Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 25

Thread: Process lens image circle nature

  1. #11

    Join Date
    Jul 2016
    Posts
    4,334

    Re: Process lens image circle nature

    Quote Originally Posted by erian View Post
    I am planning to buy my first large process lens and I am wondering how does various process lenses image circle behave. Is it quick cut off or more gradual fade?

    I am considering something around 750-800mm range and I plan to use it for portraiture (i.e. 1:1).
    My LOMO O-2 600mm, a dyalite type, covers 41 in the specs but it illuminates around 90, with increasing softness when going beyond the specified coverage circle.

    Illumination circle of APO-Nikkors are also reportedly very big: https://www.largeformatphotography.i...ll=1#post56941

    So for your application they may work, as you may have the corners in the out of focus, still you will have fall-off in the outer illumination boundary.

  2. #12
    Vaughn's Avatar
    Join Date
    Jan 2007
    Location
    Humboldt County, CA
    Posts
    7,405

    Re: Process lens image circle nature

    Quote Originally Posted by erian View Post
    I plan to build a camera obscura. The one where you can walk in. I plan to focus by moving the back inside the camera. I am thinking to use large photo paper and by large I mean really large like 1 meter by 60 cm or similar.
    Cool! Vacuum frame? That would also be cool, but a bit of extra work. Have fun!
    "Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China

  3. #13

    Join Date
    Sep 2017
    Posts
    131

    Re: Process lens image circle nature

    Quote Originally Posted by Pere Casals View Post
    My LOMO O-2 600mm, a dyalite type, covers 41 in the specs but it illuminates around 90, with increasing softness when going beyond the specified coverage circle.

    Illumination circle of APO-Nikkors are also reportedly very big: https://www.largeformatphotography.i...ll=1#post56941

    So for your application they may work, as you may have the corners in the out of focus, still you will have fall-off in the outer illumination boundary.
    Nice, this is exactly what I was looking for.

    Does anybody know this about Ronars and Artars?

  4. #14

    Join Date
    Sep 2017
    Posts
    131

    Re: Process lens image circle nature

    Quote Originally Posted by Vaughn View Post
    Cool! Vacuum frame? That would also be cool, but a bit of extra work. Have fun!
    I thought about this on my way home today. How to keep vertical junk of paper flat. Yes, vacuum would do put I thought that it definitely will not fit into thigh time frame. I have about a week to build and use this (in addition to other Christmas activities).

  5. #15
    Tin Can's Avatar
    Join Date
    Dec 2011
    Posts
    13,210

    Re: Process lens image circle nature

    One week!
    ,
    Use what you got, no vacuum, tape it up, use longest LF lens you have, use a hat for a shutter as paper is very low ISO, like 2 to 5 ASA which is the same almost as ISO.

    If it's a family pic, do it after they all fall asleep and are not moving. The exposure may be very long.

    No lens, use a pinhole and even longer exposure, Go here, https://www.mrpinhole.com/

    Post the results here no matter what it looks like.

    Repeat yearly.

    Merry Christmas!

    Out

    Quote Originally Posted by erian View Post
    I thought about this on my way home today. How to keep vertical junk of paper flat. Yes, vacuum would do put I thought that it definitely will not fit into thigh time frame. I have about a week to build and use this (in addition to other Christmas activities).
    sin eater

  6. #16

    Join Date
    Jan 2012
    Location
    Beijing
    Posts
    195

    Re: Process lens image circle nature

    Quote Originally Posted by erian View Post
    I thought about this on my way home today. How to keep vertical junk of paper flat. Yes, vacuum would do put I thought that it definitely will not fit into thigh time frame. I have about a week to build and use this (in addition to other Christmas activities).
    For a temporary camera, I'd just use low stick spray adhesive on the back of the paper.

  7. #17

    Join Date
    Jul 2016
    Posts
    4,334

    Re: Process lens image circle nature

    Quote Originally Posted by erian View Post
    this about Ronars and Artars?
    Ronars and Artars are also dyalites, with similar behaviour.

  8. #18

    Join Date
    Sep 1998
    Location
    GA
    Posts
    12,724

    Re: Process lens image circle nature

    Quote Originally Posted by Pere Casals View Post
    Ronars and Artars are also dyalites, with similar behaviour.
    How about Apo Gerogons?

  9. #19

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    7,568

    Re: Process lens image circle nature

    Quote Originally Posted by Bob Salomon View Post
    How about Apo Gerogons?
    If you'd read this discussion from the beginning you'd know that the longest Apo-Gerogon is too short for the OP's project.

  10. #20

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    7,568

    Re: Process lens image circle nature

    Quote Originally Posted by Pere Casals View Post
    Ronars and Artars are also dyalites, with similar behaviour.
    There are dialyte type Apo-Nikkors, too.

Similar Threads

  1. Curious Minds Image Circle, Circle of Illumination, ULF, and Contact Prints
    By Len Middleton in forum Lenses & Lens Accessories
    Replies: 15
    Last Post: 25-Mar-2013, 09:51
  2. Image circle for 270mm f10 Nikon Process
    By Herb Cunningham in forum Lenses & Lens Accessories
    Replies: 3
    Last Post: 31-Mar-2008, 13:26
  3. Image circle on process lenses
    By Herb Cunningham in forum Lenses & Lens Accessories
    Replies: 1
    Last Post: 19-May-2007, 11:47
  4. image circle of Nikkor Apo 455mm f9 process lens
    By Herb Cunningham in forum Lenses & Lens Accessories
    Replies: 7
    Last Post: 25-Sep-2003, 22:55
  5. How to tell the image circle size of a lens?
    By Ron Whitaker in forum Lenses & Lens Accessories
    Replies: 1
    Last Post: 27-Sep-1999, 21:33

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
  •