Hello, Wondering if this Sigma consistently focuses accurately. The Digital Picture says, "I have thrown out as many as 70% or more images from a single shoot of over 100 non-action, wide aperture shots because they were very OOF (Out of Focus)... It is possible that another copy of this lens would focus more consistently, but my guess (helped by feedback from others) is that my lens is representative of this model. http://www.the-digital-picture.com/Reviews/Sigma-50mm-f-1.4-EX-DG-HSM-Lens-Review.aspx But, DP Preview says, "Focus accuracy was generally impressive, although with a certain tendency towards slight front-focus at close distances and F1.4, especially with low-contrast subjects. The lens also shows some evidence of a slight focus shift to the rear on stopping down, which meant our sample focused correctly when set to F2." http://www.dpreview.com/lensreviews/sigma_50_1p4_c16/ So, is the problem generally inconsistent autofocus, or just a "slight" front-focus at f/1.4? If it does just front-focus slightly at f/1.4, how much is this? (I would want to use f/1.4, but generally no closer than 6 feet away on a crop sensor camera). Thanks.