Menu

Exiftool(-k)

GEORGES
2023-02-08
2023-02-10
  • GEORGES

    GEORGES - 2023-02-08

    Good morning,
    I would like to clarify information provided by Exiftool(-k).
    I am using Nikon 610 with AF-S Nikkor 70-300 4.5-5.6G.
    When I made picture, with distance set to infinity, the results show on the exiftool(-k) is for
    - Focal Length 82: Focus Distance 21.13, depth of field 30,82-13,84/44,67, Hyperfocal Distance 39,96
    - For Focal Length 300: Focus distance 21,13, depth of field 1,65-20,34/21,99, Hyperfocal Distance 534,89
    For all cases Subject Distance Range Unknow
    I don’t understand the results shown by Exiftool, which doesn’t match the distance set to infinity !
    I am trying to know the subject distance.
    Is the problem coming from the lens or from Exiftool ?
    Many thanks in advance for your comments.

    Best Regards
    Georges Marre

     
  • Phil Harvey

    Phil Harvey - 2023-02-08

    Hi Georges,

    I don't understand what numbers you are posting, but infinity focus isn't as far away as you might think, especially for short lenses.

     
  • GEORGES

    GEORGES - 2023-02-09

    Hi Phil,
    Many thanks for your answer.
    I will try to explain the numbers posted. There are from Exiftool(-k), as you can see complete copy attached.
    What I am trying to understand is why, when the lens setting is set to infinity I have such number as: depth of field 30,82-13,84/44,67 at 82mm, or depth of field 1,65-20,34/21,99 at 300mm, instead of showing depth of field: inf (…m – inf) !
    I have good results with other lens, showing "inf" when I set to infinity !
    Thanks for your comments.
    Best regards
    Georges

     
  • Hayo Baan

    Hayo Baan - 2023-02-09

    Hi Georges,

    The numbers exiftool returns are simply what the camera (and lens) reports in the metadata. And as Phil already pointed out, “infinity” isn't the same for all lenses. For this lens, it looks like infinity is actually 21.13 meter (focus distance in both cases is 21.13m).

    The numbers for depth of field and hyperfocal distance are calculated values, based on the focus distance, circle of confusion, aperture and are purely theoretical values.

    Does this help in understanding what's going on?

    Cheers,
    Hayo

     
  • GEORGES

    GEORGES - 2023-02-09

    Hi Hayo,
    Thank you for this explanation, which give me a new light on the subject.
    Taking into consideration “infinity” isn't the same for all lenses, and for my lens AF-S VR Zoom-Nikkor 70-300 f/4.5-5.6G IF-ED, it seems to be 21.13m for infinity !
    Does anyone, know the origin of this number for this lens? and correlation with infinity ?
    Thanks for your comments.
    Best regards
    Georges

     
  • Hayo Baan

    Hayo Baan - 2023-02-09

    Hi Georges,

    The origin of the number is the lens itself – it's what it reports to the camera – and is defined by the physics of the lens; it's design does not let it focus further than that (at least that's how I read it). Also, these numbers can not be taken as absolute truths at all. Fabrication differences (even within tolerances), temperature, etc. all make the numbers indicative at best.

    Note: I don't know how on the mark above statements are. They are simply built on logical reasoning and some knowledge of the physics of things. I have no inside knowledge that tells me what the numbers exactly mean 😉

    Cheers,
    Hayo

     
  • GEORGES

    GEORGES - 2023-02-10

    Hi Hayo,
    Many thanks for your explanations.
    Best regards
    Georges

     

Log in to post a comment.

Want the latest updates on software, tech news, and AI?
Get latest updates about software, tech news, and AI from SourceForge directly in your inbox once a month.