Need narrow DOF?

Discussion in 'Hot Deals - Find a Great Deal? Share It Here.' started by apicius9, Jan 9, 2011.

  1. apicius9

    apicius9 Mu-43 Veteran

    348
    Feb 1, 2010
    Honolulu, Hawaii
  2. Grant

    Grant Mu-43 Veteran

    Oh my, that is some light bucket!
     
  3. Conrad

    Conrad Mu-43 Veteran

    It doesn't sound right. A max aperture of 50/0.26 and a front lens diameter of 45 mm seems physically conflicting.

    In any way, industrial lenses like this one are usually highly optimized for a very specific magnification and/or wavelength. They can give 'interesting' results when used for photography, but they don't qualify as a general imaging lens.
     
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  4. nseika

    nseika Mu-43 Veteran

    260
    Nov 22, 2010
    Jakarta, Indonesia
    Lois
    Doesn’t understand German. Is “Sill” the name of the manufacturer ?
    What kind of job is this lens originally intended to be used for ?
     
  5. pdh

    pdh Mu-43 Top Veteran

    598
    May 6, 2010
  6. ulugeyik

    ulugeyik New to Mu-43

    6
    Feb 11, 2010
  7. Conrad

    Conrad Mu-43 Veteran

    Thanks for finding the spec sheet.
    :rofl::rofl::rofl:

    This is indeed a fixed magnification telecentric machine vision lens. According to the spec sheet, its design mag is 0.25 (and not the aperture!). The maximum aperture is specified as NA=0.03, or f/16. Probably optimized for LARGE DOF.

    Sometimes we read what we want to read, and not what is meant...
     
  8. pdh

    pdh Mu-43 Top Veteran

    598
    May 6, 2010
    I see that the lens is engraved in large letters 50/0.26, which (conventionally) most of us would read as Focal Length/Maximum Aperture
     
  9. nseika

    nseika Mu-43 Veteran

    260
    Nov 22, 2010
    Jakarta, Indonesia
    Lois
    Thanks.
    Sill is a word, with other meaning (eg: window sill, door sill) so a try in Google doesn't gave the needed answer :)
     
  10. pdh

    pdh Mu-43 Top Veteran

    598
    May 6, 2010
    Quite right, "Sill" is one spelling of "cill",
    I googled for "sill lenses" and "sill correctal", which quickly brought a more useful range of hits
    I'd still be interested to see what sort of image this lens would produce mounted on a :43: camera ...
     
  11. Conrad

    Conrad Mu-43 Veteran

    I guess we all did, at least I did too. Apparently for the application area of this type of lens users are more intersted in the mag than the aperture.

    What I thought was the funny part of this whole story is that somehow the fixation with fast lenses has driven a lot of people (including the seller!) to immediately assume that this was the lens' speed, even though a quick glance at the spec sheet would have told you otherwise. The size is also impressive, which of course adds to the credibility of the assumption, but is not needed for the aperture, but for the telecentricity.
     
  12. RDM

    RDM Mu-43 All-Pro

    This c-mount selling frenzy and price gouging is just so humorous. I remember looking around on the auction sites nine yeas ago. I found an old 16mm camera, without lenses. I actually thought about getting into Making some 16mm movies because the price of the equipment, especially the lenses were so darn cheep. I had picked up a Canon c-mount zoom lens or five bucks. I still have it, and since the micro mount came about I checked to see the same lens selling for several hundred dollars.
    Wish i had a crystal ball back then to tell me all this . I could have gotten lots of fast C-mount lenses for so cheap.