Sigma 1.4x Teleconverter review: Sigma’s budget-friendly lens extender offers hefty savings at the expense of image quality


posted Wednesday, September 18, 2013 at 3:26 PM EST


We just posted our review of the Sigma 1.4X EX DG APO teleconverter which we received alongside the company's new 120-300mm ƒ/2.8 DG OS HSM "S" telephoto zoom lens. Like Canon's Extender EF 1.4X III and Nikon's 1.4X AF-S TC-14E II, the Sigma model also provides a 1.4x increase in focal length for your telephoto lenses, at the expense of one stop of light. For example, with the Sigma 1.4x, your 200mm ƒ/2.8 lens is transformed into a 280mm ƒ/4 lens.

The big reason that shooters might choose the Sigma version of the 1.4x extender is price. At around $225, the Sigma 1.4X EX DG APO costs about half that of competing models from the Canon and Nikon. However, as the old adage says "you get what you pay for," and it unfortunately appears to have followed suit with this Sigma teleconverter. 

Right off the bat, we noticed some extreme optical problems with the first test copy of the Sigma 1.4X EG DG APO. We quickly requested a second copy, and then a third. All three versions, paired with the Sigma 120-300mm lens, showed significant softness on the right side of the images when using a full-frame camera. We knew the problem wasn't with the 120-300mm, as we had recently tested it and found it to be a top performer optically.

We were finally able to get a fourth copy of this teleconverter (with a much different serial number than the other three) to really -- once and for all -- find out if you could get a good version of this teleconverter. So, was this copy indeed a good copy or another dud? Head on over to to check out the full Sigma 1.4X teleconverter review to see how it held up to our standard battery of tests!