Sigma highlights another problem with plastics, thermal change
 

In article
,
RichA wrote:

Heat expansion and contraction, which effects optical performance. So
they've introduced something else to compensate for it. Because
aluminum and magnesium don't suffer nearly as much thermally-related
shape changes as plastic, older lenses and new high-end principally
metal lenses do not have the problem.

Sigma's biggest problem is their lying about the crappy technology used
in their overpriced, mediocre equipment.

Sigma highlights another problem with plastics, thermal change
 

On 2012-06-17 11:46 , Mr. Strat wrote:
In article
,
RichA wrote:

Heat expansion and contraction, which effects optical performance. So
they've introduced something else to compensate for it. Because
aluminum and magnesium don't suffer nearly as much thermally-related
shape changes as plastic, older lenses and new high-end principally
metal lenses do not have the problem.

Sigma's biggest problem is their lying about the crappy technology used
in their overpriced, mediocre equipment.

Sigma does produce a few very good lenses.

In particular the FF 180mm f/3.5 (1:1) macro gives stellar results while
also providing good standoff distance (doesn't frighten the subject or
obstruct as much light as 100 or 50mm macros).

They've introduced an f/2.8 version recently. I don't know how well it
performs - but I'd bet it's every bit as good as the f/3.5.


--
"Civilization is the limitless multiplication of unnecessary necessities."
-Samuel Clemens.

Sigma highlights another problem with plastics, thermal change
 

In article , Alan Browne
wrote:

Sigma's biggest problem is their lying about the crappy technology used
in their overpriced, mediocre equipment.

Sigma does produce a few very good lenses.

if you luck out and get a good one, yes, but unfortunately, their
quality control is all over the map and it might take several copies to
do that.

In particular the FF 180mm f/3.5 (1:1) macro gives stellar results while
also providing good standoff distance (doesn't frighten the subject or
obstruct as much light as 100 or 50mm macros).

the tamron 180mm is a far more reliable choice than the sigma 180,
following in the footsteps of the tamron 90mm, which is one of the best
macro lenses made.

Sigma highlights another problem with plastics, thermal change
 

On 2012-06-17 14:55 , nospam wrote:
In article , Alan Browne
wrote:

Sigma's biggest problem is their lying about the crappy technology used
in their overpriced, mediocre equipment.

Sigma does produce a few very good lenses.

if you luck out and get a good one, yes, but unfortunately, their
quality control is all over the map and it might take several copies to
do that.

In particular the FF 180mm f/3.5 (1:1) macro gives stellar results while
also providing good standoff distance (doesn't frighten the subject or
obstruct as much light as 100 or 50mm macros).

the tamron 180mm is a far more reliable choice than the sigma 180,
following in the footsteps of the tamron 90mm, which is one of the best
macro lenses made.

Since I have DIRECT knowledge of the Sigma in question I know there are
no doubts as to its quality - build and esp. in light of the images it
produces. A friend (who photographs more than most people) has had the
"film era" f/3.5 version for over 10 years and continues to put it to
great use. I'll take his experience and photos over net lore.

--
"Civilization is the limitless multiplication of unnecessary necessities."
-Samuel Clemens.

Sigma highlights another problem with plastics, thermal change
 

Alan Browne wrote:
On 2012-06-17 14:55 , nospam wrote:
In article , Alan Browne


Sigma does produce a few very good lenses.

if you luck out and get a good one, yes, but unfortunately, their
quality control is all over the map and it might take several copies to
do that.

In particular the FF 180mm f/3.5 (1:1) macro gives stellar results while

the tamron 180mm is a far more reliable choice than the sigma 180,

Since I have DIRECT knowledge of the Sigma in question I know there are
no doubts as to its quality - build and esp. in light of the images it
produces. A friend (who photographs more than most people) has had the
"film era" f/3.5 version for over 10 years and continues to put it to
great use. I'll take his experience and photos over net lore.

Doesn't say much about problems with QC. You two 'lucked out'
and got a good copy. Noone says Sigma cannot build good lenses
--- only that they don't do that consistently enough for comfort.

-Wolfgang

Sigma highlights another problem with plastics, thermal change
 

On Wed, 20 Jun 2012 11:27:56 +0200, Wolfgang Weisselberg
wrote:
: Alan Browne wrote:
: On 2012-06-17 14:55 , nospam wrote:
: In article , Alan Browne
:
:
: Sigma does produce a few very good lenses.
:
: if you luck out and get a good one, yes, but unfortunately, their
: quality control is all over the map and it might take several copies to
: do that.
:
: In particular the FF 180mm f/3.5 (1:1) macro gives stellar results while
:
: the tamron 180mm is a far more reliable choice than the sigma 180,
:
: Since I have DIRECT knowledge of the Sigma in question I know there are
: no doubts as to its quality - build and esp. in light of the images it
: produces. A friend (who photographs more than most people) has had the
: "film era" f/3.5 version for over 10 years and continues to put it to
: great use. I'll take his experience and photos over net lore.
:
: Doesn't say much about problems with QC. You two 'lucked out'
: and got a good copy. Noone says Sigma cannot build good lenses
: --- only that they don't do that consistently enough for comfort.

How many Sigma lenses have you ever owned, Wolfgang? How good were they?

Bob

Sigma highlights another problem with plastics, thermal change
 

Robert Coe wrote:
On Wed, 20 Jun 2012 11:27:56 +0200, Wolfgang Weisselberg

: Doesn't say much about problems with QC. You two 'lucked out'
: and got a good copy. Noone says Sigma cannot build good lenses
: --- only that they don't do that consistently enough for comfort.

How many Sigma lenses have you ever owned, Wolfgang? How good were they?

I shall refer you to lensrentals.com, who have owned *many* dozen.

Another 1 or 3 or 10 lenses from me doesn't make a difference
to statistics. Just as one lottery winner doesn't mean every
ticket wins the main price.

-Wolfgang

Sigma highlights another problem with plastics, thermal change
 

On Sun, 24 Jun 2012 02:37:11 +0200, Wolfgang Weisselberg
wrote:
: Robert Coe wrote:
: On Wed, 20 Jun 2012 11:27:56 +0200, Wolfgang Weisselberg
:
: : Doesn't say much about problems with QC. You two 'lucked out'
: : and got a good copy. Noone says Sigma cannot build good lenses
: : --- only that they don't do that consistently enough for comfort.
:
: How many Sigma lenses have you ever owned, Wolfgang? How good
: were they?
:
: I shall refer you to lensrentals.com, who have owned *many* dozen.
:
: Another 1 or 3 or 10 lenses from me doesn't make a difference
: to statistics. Just as one lottery winner doesn't mean every
: ticket wins the main price.

In other words, none. I thought as much.

Since I suppose you'll ask, or assume, my wife and I own four of them. Are
they the best lenses we own? No. But all have been a very good value for the
money.

Bob

Sigma highlights another problem with plastics, thermal change
 

Robert Coe wrote:
On Sun, 24 Jun 2012 02:37:11 +0200, Wolfgang Weisselberg
: Robert Coe wrote:
: On Wed, 20 Jun 2012 11:27:56 +0200, Wolfgang Weisselberg

: : Doesn't say much about problems with QC. You two 'lucked out'
: : and got a good copy. Noone says Sigma cannot build good lenses
: : --- only that they don't do that consistently enough for comfort.

: How many Sigma lenses have you ever owned, Wolfgang? How good
: were they?

: I shall refer you to lensrentals.com, who have owned *many* dozen.

: Another 1 or 3 or 10 lenses from me doesn't make a difference
: to statistics. Just as one lottery winner doesn't mean every
: ticket wins the main price.

In other words, none. I thought as much.

Looks like you try to invent facts.


Since I suppose you'll ask, or assume, my wife and I own four of them. Are
they the best lenses we own? No. But all have been a very good value for the
money.

Ok. You own *F*O*U*R* Sigma lenses. Probably bought over
several years. How many percent of Sigma's lenses are they?

Consider: their annual turnover is 36 billion yen (that's roughly
450 million USD).

See the point why 4 so-so-but-real-cheap lenses just don't say much?
We get many more 1 million EUR lottery winners per year ...
from a single lottery.

-Wolfgang

Sigma highlights another problem with plastics, thermal change
 

In article , Robert Coe
wrote:

: : Doesn't say much about problems with QC. You two 'lucked out'
: : and got a good copy. Noone says Sigma cannot build good lenses
: : --- only that they don't do that consistently enough for comfort.
:
: How many Sigma lenses have you ever owned, Wolfgang? How good
: were they?
:
: I shall refer you to lensrentals.com, who have owned *many* dozen.
:
: Another 1 or 3 or 10 lenses from me doesn't make a difference
: to statistics. Just as one lottery winner doesn't mean every
: ticket wins the main price.

In other words, none. I thought as much.

Since I suppose you'll ask, or assume, my wife and I own four of them. Are
they the best lenses we own? No. But all have been a very good value for the
money.

four lenses is nothing.

lensrentals has *hundreds* of sigma lenses. dozens *each* of nearly
every model sigma lens made.

well they used to, until they found out that sigma lenses had horrific
failure rates, as high as 90% (really). many of them failed out of the
box, before they were even rented to anyone. worse, sigma gave the a
runaround to get them fixed, blaming lensrentals for breaking them.
there was a lengthy blog on their website about it.

now they only carry sigma lenses if there's no alternative from another
manufacturer.