Whats the focal length of my lens?

Discussion in 'Large Format Cameras and Accessories' started by KPT, Jul 14, 2008.

  1. KPT

    KPT Member

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    Sorry for such a newbie question. My lens states 13.5cm, what would that be in mm? Thanks!!
     
  2. snallan

    snallan Member

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    Hi KPT, welcome to APUG. That is a 135mm lens.
     
  3. Prarry

    Prarry Member

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    There are ten "mm" in a "cm". mm=millimetre (thousandths of a metre), cm=centimetre (hundredths of a metre) so its 135
     
  4. bdial

    bdial Subscriber

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    To convert all you need to do is move the decimal.

    1 CM = 10 MM
    and 25.54 MM = 1 inch
     
  5. KPT

    KPT Member

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    Snallan, thank you for the welcome and the information!
     
  6. KPT

    KPT Member

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    Thank to everyone for your quick responces!! I just bought a 1940 Speed graphic with a Carl Zeiss 13.5 4;5 lens and was confused when i seen the (cm) instead of (mm). this is my first time with a classic large format camera. Thanks again everyone!!!!
     
  7. Frank Szabo

    Frank Szabo Member

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    The nice thing about the metric system is everything is based on multiples or divisions of 10.

    The bad thing is we have very little in the USA that has the proper measuring scales to deal with metrics.
     
  8. Ole

    Ole Moderator Staff Member Moderator

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    A lack of proper measuring scales in the USA is not a problem with the metric system, but with...
     
  9. Steve Smith

    Steve Smith Member

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    Too many fives!

    1" = 25.4mm.



    Steve.
     
  10. Dan Fromm

    Dan Fromm Member

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    Ole, the sad thing is that both systems are taught in our schools.

    Cheers,

    Dan
     
  11. eworkman

    eworkman Member

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    Now could I have the length in Fahrenheit please?
     
  12. Paul.

    Paul. Member

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    Yes, multiply by9 and subtract 32 or possibly divide by9 and add 32 or prehaps miltiply by 32 and subtract 32 divided by 9 or try :confused::confused::confused::confused::confused:
    regards Paul.
     
  13. JBrunner

    JBrunner Moderator Staff Member Moderator

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    That is in fact a 5&1/3 inch lens. (6&1/2 tortellinis)
     
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  15. bowzart

    bowzart Member

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    I have an acquaintance who's employed as a physicist at NASA JPL. I asked him "you guys at NASA use the metric system, right?" Wrong. "It's all inches".

    Why can't we go back to the cubit system... After all, it is biblically sanctioned. If you have forgotten just how long a cubit is, it is easy to figure out. Take the length of an ark, and divide it by 40.
     
  16. JBrunner

    JBrunner Moderator Staff Member Moderator

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    Didn't NASA crash a probe into Mars because of a metric/standard conversion error?
     
  17. raucousimages

    raucousimages Member

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    If you listen to Jason you can use the following.

    3 Tortellinis to a Cheeto
    2 Cheetos to a Strip of Bacon
    And yes he can use it to calculate DOF also.

    NASA had a Hubble problem because everything was english except one contractor used metric.
     
  18. MattKing

    MattKing Subscriber

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    On the metric/non-metric issue:

    Air Canada learned that one of their big jets really can glide for quite a long way (thankfully, Manitoba is quite flat).

    Matt

    P.S. Here is a link:

    http://archives.cbc.ca/on_this_day/07/23/
     
    Last edited by a moderator: Jul 14, 2008
  19. KPT

    KPT Member

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    Matt, After watching the video i no longer feel like a idiot! I guess there are more like me than i thought.
     
  20. RobertP

    RobertP Subscriber

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    Now come on give us Yanks a little credit ...everyone who went to college in the 60's and 70's knows that .021 Kilograms equals a Lid....lol
     
  21. bdial

    bdial Subscriber

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    I guess it's a good thing I'm not in rocket science anymore.
     
  22. Christopher Walrath

    Christopher Walrath Member

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    I'm working on a new measuring system called the 'Groove System'. Here's how it goes.

    The base measurement is a groove. I figure a groove is a little side step in a funky dance and this might work out to about 20 inches. So 1 groove = 20 inches = 508mm. So one mini-groove would equal 15 inches and 381mm. See, the increases are based on a factor of 1.3333. Decrease go by a factor of 0.75. So a macro groove would equal 26 and 11/16" and 661mm and so on. You do the math.

    The groove system. Write it down.
     
  23. Photo Engineer

    Photo Engineer Subscriber

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    I have not followed this thread for "obvious reasons" but three pages to tell a person that MM = CM x 10 is rather excessive and is the reason why other forums are mocking us. I apologize to the OP, that was answered in the first post. He need not worry, as I mean no comment about his OP.

    If you have OT comments we should have some way to handle that. Oh, we do, start a new thread. Sorry.

    PE
     
  24. JBrunner

    JBrunner Moderator Staff Member Moderator

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    Boy, we're having fun now!

    MM= CMx10 was answered in the first post, the rest has been fun. Remember fun?

    Other forums don't mock us. Individuals on other forums might, but why give a rats ass what some crank idiot thinks?

    I do love you, Ron.

    J
     
  25. RobC

    RobC Member

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    MM = Multi Mode on my camera. mm = millimeters. Get it right.:rolleyes:
     
  26. bowzart

    bowzart Member

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    Pedants.

    Conversations evolve.

    How many threads have we seen with page after page after page of useless mind numbing on-topic fluff for every priceless gem of wisdom? That's a problem I have with this otherwise wonderful format; rigidity can sometimes stifle a flow that could otherwise result in new emergent ideas and growth.