[Spodeworld]

Hi,

I have the Sigma 17-70 f2.8-4.5 v1. It has a good reputation but I am thinking of upgrading to the Contemporary series. I like the prospect of improved IQ but also a silent wave motor. The new version has good reviews, but, many of them say it is weak in the corners at 17mm, to the point that it is regularly pointed out as a real fault. And, every review that pointed that out noted that it did not improve by stopping it down.

Does anyone here have enough experience to verify whether the corner weakness is really something that is strong enough to cause reconsideration of purchasing the lens. And, if you had v1 and upgraded to the Contemporary version, do you think it was a good idea.

Thanks

[JimmyDranox]

I have owned this lens, Sigma 17-70 f2.8-4.5 v1, but not the C variant. I don't know of a comparison between v1 and C, but I found another, between v2, and the C. Seems that the observation you've mentioned are right.

Sigma 17-70mm f/2.8-4 DC Macro OS Contemporary Lens Image Quality

You can change the aperture and the focal lens through the hole range. Hope that this will help you.

[Oldbayrunner]

AFAIK...most all wide angled lenses tend to be soft at the corners.. Checking photos that I have taken with both my K50 and K5 ll's with my copy 17-70mm contemporary at 17mm I don't see anything noticeably soft at the edges. Guess that's good luck for me. My copy almost lives on either one of my cameras when I am out and about and it is really quiet and quick to focus on both cameras. Others may have a different experience I can only vouch for my copy.

[stevebrot]

I have only had my Sigma 17-70/2.8-4 (C) for a little over a week, but have not done a comprehensive test. Photozone.de has tested the lens on the Nikon D7000 (16 Mpx APS-C) and his results show that while decent corner resolution wide open at 17mm that improved to f/8. I have this image posted to Flickr taken at f/5.6 and 17mm and will go upstairs and do a full resolution crop of the border and extreme corner to add a bit later.


(Taken with the K10D)

The point of focus was on the furthest right near bloom.


Here is a full resolution crop at the point of focus. I think this would qualify as "edge".



Note that PP included correction for lateral CA. Without that action the image would have been significantly softer. Even though this is a full-resolution JPEG, the conversion from RAW did cause some image degradation. A TIFF version of the same image can be downloaded from HERE.

One other caution that I might add is that since this is an internal focus lens, performance at close focus may be very different than at longer distances. The photo above was definitely close focus.


Steve

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Last edited by stevebrot; 04-27-2014 at 11:07 AM.

[SpecialK]

AFAIK...most all wide angled lenses tend to be soft at the corners..

Yep. On wide-angle lens distance to the corners is proportionately much farther than the center compared to longer lenses, so the corners will naturally be softer.

Most of my photos do not have the subject in the corner, so in practice it is a minimal consideration, which frankly, I have not noticed.

I went from v1 to C without regret.

[Spodeworld]

That's interesting stevebrot, as almost every other review I've seen says it is soft at the corners wide open, not a shock, but it never really improves significantly stopped down. If you're right, and it does substantially sharpen up in the corners stopped down I'd be more inclined to pull the trigger.

---------- Post added 04-27-14 at 12:46 PM ----------

Any thoughts on the pluses and minuses of the move from v1 to contemporary?

Thanks

Yep. On wide-angle lens distance to the corners is proportionately much farther than the center compared to longer lenses, so the corners will naturally be softer.

Most of my photos do not have the subject in the corner, so in practice it is a minimal consideration, which frankly, I have not noticed.

I went from v1 to C without regret.

---------- Post added 04-27-14 at 12:50 PM ----------

Wow, I wonder how well controlled that test is? Seems like the older version is sharper.

I have owned this lens, Sigma 17-70 f2.8-4.5 v1, but not the C variant. I don't know of a comparison between v1 and C, but I found another, between v2, and the C. Seems that the observation you've mentioned are right.

Sigma 17-70mm f/2.8-4 DC Macro OS Contemporary Lens Image Quality

You can change the aperture and the focal lens through the hole range. Hope that this will help you.

[Lititz]

FYI, PF compared the Sigma 17-70 version 1 with version 2 (also with the Pentax 17-70) here: Pentax 17-70mm Lens Comparison - Introduction - Pentax Camera Forums Of the two Sigmas, the review said "Optical performance is generally considered to be very similar between these two lenses," although later in the details the review gives a very slight edge to version 1 in optical quality. Based on that rough equality, optically, between V1 and V2, maybe you could assume that any comparison of the current C version with V2 also would apply to V1 (though note that V1 and V2 had different optical construction, albeit leading to similar results). I've only got experience with V1, and also would like to know the answer to your original question.

[stevebrot]

That's interesting stevebrot, as almost every other review I've seen says it is soft at the corners wide open, not a shock, but it never really improves significantly stopped down. If you're right, and it does substantially sharpen up in the corners stopped down I'd be more inclined to pull the trigger.

Sigma AF 17-70mm f/2.8-4 DC HSM OS | C (Nikon) - Review / Test Report - Analysis


Steve

[Oldbayrunner]

Here's a shot in raw taken with my K5 lls Acr converter No sharpen or any adjustments no crop

17mm F5.6 1/125 ISO 80

[stevebrot]

I just added a full resolution crop to my original comment above


Steve

---------- Post added 04-27-14 at 10:36 AM ----------

Wow, I wonder how well controlled that test is? Seems like the older version is sharper.

I would say the test is was not very controlled. Note the difference in magnification.


Steve

[Oldbayrunner]

Here again ACR raw No Sharpening no crop

23mm F3.5 1/320 ISO 80

[philbaum]

I wouldn't worry about it,i.e. the corners on the Sigma 17-70 C

Looking at the blur index here: Sigma Lens: Zooms - Sigma 17-70mm f/2.8-4 DC Macro OS HSM "C" (Tested) - SLRgear.com!

it looks like the 17 blur index is the worst, but the other FL and 70mm is actually quite fine. I'd much prefer a solid zoom lens at 70mm vice the 17mm end - you could always crop at the wide end :-)

Besides, the 17-70 variants are a sort of walk-around lens anyway, and you'd expect a few compromises. I have the Pentax 17-70 F4 and like it a lot. I've taken many sharp pictures of dress rehearsals for a local play company with it - many photos which have ended up in local newspapers and a local travel guide. The latest Sigma 17-70 seems to be comparable with the Pentax, but better at the long end perhaps. I think these lenses are excellent to have around. Enjoy it is my advice.

[i_trax]

I have both V1 and C , in most photos I need to remove chromatic aberration with LR, usually 5.00 is enough and I am pretty happy with both lenses.

[Spodeworld]

Nice and sharp. The 17mm is of more interest as the reviews say as you get to around 23 mm the corners improve noticeably. I am interested about the 17mm side as that will be useful for landscapes and architectural work.

I wonder if the new version focuses quicker than the screw drive variant.

Here's a shot in raw taken with my K5 lls Acr converter No sharpen or any adjustments no crop

17mm F5.6 1/125 ISO 80

[Oldbayrunner]

I know it is quicker and quieter than any of my screw drives so far.