It was too short a period of owning the Sigma 10-20mm f3.5 lens to write a review, since I returned it after only 7 days of owning it. So I decided to put it as one of my worst ever experience in using a zoom lens. I was sourcing my second Ultra Wide Angle (UWA) lens for my D7000 recently. I already owned a Tamron SP10-24mm F3.5-4.5 UWA lens and wished to get an upgrade to squeeze the maximum potential I could get out from D7000. If you still don’t aware of, I’m an advocate of UWA lens for my travel and I captured most of the Europe landmarks using UWA lens on this year and last year trips. As I’m traveling to Beijing next week, I decided to buy another UWA lens with hopes to take better images in Beijing.

So my hunt for a better quality UWA lens in the current market started last month. Don’t get me wrong. I’m still a happy owner of the Tamron lens. The only problems I encountered with Tamron 10-24 UWA is its slow focusing and serious Chromatic Aberration (CA) issues. To fulfill my ‘upgrade’ desire, my ‘going-to-be’ new UWA lens must have a faster focusing mechanism and lesser CA issues.

There are few options around in the current market. My short listed lenses available are these 2: Sigma 10-20mm f3.5 and Tokina 11-16mm f2.8. They are only RM200 (USD66) difference in price when buying new in Malaysia. While Tokina is a fraction faster (with its f2.8 pro Aperture number) and cheaper, Sigma has a wider zoom range, sexier outlook and bulkier in size (I love bulkier lens which feels more solidly built when hold in my hand ). After considering that Sigma is the latest UWA lens in the market with constant maximum Aperture (Sigma 8-16mm is the latest from 2010, but non-EX with variable Aperture No. of 4.5-5.6), albeit 200 bucks dearer, I decided and bought this Sigma home for my Nikon D7000. Below are a couple of test shots taken in the camera shop.

Above: Test shot taken with Tokina 11-16mm f2.8 UWA lens.

Below: Test shot taken with Sigma 10-20mm f3.5 UWA lens.

Photos taken with both Tokina ans Sigma are very similar in terms of sharpness, colours and distortion, except slight difference in Depth of Field was noticed, which is logic since Tokina is f2.8 while Sigma is f3.5.

I thought I was a happy man carrying this Sigma EX pro lens out to shoot some cityscape around Kuala Lumpur town. As you can see from the above photo, Sigma 10-20 f3.5 can capture really very sharp images, easily on par with, if not sharper than, the Nikkor 10-24mm f3.5-4.5 UWA. Barrel distortion and CA are more under control if compared to my Tamron.

Nightmare came after a few days. It was a nice evening just before dusk when I saw this dramatic scene of Kuala Lumpur city skyline. Then I quickly took out my camera attached with the Sigma and snapped a few shots. I left all setting to Programmed Auto Mode. Surprisingly, a simple shot like that turned out to be blur. I focused at the KLCC Twin towers again and took a few more shots to make sure ‘motion blur’ not being drawn into the picture. Then I checked on the image again, and I got a real shock. All the photos are apparently out of focus! They were actually front focused at the crane in foreground! Even I tried to focus manually, it simply couldn’t focus to infinity! What went wrong to the Sigma?

I then quickly grabbed my much cheaper Nikkor 18-105mm zoom lens and took a few shots at its widest 18mm. The result was simply awesome! There are so much different in between Nikon and Sigma! The KLCC Twin towers were back in focus! Further verifying the issue with the Focus Test Chart, it revealed that the Sigma 10-20mm f3.5 lens copy that I bought had auto focus mechanism problem! It had both occasional front and back focus and can’t focus to infinity most of the time! What’s the point of using this lens if a landscape lens can’t auto focus far objects?

I thought I just bought a lemon copy, since there are so many satisfied Sigma owners out there. So I took it back to the shop and asked for an exchange. There were only 2 units left in that shop. Unfortunately, or rather disappointingly, one of them has exactly the same problem when attached to my Nikon. What’s next? Even worse! The last Sigma 10-20mm lens available in that shop has a broken Hyper Sonic Motor (HSM), which means nothing was in focus automatically! One problematic unit out of hundreds is a lemon. 3 out of all 3 Sigma 10-20mm f3.5 lenses have problem means inferiority in Sigma’s quality standard.

I could be wrong. This could be the compatibility issue with my Nikon D7000. Other Nikon’s may not have the same issue which I didn’t know, even though I did not find any issue with my Tamron SP10-24mm when attached to D7000. So is the Tokina 11-16mm.

However, there is 1 question in my mind: How reliable is a third party lens when being attached to a Nikon camera body?

We can’t deny the superior performance of these third party lenses. Some of them can even outperform a similar ranged Nikkor lens in certain aspects and cost much cheaper than a Nikkor lens. But when come to reliability and compatibility, none of them can beat Nikkor, for Nikon camera bodies. A Sigma could take sharper images than a Nikkor, but its Auto Focus doesn’t always spot on. What’s the point if other buildings except the twin tower that you supposed to auto focus on are pin sharp? I have never experienced these kinds of issues with any my Nikkor lenses, and this is what your money paid for. At the end of the day, I returned the Sigma 10-20mm f3.5 and get a Nikkor 10-24mm f3.5-4.5 instead – Travel Feeder, your ultimate photo travel guide to Europe