Comment on Sigma service

ScooterMaxi Jim · 09-04-2015, 02:03 PM - **1 Like**

We've been posting here quite a bit about service quality and times. In a thread not long ago, I mentioned an issue with a discontinued lens sold new with refurbished warranty card (90 days) that was heading for service. It is the Sigma 12-24 EX f/4.5-5.6 (version one that ended production in 2011; replacement is not produced in Pentax mount); purchased at a low price for mercenary reasons, knowing that the full frame camera will put the lens in pretty strong demand soon enough.

The tent sale unit was obviously new stock, but testing quickly identified that there was significant decentering causing blurring and CA on the left side. Response from Sigma by posting repair notice and image showing decentering came in under 3 hours confirming my diagnosis. Sent in the lens using slowest mail possible, and received a new lens (with similar refurbished warranty card) in 8 days; apparently Sigma's very good customer service infected the USPS, as well! Every aspect of the experience was top-notch, and the new lens seems to be fine in all respects.

Regarding the few reviews you see out there regarding the 12-24 EX, it seems that there is wide disagreement about the extent of CA. Possibly the reviews indicating high CA were lenses with some decentering or other alignment issue. The difference in CA between the returned lens and the new one is very considerable. For a UWA zoom, the relative lack of CA is very impressive - only slightly behind what a very good 14mm prime can achieve, and way ahead of the original Tokina 12-24 (similar to the Pentax in design). This is especially impressive because the lens is very close to true rectilinear.

Here's a pretty thorough workout review of the lens that includes crop digital and FF on film. It seems a fair assessment based on a good copy of the lens:

Practically A Prime: The Sigma EX 12-24/4.5-5.6

condor27596 · 09-04-2015, 02:31 PM

Thanks for such a detailed review.

btnapa · 09-04-2015, 04:55 PM

Originally posted by ScooterMaxi Jim

We've been posting here quite a bit about service quality and times. In a thread not long ago, I mentioned an issue with a discontinued lens sold new with refurbished warranty card (90 days) that was heading for service. It is the Sigma 12-24 EX f/4.5-5.6 (version one that ended production in 2011; replacement is not produced in Pentax mount); purchased at a low price for mercenary reasons, knowing that the full frame camera will put the lens in pretty strong demand soon enough.

The tent sale unit was obviously new stock, but testing quickly identified that there was significant decentering causing blurring and CA on the left side. Response from Sigma by posting repair notice and image showing decentering came in under 3 hours confirming my diagnosis. Sent in the lens using slowest mail possible, and received a new lens (with similar refurbished warranty card) in 8 days; apparently Sigma's very good customer service infected the USPS, as well! Every aspect of the experience was top-notch, and the new lens seems to be fine in all respects.

Regarding the few reviews you see out there regarding the 12-24 EX, it seems that there is wide disagreement about the extent of CA. Possibly the reviews indicating high CA were lenses with some decentering or other alignment issue. The difference in CA between the returned lens and the new one is very considerable. For a UWA zoom, the relative lack of CA is very impressive - only slightly behind what a very good 14mm prime can achieve, and way ahead of the original Tokina 12-24 (similar to the Pentax in design). This is especially impressive because the lens is very close to true rectilinear.

Here's a pretty thorough workout review of the lens that includes crop digital and FF on film. It seems a fair assessment based on a good copy of the lens:

Practically A Prime: The Sigma EX 12-24/4.5-5.6

I have had a few occasions that I had to use Sigma warranty and they delivered with flying colors. I had the Sigma 12-24 for my Canon and it overlapped a Sigma 15-30. The qualities were close enough in the copies I had. I contemplated the 12-24 for my Pentax system but bought the 10-20 f3.5-4.5 instead of a wider view. The 10-20 is not in the sam class as the 12-24. Stopped down the 10-20 is very good and wide open it is decent.

Thanks for the post it was very informative.

09-04-2015, 02:03 PM - 1 Like	#1
ScooterMaxi Jim Veteran Member Join Date: Jul 2009 Location: Minnesota Posts: 1,520	Comment on Sigma service We've been posting here quite a bit about service quality and times. In a thread not long ago, I mentioned an issue with a discontinued lens sold new with refurbished warranty card (90 days) that was heading for service. It is the Sigma 12-24 EX f/4.5-5.6 (version one that ended production in 2011; replacement is not produced in Pentax mount); purchased at a low price for mercenary reasons, knowing that the full frame camera will put the lens in pretty strong demand soon enough. The tent sale unit was obviously new stock, but testing quickly identified that there was significant decentering causing blurring and CA on the left side. Response from Sigma by posting repair notice and image showing decentering came in under 3 hours confirming my diagnosis. Sent in the lens using slowest mail possible, and received a new lens (with similar refurbished warranty card) in 8 days; apparently Sigma's very good customer service infected the USPS, as well! Every aspect of the experience was top-notch, and the new lens seems to be fine in all respects. Regarding the few reviews you see out there regarding the 12-24 EX, it seems that there is wide disagreement about the extent of CA. Possibly the reviews indicating high CA were lenses with some decentering or other alignment issue. The difference in CA between the returned lens and the new one is very considerable. For a UWA zoom, the relative lack of CA is very impressive - only slightly behind what a very good 14mm prime can achieve, and way ahead of the original Tokina 12-24 (similar to the Pentax in design). This is especially impressive because the lens is very close to true rectilinear. Here's a pretty thorough workout review of the lens that includes crop digital and FF on film. It seems a fair assessment based on a good copy of the lens: Practically A Prime: The Sigma EX 12-24/4.5-5.6

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09-04-2015, 02:31 PM	#2
condor27596 Veteran Member Join Date: Sep 2012 Location: Raleigh, NC, USA Posts: 870	Thanks for such a detailed review.

09-04-2015, 04:55 PM	#3
btnapa Pentaxian Join Date: Oct 2013 Posts: 1,616	Originally posted by ScooterMaxi Jim We've been posting here quite a bit about service quality and times. In a thread not long ago, I mentioned an issue with a discontinued lens sold new with refurbished warranty card (90 days) that was heading for service. It is the Sigma 12-24 EX f/4.5-5.6 (version one that ended production in 2011; replacement is not produced in Pentax mount); purchased at a low price for mercenary reasons, knowing that the full frame camera will put the lens in pretty strong demand soon enough. The tent sale unit was obviously new stock, but testing quickly identified that there was significant decentering causing blurring and CA on the left side. Response from Sigma by posting repair notice and image showing decentering came in under 3 hours confirming my diagnosis. Sent in the lens using slowest mail possible, and received a new lens (with similar refurbished warranty card) in 8 days; apparently Sigma's very good customer service infected the USPS, as well! Every aspect of the experience was top-notch, and the new lens seems to be fine in all respects. Regarding the few reviews you see out there regarding the 12-24 EX, it seems that there is wide disagreement about the extent of CA. Possibly the reviews indicating high CA were lenses with some decentering or other alignment issue. The difference in CA between the returned lens and the new one is very considerable. For a UWA zoom, the relative lack of CA is very impressive - only slightly behind what a very good 14mm prime can achieve, and way ahead of the original Tokina 12-24 (similar to the Pentax in design). This is especially impressive because the lens is very close to true rectilinear. Here's a pretty thorough workout review of the lens that includes crop digital and FF on film. It seems a fair assessment based on a good copy of the lens: Practically A Prime: The Sigma EX 12-24/4.5-5.6 I have had a few occasions that I had to use Sigma warranty and they delivered with flying colors. I had the Sigma 12-24 for my Canon and it overlapped a Sigma 15-30. The qualities were close enough in the copies I had. I contemplated the 12-24 for my Pentax system but bought the 10-20 f3.5-4.5 instead of a wider view. The 10-20 is not in the sam class as the 12-24. Stopped down the 10-20 is very good and wide open it is decent. Thanks for the post it was very informative.