Some samples from the Sigma 18-50mm f/2.8 EX DC lens [Archive]

View Full Version : Some samples from the Sigma 18-50mm f/2.8 EX DC lens

slejhamer

20th of February 2005 (Sun), 13:19

Not a thorough review, just a few snaps in the park, some 100% crops and my comments:

CLICK HERE (http://www.pbase.com/m_schlesinger/sigma_18_50_lens)

(Hopefully pbase is working... :rolleyes: )

Sisko

20th of February 2005 (Sun), 14:45

Those look good.

This would be an excellent replacement for the kit lens, similar focal length range but a faster lens.

I would like a Canon 17-40L, but it is dearer than the Sigma and slower at only f4.

Thanks for posting.

Bob_A

20th of February 2005 (Sun), 21:49

The Canon EF-S 18-55 is reviewed at Photozone as one of the worst lenses available. Photozone lists the Sigma as "average" ... which is a much, much higher rating than the Canon (which is rated "very poor"). The Canon 17-40L is a slower lens, but has optics that the Sigma can't match.

For lenses I've used the Photozone reviews have been spot on ...

Bob

mdude85

20th of February 2005 (Sun), 22:07

Well, you did stop this lens down quite a bit (f/16!). Any lens is going to be sharp at that aperture. How about posting some shots at f2.8?

ron chappel

21st of February 2005 (Mon), 04:49

yeah f2.8 will be the decider.

Olegis

21st of February 2005 (Mon), 05:20

There ARE picture and crop at f/2.8 : here (http://www.pbase.com/m_schlesinger/image/39971631) and here (http://www.pbase.com/m_schlesinger/image/39971630). This lens sure looks quite impressive !

slejhamer

21st of February 2005 (Mon), 06:15

How about posting some shots at f2.8?
yeah f2.8 will be the decider.

Er, uhm, did you not notice the comparison of the butterfly garden ornament at f/2.8 and f/4? With 100% crops? :confused:

There ARE picture and crop at f/2.8.

Bless you! :D

Photozone lists the Sigma as "average" ...

Where do you see that? I see "good" to "very good" performance ratings for this lens for everything except wide open at the wide end, which they rate "poor." (I disagree with that one. ;) )

The Canon 17-40L is a slower lens, but has optics that the Sigma can't match.

My observations about the 17-40 are based on the one that I had, and it may have been a bad copy as I've noted in another thread. But the Canon was not only slower, it also had terrible AF in low light. Also, it was not any sharper at f/4 than the Sigma is at f/2.8.

The Sigma is more prone to flare if the sun is in the frame. There is some barrel distortion at the wide end. The Canon was better in both areas. Also the Sigma shows some very minor purple fringing around specular highlights, which the Canon did not.

So in some ways the Canon has better optics, and it other ways it doesn't.

I'll take focus accuracy over minor barrel distortion ... :)

This lens sure looks quite impressive !

Indeed! If one is willing to accept the inherent limitation of a "digital" lens, it's well worth a try.

YMMV,

mdude85

21st of February 2005 (Mon), 10:54

Let's see THIS one at f2.8.

http://www.pbase.com/m_schlesinger/image/39971620

DocFrankenstein

21st of February 2005 (Mon), 14:38

You're a brave man to get and test this thing.

kudos

ron chappel

21st of February 2005 (Mon), 19:31

mdude85

24th of February 2005 (Thu), 23:56

Oops,yeah...late night post is my excuse:o ,sorry

Ahh ,now i see.
Yeah-it's pretty crappy at f2.8. f4 sharpens up an amazing amount though!!:eek:

It would be ineteresting to find the exact point where it improves (like f3.2 or whatever) and stay above that fstop most times
Thanks for the demo slejhamer!

Excuse me for my ignorance but why would someone spend the extra money to get a fast lens only to stay a half stop above the max? The goal is that you'll find a lens that is sharp wide open.

DocFrankenstein

25th of February 2005 (Fri), 00:05

Excuse me for my ignorance but why would someone spend the extra money to get a fast lens only to stay a half stop above the max? The goal is that you'll find a lens that is sharp wide open.
My 18-55 is softer than that "wide open" at 5.6

Sharpness is relative. Sometimes, having a faster lens would give you low enough shutter speed to avoid blur. Had u been using a sharp slow lens, it'd be blurred...

And IMO that lens is enough to print nice 8*12

michael.luczkow

25th of February 2005 (Fri), 03:27

doc i like your signature.

slejhamer

25th of February 2005 (Fri), 04:28

Excuse me for my ignorance but why would someone spend the extra money to get a fast lens only to stay a half stop above the max? The goal is that you'll find a lens that is sharp wide open.

Please point out the wide-angle zoom lens that is as sharp at f/2.8 as it is stopped down. Not even the Canon 16-35 f/2.8L meets this criteria.