I went out to look for a copy of the new Sigma 50 Art lens for my Canon camera. Tried two copies at different stores in Sydney and both didn't focus correctly. I checked the samples when I got home and found that it was front focusing. At f/1.4 the aperture is so narrow that it would be difficult to focus as it is. Next time I should try testing them at f/2 to f/5.6. The price is a little steep at the moment anyway so I'm in no hurry to try another copy. I want a 50mm lens but it doesn't have to be the Sigma 50mm Art.
These are not scientific tests. They're simply quick snaps on my Canon 6D in store with the Sigma 50mm Art at f/1.4. Only tweaked the exposure in post before resizing for upload. Click on an image to enlarge.
The nose and face of the sales guy is sharp, but only one side of his face due to the narrow depth of field. But that wasn't where my autofocus points were. It was the center dot pointed at his forehead!
The image below was completely out of focus!
Shot another customer's back. I aimed at the back of his head and the area where the AF point was targeting was blurry. The space where his jacket/back was sharp. That's frustrating!
Conclusion: I may have to go to a store and ask them to use a focusing chart to do some proper tests. I do frequently use a focus-recompose method with my photography. The conditions in the shop were not exactly ideal but then again, shooting in the shop was a real world scenario, where you do not getting optimal conditions to get perfect images. Both copies of the Sigma 50 Art lens fell below my expectations today. I might try again another time, and when stock levels aren't so low anymore.
I bumped into Isaac Leung / Pireze at Georges Camera Store in the city. He picked up an Elinchrom Rotalux Deep Octa 100cm modifier and diffuser set for his work. He intends to adapt it to speedlites. Isaac was one of my main inspirations in getting into strobist work, so it was an interesting conversation and unexpected catch-up.
I'm also considering another studio flash head (up to 400ws), a boom arm, and a choice between the 70cm Deep Octa or the 55cm beauty dish with grid. These considerations are clashing with my desire to purchase a Sigma 50 Art immediately. I think the strobist equipment would get me further with my photography than the Sigma optics. The strobist gear should do a lot more because it adds a new dimension to my current clam-shell 2-light setup. I want to use 3 or 4 lights to get the full studio look going.