Different Lens Sizes and Focal Lengths on LF Cameras

Discussion in 'Large Format Cameras and Accessories' started by Fragomeni, Aug 14, 2010.

  1. Fragomeni

    Fragomeni Subscriber

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    I have been curious about this for a while I and I was hoping that I could start a conversation about this to find some clear explanations.

    What size lenses can you effectively work with on 4x5 cameras, specifically Speed Graphic and similar brand press cameras. I understand that most 4x5 Speed Graphics came coupled with 135mm lenses and some used 127mm lenses in some cases, the latter being less effective with movements as I understand it but still effective at covering 4x5. What would be the reason for choosing one over the other? Also, I understand that the 3 1/4 x 4 1/4 Speed Graphics usually came with 127mm lenses. Can you use larger 135mm lenses with them to achieve the same end? What differences would you find between the lenses on this camera?

    Further, I have done a lot of reading about cameras modified to accommodate very large lenses and other specialty lenses that otherwise are not explicitly designed to be used with the cameras they are attached to. Some examples include the "Speed Aero" Speed Graphic press camera coupled with Kodak Aero Ektar 7in f2.5 lens, the Aldis Speed Graphic combo which features a Speed Graphic with a Aldis 7in f3.4 lens (both can be seen here), and there are many other hybrids I've read about. What are the explicit purposes of using these lenses on a press camera? What happens with the image that you are making when you use a drastically oversized lens in these circumstances?

    I would love to come to a better understanding of what effects using over and undersized sized lenses, as well as just using lenses of different sizes then come standard on press cameras and other 4x5's will have on photograph making.

    Thanks in advance for your help!
     
  2. paul ewins

    paul ewins Member

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    Francesco, the convenient range of focal lengths on a 4x5 Speed Graphic is 90mm to around 210mm which is wide angle through to portrait lengths. You can go wider or longer with the right lens boards and lenses but they will be more difficult to use. The SG is designed to be used handheld, either with rangefinder or scale focussing or by setting to a hyperfocal distance and using flash to get the optimum aperture for large DoF. It isn't meant to be a field camera which is why the available movements are quite limited.

    The motivation for using the fast aero lenses is usually about minimal depth of field for portraiture. It is a particular "look" that came into vogue a while back that relies on the SG/fast lens combination with the lens used wide open.
     
  3. Wade D

    Wade D Member

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    I agree with what Paul said. My SG came with a 127mm Ektar which is slightly wide for 4x5. I would assume press photographers back then liked it because absolute framing accuracy wasn't needed and they could crop an image. I use mine to it's full potential by composing on the ground glass when the camera is tripod mounted. Otherwise I compose using the top finder and scale focusing when hand held.
     
  4. John Koehrer

    John Koehrer Subscriber

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    If you mean focal length when you say size, then shorter is wider and longer is telephoto(ish). The usual range of lenses was 90-135mm while still using the range finder.
    From the standpoint of using a SG for handheld, journalistic work the 127mm gave a slightly wider field & you could crop more tightly in the printing.
     
  5. Christopher Walrath

    Christopher Walrath Member

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    <Posted via APUG mobile wap service..>

    Kodak also made focal length \'filters\' which are affixed to the Ektar 127 and others. I mention the Ektar 127 as this is what I use on my B&J 4x5. A holder threads onto the front of the lens into which you can place filters which either shorten or lengthen the effective focal length. I have a Telek +2 and +3 which extend the focal length and a Portra -2 and -4 which reduce the effective focal length. I am not sure what those lengths are as I have neither my camera nor my Kodak Reference Handbook readily at hand to provide that information.
     
    Last edited by a moderator: Aug 15, 2010
  6. Fragomeni

    Fragomeni Subscriber

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    I get all of this. I have a 8 1/2 inch (215.9mm) Kodak Commercial Ektar from my field camera that I toss on my SG every once in a while with works like a charm. I've never coupled the rangefinder to this lens however but I've considered it. If I decide to keep the 215.9mm on the SG will I be able to couple the rangefinder (Kalart) to it or will there be some problem with that?

    I understand. Thats what I thought but I just needed that clarification.

    This touches on my earlier question. I have my 215.9mm Kodak Commercial Ektar from my field camera that I occasionally throw on my Speed Graphic. I like using this lens with the SG but I've never coupled the rangefinder to it which I may be interested in doing. Will I be able to couple the longer lens to the rangefinder or is this impossible?
     
  7. Sirius Glass

    Sirius Glass Subscriber

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    It depends on the range finder model and the Speed Graphic model. Side mounted Kalart cannot be adjusted by changing the cam like the top mounted range finders. Top mounted range finders have a nasty habit of "loosing its marble" => the ball bearings fall out. The number of ball bearing is critical, even one to many or one too few is a problem. The right number is model specific. See http://graflex.org/speed-graphic/features.html#KalartSide, http://graflex.org/speed-graphic/features.html#TopRangefinder, and http://graflex.org/speed-graphic/features.html#HugoMeyerRangeFinder

    Steve
     
  8. Graham06

    Graham06 Subscriber

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    Suppose you have a normal lens on a 35mm camera (44mm, f/1.4 say) and you want to take an identical picture with a 4x5 camera (except for the slightly different aspect ratio.) You want the field of view and depth of field to be the same, and you'll stand in the same place.

    You work out the crop factor which is the ratio of each format's diagonals. You divide the focal length of the 35mm lens by the crop factor and you multiply the f-stop by the crop factor. This will give you the lens you need to take the identical picture.

    So you would need a 165mm f/5.3 4x5 lens to take the same picture and an 81mm f/2.6 lens on a 6x6 Rolleiflex. If you had a Speed Graphic with an Aero Ektar attached, your 35mm friends would need a 47mm f/0.7 lens in order to duplicate your photo.

    Here is a conversion table just made:
    [​IMG]
     
  9. Q.G.

    Q.G. Inactive

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    Different formats have different aspect ratios, so different diagonal angles of view even when the horizontal and/or vertical angles of view are the same.
    So i think you have to add two more tables.

    If we assume the lens for 35 mm format to be "1", the factor for 6x6 is 1.57, for 4x5" it is 3.53, if you want the same horizontal angle of view.
    In your notation, that's a crop factor of 0.63 for 6x6 and 0.28 for 4x5".

    If we assume the lens for 35 mm format to be "1", the factor for 6x6 is 2.36, for 4x5" it is 4.24, if you want the same vertical angle of view.
    In your notation, that's a crop factor of 0.42 for 6x6 and 0.24 for 4x5".
     
  10. Fragomeni

    Fragomeni Subscriber

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    Thanks for the help everyone. Much appreciated.