LSXPhotog,
you sounds like a very reasonable person. thank you for your input and clarification.
the focus drift issue you are referring to I cannot comment about as i do not have much clients coming back for a second AFMA run. it may well be the case due to the lens being such a behemoth. I actually would like to thank you for this information. it is great to know.
you are absolutely correct. you cannot afford adjusting and re adjusting the lens so many times. this behaviour alone negates the whole purpose of owning the Sigma. I totally appreciate what you are saying. the point is taken.
you sounds like a very reasonable person. thank you for your input and clarification.
the focus drift issue you are referring to I cannot comment about as i do not have much clients coming back for a second AFMA run. it may well be the case due to the lens being such a behemoth. I actually would like to thank you for this information. it is great to know.
you are absolutely correct. you cannot afford adjusting and re adjusting the lens so many times. this behaviour alone negates the whole purpose of owning the Sigma. I totally appreciate what you are saying. the point is taken.
LSXPhotog said:SecureGSM said:LSXPhotog, as you suggested "... The Sigma may have back-focused slightly in this shot.." and it happens a lot for you apparently. if that is consistent then you need to AFMA your lens properly, I mean properly.
there is no point in comparing of Sigma OOF shots with Canon in focus shots. can you please take couple of shots in Live View mode. thanks.
p.s. in Axial CA example Sigma is definitely out of focus. back focused again. there is a tell tale sign when it does. and Sigma is actually significantly worse in your example. just so that you are aware.
My Sigma 85mm Art has LIVED on the USB dock for better parts of the year. When I got the lens, it seemed to be pretty damn spot on, so I didn't touch it. After my first long race event shooting with it, I had several shots that were off. So I spent a good portion of time getting it dialed in with a FoCal Lens Cal target and it was working really well. Then, after a month or two, it suddenly seemed that I wasn't getting sharp focus again, so I put it back on. Rinse and repeat. I've been doing this every few months and I'm basically done with this lens in general as a result of the autofocus. The only thing consistent about it is its inconsistency. There's no rhyme or reason to when and where or what focus distance it will miss on, the lens misses. Also understand that I'm very strict on what I consider "acceptable" and throw away anything where a nose is sharp, but the eyes aren't.
Tomorrow I plan to do more tests with the lens. For determining critical sharpness, I will indeed be using live view. But in the real world, I don't walk around like a dink using live view to photograph professional work - is use it here and there, but I shoot 95+% of my work through the viewfinder...
I really don't understand why you're defending Sigma so much? I have owned the 50mm Art and 85mm Art since the day they came out. They're truly incredible pieces of glass, but for what I do and how I use gear, I can't keep the 85mm in my bag. The 50mm I use for isolated detail work and occasional portraits where it works just fine. But 85mm is too important.
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