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I have a 55-210 zoom lens, and the specs show that the minimum focus distance is 1m. Does that distance remain constant if I use the zoom? Or does that change it? Thanks in advance!

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  • \$\begingroup\$ Related: How do focal length, minimum focus distance, and magnification interact on a lens? \$\endgroup\$
    – Michael C
    Commented Jan 5, 2019 at 4:26
  • \$\begingroup\$ Why do you not just focus on something a meter away and change zoom? If it goes out of focus then you know MFD changes for your lens. \$\endgroup\$
    – xiota
    Commented Jan 5, 2019 at 10:10
  • \$\begingroup\$ Xiota, that's the thing... I bought this new lens, and the autofocus is inconsistent at various distances (from 1m to 3m) when I'm using the zoom. I'm trying to figure out if the lens is defective. There is also a possibility that my camera itself needs servicing, as it acts up with an older lens that I have. So many factors here and I'm trying to rule some out. \$\endgroup\$
    – user81053
    Commented Jan 5, 2019 at 15:42
  • \$\begingroup\$ It's not surprising for MFD to change across then zoom range. All my variable aperture zooms do. I haven't checked the constant aperture ones. \$\endgroup\$
    – xiota
    Commented Jan 5, 2019 at 16:58
  • \$\begingroup\$ Also any zoom lens that says "macro" with have variable min focusing distance because macro mode is usually at one end of the zoom range. \$\endgroup\$
    – xiota
    Commented Jan 5, 2019 at 17:00

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It ultimately depends on the design of the specific lens model (which you have not provided). Most, but far from all, telephoto zoom lenses have roughly the same MFD over their entire focal length range. But there are plenty of exceptions.

Most folks are concerned with MFD primarily with regards to how it affects maximum magnification. For the vast majority of zoom lenses, MM and MFD are both found at the longest focal length, so that's all most lens makers tend to publish in their specs.

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  • \$\begingroup\$ Thanks, got it! It is a Sony SEL 22510. I also have the original Sony kit lens 18-55mm for the NEX 5-R. \$\endgroup\$
    – user81053
    Commented Jan 5, 2019 at 4:30
  • \$\begingroup\$ @Mooshi Do you mean SEL 55210? \$\endgroup\$
    – Michael C
    Commented Jan 5, 2019 at 4:45
  • \$\begingroup\$ Ahahahaha. Yes. \$\endgroup\$
    – user81053
    Commented Jan 5, 2019 at 4:49

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