Sigma "DC" 18mm F3.5 - 200mm 6.3 on my Pentax *ist D

Archived from groups: rec.photo.digital.slr-systems (More info?)

Perhaps more of a technical question but here it goes.
Bought a new lens (see subject line) made specifically for my type of DSLR.
I love the range because I'm going on a trip and the wide range will
minimize the swapping of lens and I can use a smaller camera bag. I've been
told that the trade off is that my other lenses (Pentax SMC 18-35, 28-80,
300) will result in sharper more colourful results than the wide range. Is
this true?

So far I've been happy with the new lens but I haven't really had a chance
to use it under all conditions.
Any input appreciated.

Archived from groups: rec.photo.digital.slr-systems (More info?)

> If you were unsure about the lens, why did you buy it?

Gee, that's helpful advice

Toa

Archived from groups: rec.photo.digital.slr-systems (More info?)

I own this lens.
This is not the world's greatest lens but is actually a very good performer
for what it is and far superior to the horrible 28-200/300 genre for 35mm
cameras, probably because the lens only has to cover the size of the smaller
dSLR sensor.
I bought the Sigma for travel after trying and returning 3 new Nikon
55-200mm lenses.
To be charitable, the Nikon 55-200 is an utter piece of garbage that cannot
focus and has terrible optical and mechanical problems completely washed
over in the review in PopPhoto (in 30 years of reading that magazine I have
never seen a review of a piece of equipment that was such an absurdity). In
over 30 years of using Nikons, obviously I like Nikon, I have never seen
anything made by Nikon for SLRs that was of such poor quality as this new
55-200mm lens.
No one should buy that lens, but they will. It is no bargain at a retail
price of $280.
The Sigma totally outperforms the Nikon in the 55-200 range. It is sharp,
contrasty, has low flare and low distortion. The Sigma can actually find
focus rapidly while the 55-200 hunts and pecks due to imprecision with its
autofocus mechanism and what must be execrable flare and low contrast such
that the camera autofocus sensor cannot find adequate maximum contrast.
Look at a point source of light with your favorite lens, the Sigma 18-200
and the Nikon 55-200. The issues become obvious.
The Sigma has slight vignetting at lowest focal length shooting wide open
that disappears within about two f stops.
At the widest angle/lowest focal length distortion may be visible, depending
on subject matter. It disappears by dialing in a setting of 2-4 in the new
Photoshop CS2 lens/distortion filter! The Nikon kit lens that comes with the
D70 is a bit better at the lowest focal length because of less distortion.
Put it this way: I just got back from a three week trip in Asia with the
Sigma 18-200 on a D70 (raw only). I have no complaints about the lens, which
for me is very unusual. I can't blame the lens for my aesthetic shortcomings
.. . .

Archived from groups: rec.photo.digital.slr-systems (More info?)

Paul Mitchum wrote:
> Gaderian <nospam@anisp.com> wrote:
>
>> Perhaps more of a technical question but here it goes.
>> Bought a new lens (see subject line) made specifically for my type of
>> DSLR. I love the range because I'm going on a trip and the wide
>> range will minimize the swapping of lens and I can use a smaller
>> camera bag. I've been told that the trade off is that my other
>> lenses (Pentax SMC 18-35, 28-80, 300) will result in sharper more
>> colourful results than the wide range. Is this true?
>>
>> So far I've been happy with the new lens but I haven't really had a
>> chance to use it under all conditions.
>> Any input appreciated.
>
> If you were unsure about the lens, why did you buy it?

Who says I was unsure? You just made an assumption.
This question is a result of a person who prompted me to ask this question
"after" I bought the lens.
Too bad you are incapable of articulating the original post and contributing
to this news group.

Archived from groups: rec.photo.digital.slr-systems (More info?)

birdman wrote:
> I own this lens.
<snip>

Excelent input! Thanks!

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Gaderian" <nospam@anisp.com> writes:

> Perhaps more of a technical question but here it goes.
> Bought a new lens (see subject line) made specifically for my type of DSLR.
> I love the range because I'm going on a trip and the wide range will
> minimize the swapping of lens and I can use a smaller camera bag. I've been
> told that the trade off is that my other lenses (Pentax SMC 18-35, 28-80,
> 300) will result in sharper more colourful results than the wide range. Is
> this true?

Generally speaking, yes. It's harder to design, build, and assemble a
very wide-range zoom lens than a fixed-focal-length or smaller zoom
range lens. A wide-range, cheap lens is always slow (small maximum
aperture), and generally somewhat soft at one end or the other
compared to the best lenses of the focal length.

On the other hand, often the difference isn't big enough to show to
most people in a 4x6 print.

> So far I've been happy with the new lens but I haven't really had a chance
> to use it under all conditions.

Checking it out in your own uses and comparing it to your other lenses
is the best way to reach your conclusion. If you do that, your
conclusion will be right for you, regardless of what the rest of us
think.
--
David Dyer-Bennet, <mailtod-b@dd-b.net>, <http://www.dd-b.net/dd-b/>
RKBA: <http://noguns-nomoney.com/> <http://www.dd-b.net/carry/>
Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <http://dragaera.info/> Much of which is still down

Archived from groups: rec.photo.digital.slr-systems (More info?)

usenet@mile23.c0m (Paul Mitchum) wrote:
>Gaderian <nospam@anisp.com> wrote:
>> Paul Mitchum wrote:
>> > Gaderian <nospam@anisp.com> wrote:
>> >
>> >> Perhaps more of a technical question but here it goes.
>> >> Bought a new lens (see subject line) made specifically for my type of
>> >> DSLR. I love the range because I'm going on a trip and the wide
>> >> range will minimize the swapping of lens and I can use a smaller
>> >> camera bag. I've been told that the trade off is that my other
>> >> lenses (Pentax SMC 18-35, 28-80, 300) will result in sharper more
>> >> colourful results than the wide range. Is this true?
>> >>
>> >> So far I've been happy with the new lens but I haven't really had a
>> >> chance to use it under all conditions.
>> >> Any input appreciated.
....
>If you've been happy with the lens, what's the problem? If you have the
>other lenses, you can compare. Reading a newsgroup won't give you a
>basis for comparison; if you've got all four lenses, figure out some
>shooting tests and shoot. Figure out if there are any down sides to the
>superzoom. If there are, figure out if they're worth it to only carry
>one lens.

While all of that is true, it simply misses the point. Yes he
has the lenses, and can make the comparisons, but it still is
nice to compare notes with others and learn from their
experience. That is particularly true when it is possible that
others may have a much wider range of experience and/or talent.

Regardless of that, it is an interesting topic and one of
significance right now because there are new wide range zoom
lenses on the market. I would be very interested in hearing
about comparisons for 28-300mm zoom lenses. I just purchased a
used Nikon D1 with a 80-200mm f2.8 Nikon AF and a 20mm f2.8
fixed lens. I need both a "normal" lens and a longer lens too;
hence I've just started looking at these 28-300mm f3.5/6.3 zoom
lenses and obviously would greatly benefit from other's
experiences *before* making any decisions on what to purchase.

It appears, at initial first blush, as if one of the 28-300mm
f/3.5 zoom lenses (Tameron seems good, as does Sigma) would be
ideal. The new versions are relatively smaller and lighter than
the older versions. The Sigma lens costs a little more, but not
much. The Sigma lens has slightly greater maximum magnification
(1:3.8 vs 1:2.9) and weighs slightly less (.84lb vs .93lb).
They both use the same filter sizes, have the same f-stop range,
and minimum focus distance.

Given that these lenses are intended for 35mm they should
provide excellent sharpness on a digital camera with a smaller
"film size"??? And packing a one pound lens around should be
far more convenient that packing 2 or 3 lenses (particularly when
one is a large 80-200mm zoom, even if it is a superb lens).

So, the question is... how do these lenses stack up against
each other, and against the definitely higher quality Nikon
lenses?

--
FloydL. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com