w w w . i n d i a w i l d s . c o m
home
about Sabyasachi Patra
diary
forums
image gallery
contact IndiaWilds
Home
About
Diary
Forums
Gallery
ContactUs

User Tag List

Results 1 to 6 of 6

Thread: Auto focus function with Canon 1.4X III extender

  1. #1
    Join Date
    23-02-09
    Location
    Bangalore
    Posts
    113
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Default Auto focus function with Canon 1.4X III extender

    Hi. If I use a 1.4X (mark 3 latest) extender with an L series 100-400 4.5-5.6 EF lens of canon, will I lose the auto focus function? Thanks for any input.

  2. #2
    Join Date
    24-11-08
    Location
    New Delhi
    Posts
    16,591
    Mentioned
    0 Post(s)
    Tagged
    2 Thread(s)

    Default

    When you use the 100-400 lens with a 1.4x TC, the aperture becomes f8. So you will lose auto focus function with all cameras except the 1 series cameras. In the 1 series cameras (except the yet to be launched Canon EOS 1DX), you can use the centre AF point to auto focus. If I remember right you were using a 7D. In the EOS 7D camera, you will lose auto focus and have to manually focus if you use the 1.4x (I, II, III versions).

  3. #3
    Join Date
    23-02-09
    Location
    Bangalore
    Posts
    113
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Default Thanks

    Thanks a lot. I am told that we have to mask 3 pins using a tape so that auto focus will work on 7D..


    Quote Originally Posted by Sabyasachi Patra View Post
    When you use the 100-400 lens with a 1.4x TC, the aperture becomes f8. So you will lose auto focus function with all cameras except the 1 series cameras. In the 1 series cameras (except the yet to be launched Canon EOS 1DX), you can use the centre AF point to auto focus. If I remember right you were using a 7D. In the EOS 7D camera, you will lose auto focus and have to manually focus if you use the 1.4x (I, II, III versions).

  4. #4
    Join Date
    23-02-09
    Location
    Bangalore
    Posts
    113
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by Sabyasachi Patra View Post
    When you use the 100-400 lens with a 1.4x TC, the aperture becomes f8. So you will lose auto focus function with all cameras except the 1 series cameras. In the 1 series cameras (except the yet to be launched Canon EOS 1DX), you can use the centre AF point to auto focus. If I remember right you were using a 7D. In the EOS 7D camera, you will lose auto focus and have to manually focus if you use the 1.4x (I, II, III versions).
    It works as follows:

    http://www.michaelfurtman.com/taping_the_pins.htm

  5. #5
    Join Date
    24-11-08
    Location
    New Delhi
    Posts
    16,591
    Mentioned
    0 Post(s)
    Tagged
    2 Thread(s)

    Default

    The pin taping is a popular trick which works well for some and not so well for others. If you are in a safari, then better to rest the lens on the vehicle and use the manual focus ring to fine tune the focus.

  6. #6
    Join Date
    23-02-09
    Location
    Bangalore
    Posts
    113
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Default

    Thanks Sabs. I learnt another thing. I am using a 1.4X mark III extender of canon. When i mask the three pins, auto focus slows down but aperture does not drop !!! Picture quality is excellent.

    If i don't mask then auto focus goes away and aperture drops by 1 stop.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Posting Permissions

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