Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,867   Posts: 1,583,215   Online: 947
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 25
  1. #11
    michaelbsc's Avatar
    Join Date
    Dec 2007
    Location
    South Carolina
    Shooter
    Multi Format
    Posts
    2,106
    Images
    5
    I noticed that you said the 105mm barely has the front standard out on the rails. Don't get too short or you'll end up not able to get infinity.

    You might check the LF board for someone trying to move an old lens, too. They're a little more focused on something like this than APUG. Here there is quite a hodge-podge of stuff to wade through.
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

  2. #12

    Join Date
    Apr 2011
    Shooter
    Multi Format
    Posts
    364
    Quote Originally Posted by michaelbsc View Post
    Don't get too short or you'll end up not able to get infinity.
    I didn't think of that.
    is there a way to calculate the image circle so that I don't end up with something too small? or is it one of those things that varies brand to brand, age to age...

  3. #13
    michaelbsc's Avatar
    Join Date
    Dec 2007
    Location
    South Carolina
    Shooter
    Multi Format
    Posts
    2,106
    Images
    5
    Quote Originally Posted by himself View Post
    I didn't think of that.
    is there a way to calculate the image circle so that I don't end up with something too small? or is it one of those things that varies brand to brand, age to age...
    It varies lens design by lens design. Some long length lenses have small image circles, while some have large ones. Depends on what the lens was designed to do. Likewise, some short focal length designs have small circles while other have large ones, again dictated by the design of what the lens was made to do.

    For example, the 105mm you have in your camera has a relatively small image circle because it was designed for use in a portable camera with little to no movements required. Larger coverage wasn't required, and would have been a waste of money that didn't contribute value to the product.

    Whereas many 90mm and 120mm lenses, both longer and shorter than yours, do have image circles large enough to cover 4x5 because that was part of the design objectives, so the glass was made to do it.

    Ergo, in isolation focal length really tells you very little about the image circle size.
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

  4. #14
    Nicholas Lindan's Avatar
    Join Date
    Sep 2006
    Location
    Cleveland, Ohio USA
    Shooter
    Multi Format
    Posts
    2,381
    Images
    4
    I take it you are looking for a 'Petzval look': sharp center, blurring in the surround, and swirly bokeh.

    http://www.flickr.com/photos/richard...7624453174055/

    If you are on a budget you might want to play around with homemade lenses. Try using the front objective from a set of binoculars, close-up lenses, magnifying glasses, reading glasses. Sometimes removing a corrective element from a decent lens can result in some interesting effects. Try unscrewing the negative element from a triplet or Tessar - use a long focus lens as the starting point; the focal length will shorten when you remove the negative element. You can also try using 1/2 of your Dopple Anastigmat, when one element is removed the focal length will increase as both elements are positive.
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

  5. #15

    Join Date
    Apr 2011
    Shooter
    Multi Format
    Posts
    364
    Quote Originally Posted by michaelbsc View Post
    For example, the 105mm you have in your camera has a relatively small image circle because it was designed for use in a portable camera
    what about the larger plate cameras that cover 9x12?

  6. #16

    Join Date
    Apr 2011
    Shooter
    Multi Format
    Posts
    364
    Quote Originally Posted by Nicholas Lindan View Post
    I take it you are looking for a 'Petzval look': sharp center, blurring in the surround, and swirly bokeh.
    I'm not sure what it's called but selective focus is what I want.

    actually what I originally wanted was a plate camera that could shoot polaroid, but ambition has pushed me beyond that.

    I'll keep in mind what you suggested and if I get hold of any of those things I'll give it a go

  7. #17
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,423
    Images
    2
    Yeah, removing one of the lens elements on the aforementioned Kodak Bausch & Lomb Rectilinear (OTOMH) would increase the focal length as well, so that wouldn't help much I guess.

    How about a close up filter? Again, just an errant suggestion...
    If you are the big tree, we are the small axe

  8. #18
    michaelbsc's Avatar
    Join Date
    Dec 2007
    Location
    South Carolina
    Shooter
    Multi Format
    Posts
    2,106
    Images
    5
    Quote Originally Posted by holmburgers View Post
    Yeah, removing one of the lens elements on the aforementioned Kodak Bausch & Lomb Rectilinear (OTOMH) would increase the focal length as well, so that wouldn't help much I guess.

    How about a close up filter? Again, just an errant suggestion...
    Not only would it "approximatly" double the FL, but it would also substantially increase the image circle. Which is exactly what the OP needs in the short run, a way to test his movements without running out of the circle.

    @himself: Now, keep in mind it isn't going to increase the *AMOUNT OF LIGHT* that's pouring in through the lens. So since the same light will be spread over a circle that's potentially 4 times the area (+/-) you may lose a couple of effective stops.

    Is this making sense? If you can get to them, screw out either the back or the front element of your lens. (I'd take out the back if you can.)

    Then you'll have a lens somewhere in the neighborhood of about 210mm, and your image circle will be a lot bigger. So you can try out your movements, but the image will be dimmer because the available light is spread thinner. Exposure is kind of a guess until you figure out exactly how it's changed.
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

  9. #19
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,423
    Images
    2
    Hmm, but if his FL is doubling (we could all hope to be so lucky) then he's gonna run out of bellows it sounds like.
    If you are the big tree, we are the small axe

  10. #20

    Join Date
    Apr 2011
    Shooter
    Multi Format
    Posts
    364
    Quote Originally Posted by michaelbsc View Post
    Not only would it "approximately" double the FL, but it would also substantially increase the image circle. Which is exactly what the OP needs in the short run, a way to test his movements without running out of the circle.

    [...] Is this making sense? If you can get to them, screw out either the back or the front element of your lens. (I'd take out the back if you can.)
    tried and...

    Quote Originally Posted by holmburgers View Post
    Hmm, but if his FL is doubling (we could all hope to be so lucky) then he's gonna run out of bellows it sounds like.
    he's right, ran out of bellows.

    I managed to drag back the FL with a +2 close up diopter to about 130mm (I can still focus to about half a meter too) and the image circle has increased to a point where I can tilt so much that it's pretty much impossible to focus at all.

    the problem now is that it's completely unusable with a giant filter taped to the front... looks real nice too

    my question now is - can I get a 130mm filter for this shutter?

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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