Canon 17-55mm or sigma 18-35mm ?

Your analysis Ignores one key dimension: Image Quality

I've tried to classify by specifications, eg Benz E Class vs BMW 5 Series vs Audi A6 vs Lexus GS.
The image quality is best represented by 4-way comparison tests like these: http://youtu.be/T3UfbsdfUu8
Great video - the 18-35 does come out best on image quality...

Your analysis Ignores one key dimension: Image Quality

I've tried to classify by specifications, eg Benz E Class vs BMW 5 Series vs Audi A6 vs Lexus GS.
The image quality is best represented by 4-way comparison tests like these: http://youtu.be/T3UfbsdfUu8
Great video - the 18-35 does come out best on image quality...

Of course. If image quality (and build quality and speed) is your top concern, the choice is starkly clear, the Sigma 18-35.

No issues or worries on mine. The HSM is as quick and silent as Canon USM.

peterharvey wrote:

Your analysis Ignores one key dimension: Image Quality

I've tried to classify by specifications, eg Benz E Class vs BMW 5 Series vs Audi A6 vs Lexus GS.
The image quality is best represented by 4-way comparison tests like these: http://youtu.be/T3UfbsdfUu8
Great video - the 18-35 does come out best on image quality...

After watching that video, I was surprised at how little of a difference there was in image quality.  The Tamron was clearly the worst, but after that I didn't think the differences were very much.

Statements like "The Sigma is better at f1.8 than the Canon at 2.8" or "The Sigma resolves twice as much detail the Canon" are not supported by this video.  Maybe if he had chosen a subject with more fine detail, we'd see bigger differences.

I can see why you would discard the Tamron given this test, but why discard the Sigma?  Even in the conclusion he cannot draw a winner between the Canon and the Sigma, which is pretty much what I found as well.  The only thing I really disagree with is the build quality, I found the canon to be significantly worse feeling than the Sigma, personally.

Keith Z Leonard wrote:

I can see why you would discard the Tamron given this test, but why discard the Sigma? Even in the conclusion he cannot draw a winner between the Canon and the Sigma, which is pretty much what I found as well. The only thing I really disagree with is the build quality, I found the canon to be significantly worse feeling than the Sigma, personally.

the video said conon better than sigma in autofocus and zoom rang (not big differences )   also it has less destortion than sigma

the only thing sigma 17-50 win over canon is only the price

It is hard to tell the difference between three of the four lenses on the YouTube video, but in real life, we pixel peep, so we can easily discern the difference..

peterharvey wrote:

It is hard to tell the difference between three of the four lenses on the YouTube video, but in real life, we pixel peep, so we can easily discern the difference..

In the video he pixel peeps.  If you watched this video at full resolution, and full screen on a HD monitor, and you had a hard time telling the difference, you would also find it hard to tell the difference in real life.

I'm not saying there is not a measurable difference, I am just saying that it was surprising how minimal the difference was when pixel peeping a shot of building.

You are right - unless we pixel peep, there is very little difference between these lenses..

It's very true, if you look at the 15mp reviews on photozone you really don't see a huge difference between the canon 17-55 and sigma 17-50, most notably is the corner sharpness of the canon being significantly better at 17mm @ f2.8, other wise you generally see the Sigma is slighly sharper in the center but they are very comparable.  The same is true for just about every other aspect of the image quality tests, very comparable distortions and CA, the Sigma at 17mm is 2.9% barrel vs the 2.03% of the Canon, which is again the big win for the Canon, otherwise there isn't a significant difference.

I've printed quite a few 30x20 images from the Sigma 17-50 f2.8+7D and they are just grand.  Now that you can get this lens for under 400$ on Ebay and 570$ from Amazon it's really quite attractive, they Canon price has dropped quite a bit too though.  I think it's a tough choice between these two lenses.

The video shows a significant difference in image quality between the Sigma/Canon and the Tamron, especially in the corners.  The Sigma 18-35 is a screamer but it's a bit of an oddball in the test as it's significantly different, aperture, focal length, no IS/OS/VC.

Just for comparison:

Not quite true, the Sigma has better center sharpness and the difference in build quality to me was significant.  I used both of them for a week before making my decision.  Still, the Canon is a great lens, no question.

Canon should be ashamed of the build quality for such a pricey lens.

Keith Z Leonard wrote:

Not quite true, the Sigma has better center sharpness and the difference in build quality to me was significant. I used both of them for a week before making my decision. Still, the Canon is a great lens, no question.

thanks your posts is really helpful to me

i checked for sigma 17-50 on eBay and found smoe costs only 380$ include shipping  !

really  attractive price but i am afraid if there is difference between copies because it costs too much than amazon and us stores !

MMACory wrote:

Just for comparison:

Great sharpness

I olso like this lens but I prefer zoom lens for more use

thamer08 wrote:

Keith Z Leonard wrote:

Not quite true, the Sigma has better center sharpness and the difference in build quality to me was significant. I used both of them for a week before making my decision. Still, the Canon is a great lens, no question.

thanks your posts is really helpful to me

i checked for sigma 17-50 on eBay and found smoe costs only 380$ include shipping !

really attractive price but i am afraid if there is difference between copies because it costs too much than amazon and us stores !

Yeah, it's interesting, it's the 3rd party lens stigma all over again in that they tend not to hold their value as much, though I was able to sell mine for a quite reasonable drop from what I paid.  I think the main thing there is that I did a local sale so the guy could try the lens out and told me "this is the single best thing I've bought for my photography".  He had his rebel kit (18-55 IS) and a Sigma 30 f1.4 before buying the 17-50 f2.8 OS from me.  He also said that now he hardly uses any of his other lenses anymore, I think he was going to sell the 30mm prime.  Obviously that has to do with specific uses though.

Anyway, that's probably why the price difference, with the 6D out a lot of people seem to be making the jump to a 35mm "full frame" camera which puts a lot of these Sigmas and Canon 17-55 lenses onto the used market.  I don't think it's circumstance that both of these lenses have dropped their new prices during this time frame either.  The Sigma used to be 670$ and the Canon was around 1000$, they are both cheaper now.

Keith Z Leonard wrote:

thamer08 wrote:

Keith Z Leonard wrote:

Not quite true, the Sigma has better center sharpness and the difference in build quality to me was significant. I used both of them for a week before making my decision. Still, the Canon is a great lens, no question.

thanks your posts is really helpful to me

i checked for sigma 17-50 on eBay and found smoe costs only 380$ include shipping !

really attractive price but i am afraid if there is difference between copies because it costs too much than amazon and us stores !

Yeah, it's interesting, it's the 3rd party lens stigma all over again in that they tend not to hold their value as much, though I was able to sell mine for a quite reasonable drop from what I paid. I think the main thing there is that I did a local sale so the guy could try the lens out and told me "this is the single best thing I've bought for my photography". He had his rebel kit (18-55 IS) and a Sigma 30 f1.4 before buying the 17-50 f2.8 OS from me. He also said that now he hardly uses any of his other lenses anymore, I think he was going to sell the 30mm prime. Obviously that has to do with specific uses though.

Anyway, that's probably why the price difference, with the 6D out a lot of people seem to be making the jump to a 35mm "full frame" camera which puts a lot of these Sigmas and Canon 17-55 lenses onto the used market. I don't think it's circumstance that both of these lenses have dropped their new prices during this time frame either. The Sigma used to be 670$ and the Canon was around 1000$, they are both cheaper now.

you are right

i figured third party lenses drop down quickly compared to canon but the canon take long time to drop down and some of them go up like 70-200 series !

that also make me think to not buy sigma 18-35 at this time because it is new and may be in the next 2 years   its price go 200$ down (just expect )