Info requested re Rodenstock chemco Apo-Ronar f/9 480mm

Discussion in 'Large Format Cameras and Accessories' started by zsas, Jul 16, 2011.

  1. zsas

    zsas Member

    Messages:
    1,957
    Joined:
    May 12, 2011
    Location:
    Chicago, IL
    Shooter:
    35mm RF
    Folks -
    I bought this at an antique/junk shop. Lens is in terrible shape (fungus and haze) plus some of the black paint under the first front element has started to flake off onto the glass. (see image). The iris works like a charm and stops from f9 to f260.

    Is this lens pretty much useless or is this a good find? Paid very little for it so I figured I would “rescue it”. It was in a junk shop that had no heat/ac and has probably sat like that for years in the humid and frigid Midwest seasons.

    I am not able to find much info re this Rodenstock chemco Apo-Ronar lens anywhere. Is this some sort of copy production lens? What is Chemco? I believe the focal length (480mm), allows for 1:1 reproductions from what little I could find re this?

    Feel free to enlighten me what I have. I am really a 35mm/MF kind’a photog, but I always tell friends who ‘junk’ if something has lots of glass, is heavy, made in Germany and cheep get it and figure out later if it was a good buy later so I had to pick this up instead of let her sit through more painful days with no love.
    Best!

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
     
  2. DanielStone

    DanielStone Member

    Messages:
    3,107
    Joined:
    Dec 30, 2008
    Location:
    Los Angeles
    Shooter:
    Multi Format
    rodenstock was the manufacturer

    it was probably used for the graphic arts/reproduction(flat work primarily) industry. AKA "plate" making before digital platesetters

    it'll work as a taking lens, and will cover 8x10 wide open, possibly larger when stopped down enough. Its "sweet" spot from what I've read is around F/16-22

    it's multicoated, (see the multiple reflections in your 4th picture)

    -Dan
     
  3. zsas

    zsas Member

    Messages:
    1,957
    Joined:
    May 12, 2011
    Location:
    Chicago, IL
    Shooter:
    35mm RF
    Thanks for the info!
     
  4. domaz

    domaz Member

    Messages:
    560
    Joined:
    Nov 2, 2007
    Location:
    Tacoma, WA
    Shooter:
    Multi Format
    I've never seen one with "chemco" on it. No idea what that means- the font looks a little different as well, perhaps a company had it engraved? Get out some lens cleaning solution and a microfiber cloth and see how clean you can get it.
     
  5. anon12345

    anon12345 Member

    Messages:
    208
    Joined:
    May 25, 2010
    Location:
    Central OK
    Shooter:
    Multi Format
    Last edited by a moderator: Jul 19, 2011
  6. Ian C

    Ian C Member

    Messages:
    722
    Joined:
    Feb 8, 2009
    Shooter:
    Large Format
    This might shed some light on the “chemco” name appended to the Rodenstock process lens. This would have been a customer request that the process lenses used on chemco products also bear the “chemco” brand.

    Similarly, we sometimes see Schneider lenses with the additional “Durst” name added to the barrel.

    http://www.trademarkia.com/free-trademark-search/photomechanical
     
  7. Ian C

    Ian C Member

    Messages:
    722
    Joined:
    Feb 8, 2009
    Shooter:
    Large Format
    With respect to post #5:

    In theory the 480/9 APO Ronar could be used to enlarge 8” x 10” negatives.

    Unfortunately, in most cases the magnification is too low to be practical for this format. The image area of an 8” x 10” film holder is about 195.5mm x 245.5mm.

    In order to make a 8.5” wide projection to cover an 8” x 10” print we need 1.1X magnification.

    That requires about 1925mm from negative to print. The negative-to-lens distance needs to be about 915mm. Much of that would have to be bellows to place the lens at the proper position.

    To make a 20.5” wide projection to make a 20” x 24” print you need 2417mm from negative to print and 660mm from lens to negative for a 2.7X magnification.

    You’ll need a really generous sized enlarger to accomplish this.

    The above numbers are calculated from the Thin Lens Equation and aren’t perfect for a real-world lens, but the error usually isn’t much.
     
  8. anon12345

    anon12345 Member

    Messages:
    208
    Joined:
    May 25, 2010
    Location:
    Central OK
    Shooter:
    Multi Format
    Thanks Ian for this data. All will be seen as I put together this 8x10 horizontal enlarger (DIY). Distances will be no problem in this configuration. As I only gave $5 for the lens, it wont be a big loss should it fail to perform.
     
  9. Ian C

    Ian C Member

    Messages:
    722
    Joined:
    Feb 8, 2009
    Shooter:
    Large Format
    Horizontal projection makes this much more practical so long as you have sufficient bellows. There’s nothing wrong with using a good process lens for enlarging. I’ve use a 305/9 APO Nikkor for 8” x 10” negatives and later acquired a 240/5.6 EL Nikkor. I can’t see any difference in prints from the same negatives.