is electrons from saturated green-filtered
sensors spilling into the surrounding blue- and red-filtered sensors.
It is only purple because the demosaicing algorithm thinks it's real
red and blue light.

This is fascinating, I have never heard of this before. Could you provide
some links to info on this problem and why it happens? I really would like
to read up more on this.



--
Mark Heyes (New Zealand)
See my pics at www.gigatech.co.nz (last updated 12-Nov-04)
"There are 10 types of people, those that
understand binary and those that don't"

Eric Gill wrote:
That's extremely bad advice. Lenses are good or bad depending on
their
design, features, and build, not the logo stamped on them.

Yep, I have my eye on the Tamron 17-35mm f/2.8-4. At $450, it looks
very tempting.


Yes, it's not made as well as the 24-70L. It doesn't focus as fast.
It's
not weather sealed. It was also just $350 instead of over a thousand
bucks,
a compromise I was very happy to make. Would everyone? No - but you
select
what you pay based on the features set, not the name.

Ahhh!! you can't compare with a $1000++ "L" lens. Simply not fair



As for Siddhartha's question, I own a 75-300IS and cannot reccomend
it
except as a budget lens you'll replace sometime soon. The glass is
mediocre, the USM is adequate at best. The construction is cheap,
it's a
very elongating push-pull design and the IS helps but is no
substitute for
fast glass. Unfortunately, I have no experience with the other lenses
you
are looking at, but it certainly does seem that the 28-300 is not
well
regarded.

I think I'll get the Canon 100-300mm f/4.5-5.6. When I have more money
(maybe in a couple of years), I'll probably get the 100-400mm "L". But
the build quality of the 100-300mm looks like its well worth keeping
even then. The features it has over the 75-300mm USM a
- Ring-USM (aka true USM) hence faster AF and MF over-ride
- Rear-focussing elememt
- Metal mount (polycarbonate body)
- distance window

Optically, no one seems to put it WAY above the 75-300mm but maybe just
a notch above.

Thanks for the replies.

- Siddhartha

"Siddhartha Jain" wrote in
oups.com:

Eric Gill wrote:
That's extremely bad advice. Lenses are good or bad depending on
their
design, features, and build, not the logo stamped on them.

Yep, I have my eye on the Tamron 17-35mm f/2.8-4. At $450, it looks
very tempting.

Allegedly great for the money. I splurged for the Canon L version (ouch!),
so am very spoiled here. Having a constant f-stop is a wonderful thing.

snip

Ahhh!! you can't compare with a $1000++ "L" lens. Simply not fair

Ten to one I break down and buy the "L" - in about a year or so, when I'll
hopefully be shooting even more than now. In the meantime, I got some great
glass, my wife got a shopping spree, and there was money left over, thus
helping to ensure I'll still be married a year from now.

Canon 100-300mm f/4.5-5.6.

Optically, no one seems to put it WAY above the 75-300mm but maybe just
a notch above.

Well, it seems you have to bring a great pile of cash to the table for a
better zoom in the 300+ range. On paper (never used it) all the features
you list plus the low price makes it sound like the best choice available.

Thanks for the replies.

You bet.