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Sigma dock - recommended distance settings?
  
 
leethecam
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p.1 #1 · p.1 #1 · Sigma dock - recommended distance settings?


Just treated myself to the Sigma 50mm Art + the dock.

My base micro focus setting will be at 50x focal length - so 2.5m

Which leaves me with 3 other distances that I can tune micro focus to.

What might be useful distances to select? How much flexibility do I have in this respect with distance selection? Do the offsets on the dock relate in any way to the offsets on my Canon 5D3 ?

I'll be playing with it all tomorrow but good to have a heads up beforehand.

If there are any tips for using the dock, I'm all ears.



Feb 21, 2017 at 09:54 PM
tiggy
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p.1 #2 · p.1 #2 · Sigma dock - recommended distance settings?


The sigma dock system requires that you conduct focus tests at very, very specific distances. You'll see it in the software. I made the mistake of initially guestimating the distances, and the results were terrible. There needs to be quite a bit of precision, I found, to get excellent results. But it's well worth it.

The equations that your adjustment numbers are plugged into appear to be complex formulae that are not the simple, graduated effect that you see with Canon zooms. Where the Canon figures appear to be a simple sliding of one adjustment figure to the next over the course of the focal length, the Sigma figures are much more volatile. I suspect they are parabolic equations.

I just had my 50mm out tonight taking pictures of the kids. Every time I do this, I shake my head and wonder why I use other lenses so often. You'll love it.

PS: A plug for Sigma build quality. I dropped my 50 Art on the concrete garage floor last week. Previously, it rolled off a table onto a wooden floor. The thuds it makes in these circumstances are toe curling. But it just keeps on rocking on. Tested it to see if I needed to re-AFMA it, but nope, it's just drinking in light like it did before. There is a dent in my cherry, floor, however. That composite they use in construction is very, very tough stuff. I doubt a metal lens would have absorbed so much energy and protected the glass elements. Someone buying this used would not be terribly pleased by the scratches on the outside. Looks like I'm keeping it for life.



Feb 22, 2017 at 03:30 AM
dalite
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p.1 #3 · p.1 #3 · Sigma dock - recommended distance settings?


That's amazing tiggy. Did the dropped lens have a hood on and did the hood make contact with the cherry floor?


Feb 25, 2017 at 04:58 AM







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