James recently asked the following question:
I'm going into real estate photography I have a Canon 1200D. I'm just wondering if there is a difference between the Canon 10-18 lens and the Sigma 10-20. I see the Canon lens is slightly cheaper will I be OK with the Canon lens?
For years, Sigma 10-20mm f/4-5.6 lens has been one of the go-to lenses for real estate photography but in the summer of 2014, Canon introduced the Canon 10-18mm f/4-5.6 wide-angle lens for $299. At first, it wasn't clear how the Canon 10-18mm stacked up against the Sigma.
Now, it's pretty clear that the Canon 10-18 f/4-5.6 and Sigma 10-20 f/4-5.6 are very close in quality. Check the DxOmark comparison here. The Sigma tests slightly better than the Canon. For a long time, Sigma kept all versions of the 10-20mm f/4-5.6 priced around $429 as it had been for years but now the Sigma has dropped their price to $340 for only the Canon mount lens but left the Nikon, Sony, Pentax versions (same lens with different mounts) of the lens at $479. This clearly indicates the competition Sigma feels from the Canon 10-18mm.
The Canon 10-18 has some other distinct advantages:
For Nikon, Sony and Pentax cropped sensor bodies the Sigma 10-20mm is still probably one of the best choices of a wide-angle lens for real estate shooting.