Results 1 to 8 of 8

Thread: Focal length for 50mm lense

  1. #1

    Default Focal length for 50mm lense

    Hi, I am using a newbie and trying out a 50mm lense, when I'm using auto focus, I can't focus on the subject if its less than 1.5m, but my 50mm focal length is 0.45m, have I missed out any setting? Thanks.

  2. #2
    Member CasualBear's Avatar
    Join Date
    May 2013
    Location
    singapore
    Posts
    485

    Default

    1. Go search focal length on camera lens..
    2. Read the stickies articles on newbie section.. this should b sufficient..
    Leave nothing but footprints, take nothing but photos..~ ;)

  3. #3

    Default Re: Focal length for 50mm lense

    Quote Originally Posted by bluebaby View Post
    Hi, I am using a newbie and trying out a 50mm lense, when I'm using auto focus, I can't focus on the subject if its less than 1.5m, but my 50mm focal length is 0.45m, have I missed out any setting? Thanks.
    The focus length of 50 mm lens is 50 mm.

    I think you mean the lens minimum focus distance is 0.45 m

    If there are insufficient light, you will also have problem focusing.

    You may want to switch to Aperture priority mode and set aperture to F1.8 or F1.4
    I eats, shoots & leaves

  4. #4
    Moderator daredevil123's Avatar
    Join Date
    Oct 2005
    Location
    lil red dot
    Posts
    21,627
    Blog Entries
    1

    Default Re: Focal length for 50mm lense

    Quote Originally Posted by Yutaka Go View Post
    You may want to switch to Aperture priority mode and set aperture to F1.8 or F1.4
    For modern cameras, aperture setting has nothing to do with auto focus speed.

  5. #5

    Default

    Quote Originally Posted by bluebaby View Post
    Hi, I am using a newbie and trying out a 50mm lense, when I'm using auto focus, I can't focus on the subject if its less than 1.5m, but my 50mm focal length is 0.45m, have I missed out any setting? Thanks.
    Please read up on the difference between focal length and minimum focus distance. They are not the same thing.
    Alpha

  6. #6
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: Focal length for 50mm lense

    Quote Originally Posted by bluebaby View Post
    Hi, I am using a newbie and trying out a 50mm lense, when I'm using auto focus, I can't focus on the subject if its less than 1.5m, but my 50mm focal length is 0.45m, have I missed out any setting? Thanks.

    I think you mixed up minimum focusing distance aka closest focusing distance with focal length.

    http://en.wikipedia.org/wiki/Canon_EF_50mm_lens

    anyway, it could be you are shooting in low light, or the subject has no contrast, or too tiny, so the camera unable to do auto focus.
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  7. #7
    Member Mythmaker's Avatar
    Join Date
    Oct 2011
    Location
    Buangkok MRT
    Posts
    1,011

    Default Re: Focal length for 50mm lense

    It's more to do with your shooting I think. When you go close (in your case, lower than 1.5m), everything becomes bigger. When things are bigger, finding a spot that has contrast is tougher. You need that contrast for AF to lock on. You just can't randomly pick a spot and pray it will focus on.

  8. #8
    Moderator rhino123's Avatar
    Join Date
    Sep 2006
    Location
    NA
    Posts
    5,247

    Default Re: Focal length for 50mm lense

    Quote Originally Posted by bluebaby View Post
    Hi, I am using a newbie and trying out a 50mm lense, when I'm using auto focus, I can't focus on the subject if its less than 1.5m, but my 50mm focal length is 0.45m, have I missed out any setting? Thanks.
    1) What subject are you focusing on?
    2) Have you try manual focusing, if yes, can you get a sharp focus?
    3) Set your camera + lens on a tripod and take your time to 'test' focusing on different subject at less than 1.5m (subject like pebbles, flowers, cactus or even yourself), see if there is a problem with locking focus on all these subjects or was the camera seemingly 'selective' locking on.

    If you tried different subjects, some can lock on focus, some cannot, then most probably, it might be those subject that you are shooting are very low in contrast with the surrounding (e.g a blank piece of white paper). If everything also cannot focus, then it might be some issue with your lens and you might want to bring it down to the service centre.
    I am not a photographer, just someone who happened to have a couple of cameras.
    My lousy shots

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •