Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,904   Posts: 1,584,587   Online: 911
      
Page 1 of 4 1234 LastLast
Results 1 to 10 of 39
  1. #1

    Join Date
    Feb 2012
    Location
    Alamo City, USA
    Shooter
    Multi Format
    Posts
    1,884

    I FINALLY Understand... Bokeh & Aperture Roundness

    It finally "clicked" in my diseased old brain.


    I've often pondered the elusive "creaminess" of the out-of-focus areas of some lenses. What appeals strongly to me are sharp highly corrected high-contrast lenses with lots of aperture blades. None of my modern lenses have such an aperture. They all have the typical out-of-round apertures.


    I DO realize there are other qualities that differentiate modern lenses from classic but... it's ONLY the round apertures that interest me.


    Are there modern shutters into which I can transfer my #0, #1, and #3 sized cells? I realize I'll need new scales. That's okay.

    BTW, I don't need flash sync.
    Last edited by Old-N-Feeble; 04-02-2012 at 04:29 PM. Click to view previous post history.

  2. #2

    Join Date
    Nov 2005
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    5,277
    Mike, I think the days of lots of aperture blades ended in the 1950's or 1960's.

  3. #3

    Join Date
    Nov 2005
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    5,277
    You might be able to find some later Compur shutters and swap your modern cells into them.

  4. #4

    Join Date
    Feb 2012
    Location
    Alamo City, USA
    Shooter
    Multi Format
    Posts
    1,884
    Thanks... I'll search for Compur shutters.

  5. #5

    Join Date
    Nov 2005
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    5,277
    My experience, though, is that the lens bought in an older Compur shutter is just as good as a newer lenses.

  6. #6
    Maris's Avatar
    Join Date
    Jan 2006
    Location
    Noosa, Queensland, Australia.
    Shooter
    Multi Format
    Posts
    752
    Round apertures are available for all lenses merely by using lenscaps with nicely made holes in them.

    With normal and long focal lengths the problem of vignetting tends not to arise but wide-angle lenses (particularly retrofocus designs) need testing individually. But why stop with round apertures. Try squares, triangles, stars, flowers and so on. Years ago I did a portrait shoot with a lens masked with black paper bearing the cut-out initials of the subject. The final picture repeated those initials in every out of focus specular highlight!
    Photography, the word itself, invented and defined by its author Sir John.F.W.Herschel, 14 March 1839 at the Royal Society, Somerset House, London. Quote "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..". unquote.

  7. #7
    Nicholas Lindan's Avatar
    Join Date
    Sep 2006
    Location
    Cleveland, Ohio USA
    Shooter
    Multi Format
    Posts
    2,381
    Images
    4
    Bokeh has little to do with the shape of the aperture (within reasonable limits, of course).

    A lens with unacceptable bokeh with a 5 or 7 blade aperture will have unacceptable bokeh with a perfectly round aperture.

    Interestingly a lens that has terrible bokeh for things that are more distant than the focus point will have wonderful bokeh for things that are nearer.
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

  8. #8
    John Austin's Avatar
    Join Date
    Oct 2010
    Location
    Southern Forest Region, Western Australia
    Shooter
    Large Format
    Posts
    521
    Blog Entries
    3
    Bokeh* as I understand it is a function of the way spherical aberration is corrected, or not - The following chart is the best description of Bokeh I have yet found - It is from the 1897 book by Conrad Beck

    Click image for larger version. 

Name:	bokeh.jpg 
Views:	94 
Size:	174.7 KB 
ID:	48840

    However, a modern aperture will give a funny shaped circle, but as good bokeh is considered to be smooth with circles of out of focus light shown without a harsh edge that becomes less of a problem - When looking for lenses for LF the OOF zones are a deciding factor in my decision, one of the reasons I like my Heliars**

    * "Bokeh" is too trendy a term and like everything else they name the Japanese did not discover or invent it, proof of which is the Beck illustration

    ** The failings of Heliars is subject for another discussion which I am sure has happened in the past - To me it is a problematic design which perfectly suits some subjects - I do not use my Heliars for landscape photography and prefer my better balanced Skopar, Xenar and Ysarex designs

    Now to scan last week's images for email proofs to a client before the big silver jelly prints get made - After that I get the money which will all go to a dentist for some crowns - One of the joys of aging

    John
    Last edited by John Austin; 04-02-2012 at 06:10 PM. Click to view previous post history.

  9. #9

    Join Date
    Feb 2012
    Location
    Alamo City, USA
    Shooter
    Multi Format
    Posts
    1,884
    I think, with the highly-corrected modern lenses I'll be using, that aperture roundness is the limiting factor. Would it help if I listed the lenses?

  10. #10
    John Austin's Avatar
    Join Date
    Oct 2010
    Location
    Southern Forest Region, Western Australia
    Shooter
    Large Format
    Posts
    521
    Blog Entries
    3
    No need for a list - Look through a backlit tree and see how the OOFs appear - Then visit as many other LF photographers and do the same with their lenses - After that make your lens set decisions - Many older designs had a better balance of corrections and this balance seems to have been lost in the thrust for sharpness at the loss of equally important properties

Page 1 of 4 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin