another unhappy Sigma user :(

Several simplistic tests can be performed versus the battery line-up as the one depicted below i used the day i received the Sigma 50/f1.4, plus make sure you use a tripod and the delay timer which im sure you are right ?
As others have suggested post some pics with the exif intact for folks to see.

To utilize a stock forum meme:


This thread is useless without pics

Silverfox is one smart dude. Consider, too, that sometimes the redbox for focus selection doesn't exactly match the actual focus sensor.

Very rarely do these little imperfections really affect your keeper rate. Try the test above to satisfy your curiosity but go do some tight headshots wide open and see what kind of eyelashes you get. The shot below was with a 135mm L at f2 and 1/160s, at 3200 ISO on a 1D4. No sharpening, even in the crop.

I have a Sigma 50mm f1.4 and it is as good as any other lens I have. There's this other technique that can be employed when you have doubts, it's called manual focus.

HOSTED PHOTO
please log in to view hosted photos in full size.

HOSTED PHOTO
please log in to view hosted photos in full size.

Made me think of this;
http://www.youtube.com​/watch?v=0toBw68L5Y4

muusers wrote in post #12624789
Made me think of this;
http://www.youtube.com​/watch?v=0toBw68L5Y4

ROFLMAO

After reading countless threads about Sigma and Tamron issues, maybe folks should just pony up the extra dollars and buy red rings. At least then there will be satisfaction knowing other photograpers will notice the bright red ring, and make any othere potential issues go away. Not to say the OP doesn't have a legitimate gripe, but I would like to see some real world examples.

LMAO I am sure I was speaking to this guy on here only the other day!

I went thru 3 of those lenses, never got a good one. Maybe you got one of the ones I returned.

rick_reno wrote in post #12624928
I went thru 3 of those lenses, never got a good one. Maybe you got one of the ones I returned.

Now now...don't fuel his fire.

PerfectTan wrote in post #12624938
Now now...don't fuel his fire.

LOL!

kin2son wrote in post #12623935
Any other suggestions?

just use your Canon 50 1.4 - its a very very good lens. focus more in developing your skills as a photographer (composition, lighting, etc....) and worry less about tiny little differences between these lenses and getting "max bokeh, max sharpness".

My Sigma 30mm f1.4 fails battery tests like crazy yet has a 95% keeper rate in the real world. It almost never misses candids, portraits and low light shots - which is what I bought it for. It sucks at battery lines, but luckily that is not a subject I shoot often.

tkbslc wrote in post #12625047
My Sigma 30mm f1.4 fails battery tests like crazy yet has a 95% keeper rate in the real world. It almost never misses candids, portraits and low light shots - which is what I bought it for. It sucks at battery lines, but luckily that is not a subject I shoot often.

This could be a sign of a "distance shift" - I found that my two lenses (135L and Tamron 17-50) need different MFA values for different distances. As lenses are optimized for typical real life distances (and not for the battery test distance), my strong advice is to always test for MFA at real life distances (say, corresponding to half-body portrait, if it is a fast lens, or far away objects if it is UWA landscape lens).

I find nothing wrong with people's desire to test their new lenses for any issues (including AF accuracy) when they still can return it to the store. Learn from my sad experience: I bought my Tamron 17-50 from the cheapest place (no returns), relying on the Tamron's 6-year warranty, found an AF issue right away, but when sent to the Tamron SC, they told me "it's within specs, no need to calibrate".

I just bought one used. I saw sample photos taken with it which were very sharp and the previous user had sent it in to sigma for calibration. However it was off on my body so I just sent it in to sigma again. Mine was wickedly sharp at f/ at my last wedding. But had very slight back focus (tested with focus chart).

entrefoto wrote in post #12625361
I just bought one used. I saw sample photos taken with it which were very sharp and the previous user had sent it in to sigma for calibration. However it was off on my body so I just sent it in to sigma again. Mine was wickedly sharp at f/ at my last wedding. But had very slight back focus (tested with focus chart).

If you don't mind me asking, how much did they say the calibration service would cost?