Wow! 4 focus points! Thats precision for ya.
But its like saying "yea, we know we have crap qc control, u dont like it, buy the usb dock and use that, thats the best we want to do, now piss off"
Still my question is why all the adjustments are necessary?
why not better tuning at the plant? I dont accept human error, money it Costs for the qc. Thats unacceptable. People are accepting what mfr give ani think its wrong. Prices go higher and produxts are crappier qc. I dont care to hear their excuses of bad qc. There is reason for it.
Actually, that's not the case at all. Every zoom is going to vary along its length to some extent, even if it's -2 here and +2 there. That's a 5 point range, which when taken across the length of a zoom isn't too bad at all and may hardly be noticeable. But some folks, and pros in particular, will notice it. By brother walks around with Canon gear worth in the high five-figures, and he is as anal as they get with focus tuning. Canon allows two adjustment points on zooms
(are you listening Nikon?!) and he still complains about some zooms being off in spots, so it's not a QC issue. He picked up a new Sigma 120-300mm "Sports" lens and raved about the precision which with he could get it tuned to his 5D. However, it seems there's a thing in the focus routines on the 1D's that made this lens go from +17 at 200mm to -16 at 300mm, and the range in between was crap for focus tuning. A full blog on his experience with the lens, Canon and Sigma customer service can be read
here, but suffice it to say that after trips to the Sigma shop in NY, exchanges with their engineers and receiving a custom tuned replacement direct from Sigma they were never able to overcome the issue, which is buried in the firmware of the Canon 1D's (something confirmed by his Canon rep). The lens has zero issues with any other body, and as much as he loves it he no longer owns the lens since it won't work with his work camera.
The truth is, there are subtle intricacies with different pieces of equipment that make focus tuning necessary in order to achieve perfect focus, and it's not just to overcome poor quality control. So you can bitch and call it a cop out, but there are people out there who require a level of precision that Sigma is stepping up to provide for their customers. Because it's not on the cheap consumer gear that they're offering this level of tuning on, it's on their high end Art and Sports series lenses - like those that some people whine about costing $1300 out of the box. You can't have it both ways, dude. But I get it, you have this thing against Sigma.
