Page 8 of 13 FirstFirst ... 678910 ... LastLast
Results 71 to 80 of 127

Thread: 210mm for 8x10"

  1. #71

    Join Date
    Nov 2014
    Location
    Eastern Ontario
    Posts
    83

    Re: 210mm for 8x10"

    I haven't seen it mentioned here, but how about the 8.5 " / 215 mm f4.8 Series-S Caltar ?
    Highly recommended, it covers 8X10, and is convertible to 14".

  2. #72

    Join Date
    Oct 2017
    Posts
    409

    Re: 210mm for 8x10"

    I'm wondering if my 210mm g-claron lens is a bitt off. Seems very good on the ground glass and focus is accurate on the film, but the edges are soft, even at f45 without too much movement. This is under an 8x loup. Contact prints of course look fine. What do people reckon? It's a great lens for contact printing, but not really enlarging? Lovely light and small, though!

  3. #73

    Join Date
    Jul 2016
    Posts
    4,566

    Re: 210mm for 8x10"

    At f/45 diffraction limit is 35 lp/mm, so half of the presumably peak peformance of a G-Claron in the center, but around the performance it may have in the corners.

    https://125px.com/docs/manuals/lense...neider/gcn.pdf

    For contact printing you don't need a lens...

    Just print a resolving target http://www.takinami.com/yoshihiko/ph..._test/USAF.pdf and learn how to measure lp/mm, you have to find around 60 lp/mm in the center and around 35 in the corners for a G-Claron at f/16.

    You can use a DSLR mounted in the back for that. You also can use an eyepiece (or 20x microscope ocular...), mount it in a lensboard and place it in the back in the place of the spring-back, you will see it "in the air".

  4. #74

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    8,469

    Re: 210mm for 8x10"

    Quote Originally Posted by Tim V View Post
    I'm wondering if my 210mm g-claron lens is a bitt off. Seems very good on the ground glass and focus is accurate on the film, but the edges are soft, even at f45 without too much movement. This is under an 8x loup. Contact prints of course look fine. What do people reckon? It's a great lens for contact printing, but not really enlarging? Lovely light and small, though!
    And now a polite little flame war of nothing at all begins. Schneider claims that the lens covers 260 mm at infinity @f/22. This claim is based on MTF considerations. They also say it reaches full coverage at f/22, i.e., that stopping down farther won't increase coverage.

    Many users here dispute this vigorously. I vaguely recall claims of as much as 90 degrees, but my memory could well be failing.

  5. #75
    Corran's Avatar
    Join Date
    Apr 2011
    Location
    North GA Mountains
    Posts
    8,924

    Re: 210mm for 8x10"

    Dan - apologies if I've asked this before, but do you know what exactly the MTF considerations were/are from Schneider? The discussion of coverage as it relates to the manufacturer's claims is all well and good, but I don't think it's that relevant for 8x10 and moderate enlargements (much less contact prints).
    Bryan | Blog | YouTube | Instagram | Portfolio
    All comments and thoughtful critique welcome

  6. #76

    Join Date
    Jul 2008
    Posts
    3,901

    Re: 210mm for 8x10"

    Illustration of the lens-optics problem with 8x10. Lenses that properly cover 8x10 is less common, larger cost more and not any where as easy to obtain.

    Schneider data says the 210mm G Claron is good for 4x5, f22, infinity with an image circle of 260mm, too small for 8x10 which is why the corners are "soft".
    https://www.schneideroptics.com/pdfs...aron/chart.htm

    Difficulty here, there is a HUGE difference between designed image circle of optical performance -vs- illumination circle. Will the 210mm G Claron light up the film frame for 8x10 apparently yes, will the 210mm G Claron produce a GOOD and proper image for 8x10 at infinity, NO.

    *Why is there a continued total dis-respect for specifications published by the folks who designed, produce, sold, warranted these optics?
    If Schneider states in published specifications a 210mm G Glaron does NOT cover 8x10, believe it rather than calming it does cover 8x10 then discovering the results are poor then going into denial this cannot be correct?

    What is at the root of this Dissonance?

    Reality is, lenses in the 200mm range for 8x10 is NOT easy, low cost or simple. Again, back in the 8x10 days, the preferred 200mm lens for 8x10 was a 200mm f6.8 Rodenstock Grandagon, BIG, HEAVY, Expensive but worked great.


    Bernice






    Quote Originally Posted by Tim V View Post
    I'm wondering if my 210mm g-claron lens is a bitt off. Seems very good on the ground glass and focus is accurate on the film, but the edges are soft, even at f45 without too much movement. This is under an 8x loup. Contact prints of course look fine. What do people reckon? It's a great lens for contact printing, but not really enlarging? Lovely light and small, though!

  7. #77
    Corran's Avatar
    Join Date
    Apr 2011
    Location
    North GA Mountains
    Posts
    8,924

    Re: 210mm for 8x10"

    One must still be careful, when talking about G-Clarons, to specify which type of lens they are discussing. Results may vary depending. As for small, good, and inexpensive 210mm lenses, the Graphic Kowa and Computar are available, with the GK selling for only about $450-500 last I saw. My GK is excellent, and I have enlarged an 8x10 (digitally) up to 32x40 and it still looked great everywhere. What is the "claimed" coverage for the GK?
    Bryan | Blog | YouTube | Instagram | Portfolio
    All comments and thoughtful critique welcome

  8. #78

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    8,469

    Re: 210mm for 8x10"

    Bryan, IIRC Schneider and R'stock both say that coverage ends where MTF has fallen to 10%.

    Bernice, users' preferences differ. So do their practices. The more important image quality in the corners is, the greater the enlargement, the less a lens covers. Images where IQ in the corners isn't very important can be enlarged more than ones where it matters a lot. And corners that are good enough for contact printing may not allow much enlargement.

    Coverage (subjective, as reported by a user) is whatever the user says it is, but what's good enough for one user may not be good enough for another.

  9. #79
    Corran's Avatar
    Join Date
    Apr 2011
    Location
    North GA Mountains
    Posts
    8,924

    Re: 210mm for 8x10"

    I have read on multiple occasions the supposition that Schneider et al. limit IC specifications to a more rigorous standard for process lenses. Is it possible this was done for the G-Claron line of lenses? I am guessing the actual MTF charts are not available. If so, I think it's a bit of a stretch to blindly follow the stated IC, especially for a lens not sold originally as a general-use camera optic (right?).

    And yes, of course I agree with the rest of your post. I could point (again) to my 305mm G-Claron that covers 8x20 film.
    Bryan | Blog | YouTube | Instagram | Portfolio
    All comments and thoughtful critique welcome

  10. #80
    Drew Wiley
    Join Date
    Sep 2008
    Location
    SF Bay area, CA
    Posts
    18,337

    Re: 210mm for 8x10"

    That's certainly true. G-Clarons realistically cover a much bigger image circle in terms of general photography than the process specifications at f/22. But given the fact we tend to use movements on view cameras, while process applications are point blank, even at smaller apertures, it is probable in some applications that the corners of 210 on 8X10 film would show a bit of sharpness loss. Even with my 240 G, I stop it down to f/64 if strong tilts are involved and I'm contemplating a print 20x24 or larger. Not my favorite lens for 30X40 prints, but I must qualify that according to my past experience with Cibachrome, which is capable of a lot more detail than any inkjet. My 250 Fujinon A, similarly designed but MC, is comparable in this respect. But my 360 A... wow! - now that's a winner for those big prints. The 180 A version has a circle of illumination covering 8x10, but about a third of the way into the corners the resolution conspicuously softens. That gives a pretty good clue what would happen if a G-Claron was available in the same focal length.

Similar Threads

  1. Rodenstock Apo-Gerogon 210mm for 8x10" close-up work?
    By Rui Morais de Sousa in forum Lenses & Lens Accessories
    Replies: 2
    Last Post: 13-Jun-2010, 20:48

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
  •