Sigma 18-50 EX Macro arrives... problems

My shiny new lens arrived today, and unfortunately I think there's quite a severe problem. I'm not the most expert guy on these things but if I had to guess I'd say it was front focusing like a mofo:


Focus (using center focus point) was on the brown splotch surrounded by white about in the center of the frame:

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i would suggest shooting something else straight on vs at a left angle like that, try shooting a person, or a leaf on a tree. or hell even a focus chart.

That's pretty severe, I agree. Definitely do one or the other...that's unacceptable.

I have never had any issues with Sigma lenses (knock on wood), so I have no service experiences to share...sorry.

turbodude wrote in post #5674030
i would suggest shooting something else straight on vs at a left angle like that, try shooting a person, or a leaf on a tree. or hell even a focus chart.

I agree...just to verify your results, it would be wise to test on a high-contrast object.

I have a question, as I do more testing, if a lens is indeed 'front focusing', does it also jack up the MANUAL focus?


I'm having a hard time even getting a decent MF shot it seems. Totally bizarre... and I've never experienced anything like this before.

definatly not. you should still be able to manual focus, are you sure its not user error

gorby wrote in post #5674067
I have a question, as I do more testing, if a lens is indeed 'front focusing', does it also jack up the MANUAL focus?

I'm having a hard time even getting a decent MF shot it seems. Totally bizarre... and I've never experienced anything like this before.

No...it's a CPU issue in the lens.

Yes, I'm sure it's not user error. I know how to manual focus a lens. Here are some tests with the camera mounted on a tripod:

Here's full crop @ 50mm f/2.8

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what was the exif on it?

On the first DVD shot?

50mm f/2.8

iso 100

1/25

yea because nopthing in that shot seems to be in focus, was this handheld or on a tripod?

Tripod... all the DVD shots were. They were all taken with the timer function so I didn't have to press the shutter.

Case closed...return the lens or send it to sigma to fix.

Closed indeed, I was so looking forward to this lens

Already printed the return label...

gorby wrote in post #5674751
Closed indeed, I was so looking forward to this lens

Already printed the return label...

I feel yah... I loved my sample, but sometimes you have bad luck. That's why warranties were invented.