Page 1 of 3 123 LastLast
Results 1 to 10 of 21

Thread: Process lens image quality

  1. #1

    Join Date
    Feb 2005
    Posts
    2,955

    Process lens image quality

    I know very little about process lenses, but I imagine they are optimised for 1:1. How do they perform at infinity?

  2. #2

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    8,467

    Process lens image quality

    Um, to anticipate a little, when Bob Salomon notices this thread he'll tell you that when taking pictures of subjects at distance you're best off using a lens designed to do that. By him, process lenses shot at distance are second-best. I believe that this is Bob's personal view and that it does not reflect his commercial interests.

    Nikon's literature on their process lenses (Apo-Nikkor, Process-Nikkor, some but not all Nikkor-Qs) says that they are best from 3:1 to 1:3 and good at all distances.

    Rodenstock's propaganda on Apo-Ronars asserts that an AR is better at distance than the equivalent tele lens.

    The lens books agree that dialyte type lenses optimized for 1:1 hold their corrections very well at all distances. They suggest that asymmetrical lenses like tessar types optimized for 1:1 should be worse at distance. My Taylor Hobson tessar type copy lenses don't agree with the books.

    In my limited experience, process lenses do well at distance. But much depends on condition, and many of them are very hard to put in shutter. Two sets of problems there. The cells aren't always threaded to go into standard shutters, require expensive adapters. And sometimes extracting the cells from their barrel isn't easy. I finesse those problems by hanging 'em in front of a shutter. This works for me because I shoot 2x3, might not always work with larger formats.

    If you're contemplating buying a process lens and then putting it in shutter, estimate the costs as best you can before buying. It often turns out that a relatively modern used lens of the same focal length in shutter will cost less.

  3. #3

    Join Date
    Dec 1997
    Location
    Baraboo, Wisconsin
    Posts
    7,697

    Process lens image quality

    I've used four different G Clarons and one APO Artar. All performed well at any distance. It may be desirable for some specialized purposes (e.g. macro photography) to try to match the distance for which a lens is optimized to a particular subject distance but I don't think that's necessary for most purposes. I use whatever focal length lens is needed for the desired composition and never think about whether I'm within the distance for which the particular lens is optimized. There are so many variables involved in making a technically excellent photograph that I don't think they can all be dealt with to perfection. Operator ability/talent/knowledge is IMHO much more important than owning the perfect equipment for every possible purpose.
    Brian Ellis
    Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
    a mile away and you'll have their shoes.

  4. #4
    Abuser of God's Sunlight
    Join Date
    Aug 2004
    Location
    brooklyn, nyc
    Posts
    5,796

    Process lens image quality

    I've seen a lot of work done by friends with process lenses (including older ones like apo tessars and kodak copying ektanons). They seem to make beautiful, crisp contact prints. Looking at negs with a loupe, though, it's clear that at any significant magnification they'd be soft.

    If you go to the schneider site and look at g-claron MTF curves, you'll see that they are not sharp lenses (by the standard of general purpose lenses) a higher resolutions or at infinity.

  5. #5

    Join Date
    Mar 1999
    Posts
    769

    Process lens image quality

    Yes, many process lenses are optimised for close distances but the corrections of the dialyte design that they are based on are supposedly fairly robust to a wide variety of distances. That is, the corrections are not terribly upset by using them at distances they are not optimised for. In short, while there may be a theoretical drop in performance when you use them at infinty, the drop is not bad and based on practical experience of many, they perform admirably at infinty. Cheers, DJ

  6. #6
    Ted Harris's Avatar
    Join Date
    Aug 2000
    Location
    New Hampshire
    Posts
    3,465

    Process lens image quality

    I have never done any exact optical measurements of 'process lenses' bu tI use the Fuji A series 240mm and 300mm lens and, like many others, find them among the best lenses in my kit. The 300, particularly, is one of my all time favorite lenses for landscape work. I also use a Docter Apo Germinar 3650mm lens (also a process design) that performs wonderfully at infinity for landscape work.

    I think you willfind that most folks have similar experiences.

  7. #7

    Join Date
    Mar 2005
    Location
    Pasadena, CA
    Posts
    389

    Process lens image quality

    Hey Ted -

    Ahem... You have a 3650mm ( 143.7 inch, or about 12 foot lens??? )

    This is amazing! I'd like to borrow it from you sometime. Is it faster than f2800?

    I'd like to build a nice "tow and shoot" camera for it. How big
    is the image circle on it, and does anyone know where to get a 12 foot wide
    roll of film made up? <big grin> Perhaps it would be better to just make
    some giant tintypes or glass plates...

  8. #8

    Join Date
    Aug 2001
    Location
    Vancouver
    Posts
    373

    Process lens image quality

    Ed, in my experience the fact that the 3650mm lens is two stops slower doesn't make a difference in focusing on the ground glass. Depth of field, which is limited with the 2800 as you know, is nonexistent with the 3650, so choose your subject carefully. The real problem is that when stopped down to the optimal aperture of f/2680, it doesn't let in any light. But when you see the final results on paper, and when people comment "that single eyelash that's in focus is really pretty," it makes the back surgery for the slipped disk seem like a small price to pay.

    But seriously, Ron, I had the same question a while back. I've never seen back to back comparisons of a process lens to a plasmat or other design, but looking at the beautiful prints of Michael Smith & Paula Chamlee, many of which were made with old Goerz Red Dot Artars, and it's clear to me that you won't be disappointed with a process lens for distant subjects. If Bob Salomon is here, could you provide a link to photos taken with a plasmat vs a process lens at low reproduction ratios? That would be great to illustrate the point.

  9. #9
    Ted Harris's Avatar
    Join Date
    Aug 2000
    Location
    New Hampshire
    Posts
    3,465

    Process lens image quality

    Ed, LOLOLOL ... ahh those cold fingers! Welllll, I'll sell it to you for only 50¢ a mm. A bargain at twice the price ....

  10. #10

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    8,467

    Process lens image quality

    Guys, after I shot my 180/10 Apo-Saphir against my 7"/4.5 Aviar, post-WWII and coated and beautiful, I sold the Aviar. The Aviar is, I've read, legendary for all sorts of good qualities. But understand that for me coverage is unimportant even with lenses as short as those because I stick with tiny little 2x3.

    I've reported many times that with the same subjects at 1:2 and ~ 35 feet at f/9, f/11, and f/16 my 210/9 Konica Hexanon GRII shot better than my 200/4 MicroNikkor AIS. This on a Nikon, so all I saw was central sharpness and contrast. There was no contest, the GRII is a much better lens.

    In the french LF forum, Henri Gaud wrote "Apo-Saphir Boyer Paris <snip>600 mm F/10 (celui est très bon, je l'utilise encore, a part le cercle de couverture, même niveau qu'un Fuji C, rendu un peu plus chaud)." This one is very good, I still use it, aside from coverage, same level as a Fuji C, rendition a little warmer.

    The thread in which he made this remark is http://www.galerie-photo.info/forum/read.php?f=1&i=67974&t=37579 Note that M. Gaud is an apostle of the most modern lenses possible. He has often written that LF lenses from the '70s and early '80s aren't good enough for critical work.

    In the end it all comes down to budget and discernment. Those with small budgets and no discernment, like me, can be happy using process lenses as taking lenses at distance. Others may not be so happy.

    Cheers,

Similar Threads

  1. Image quality of convertibles
    By Mark_3632 in forum Lenses & Lens Accessories
    Replies: 7
    Last Post: 8-May-2004, 10:39
  2. 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
  3. heat waves and image quality
    By Dick Clark in forum Style & Technique
    Replies: 2
    Last Post: 19-Jan-2000, 23:16
  4. Will lens separation grow or affect image quality.
    By Nous in forum Lenses & Lens Accessories
    Replies: 2
    Last Post: 7-Dec-1999, 18:55
  5. UV filter: does it degrade image quality ?
    By Dell Elzey in forum Lenses & Lens Accessories
    Replies: 4
    Last Post: 25-Nov-1998, 22:23

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
  •