Results 1 to 1 of 1

Thread: Lazy bellows extension factor...

  1. #1

    Join Date
    Jul 2004
    Location
    Tucson, Arizona
    Posts
    4,183

    Lazy bellows extension factor...

    I'm kinda cross-posting this from another thread, just 'cause I thought it was nifty, and I never heard anyone mention this technique before...

    There are a number of ways to figure bellows extension factor. Personally, I just divide the bellows extension by the aperture diameter and there's your f/stop.

    But if you're reeeeally lazy, set your f/stop to one inch and measure the bellows extension in inches. Or set it to one centimeter and measure the bellows extension in centimeters. Then you're just dividing by one; you bellows extension is your f/stop.

    See this lens currently on ebay, #330714904774:



    Notice it's got a big white mark at about f/11? Let's check one of my old Velostigmats and see what that measures to be...



    Hmmm... about an inch. (Remember, there can be a little slop in the iris accuracy, just like on shutter times.) There once was an old photographer who had the option of measuring his bellows extension, and that was his f/stop, period. 18 inches of extension? f/18. 14 inches? f/14. 26 inches? f/26.

    I can't swear that this is what was going on, but I've seen a few shutters marked this way, and it's always one inch, sometimes also at half an inch (easy math, cut your extension in half!), or one centimeter. If you aren't fussy about your taking aperture, it can make life easy.

    Today's photo-tip for lazy math-phobes!
    Last edited by Mark Sawyer; 9-Apr-2012 at 20:00.
    "I love my Verito lens, but I always have to sharpen everything in Photoshop..."

Similar Threads

  1. How to calculate bellows extension from the bellows factor?
    By Cor in forum Cameras & Camera Accessories
    Replies: 18
    Last Post: 4-Mar-2011, 11:13
  2. Bellows factor
    By Steve M Hostetter in forum Style & Technique
    Replies: 41
    Last Post: 9-Jan-2009, 12:00
  3. Bellows factor for telephoto lenses?
    By Arne Norris in forum Style & Technique
    Replies: 6
    Last Post: 15-Jan-2008, 13:33
  4. Bellows factor question
    By Rich Lingg in forum Gear
    Replies: 5
    Last Post: 24-May-2000, 21:26
  5. Formula for bellows factor
    By Bryan Fleishman in forum Style & Technique
    Replies: 3
    Last Post: 8-Jan-1999, 14:12

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
  •