Can someone explain hyperfocal focusing on the veiw camera?

Discussion in 'Large Format Cameras and Accessories' started by bmac, Apr 13, 2004.

  1. bmac

    bmac Member

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    I am familiar with the benefits of hyperfocal focusing from my experience with 35mm & medium format gear, and know how to achieve it on those cameras, since the lenses have it all marked out clearly on their barrels.

    Is there a simple way to figure this out on a LF camera? I'd like to figure it out for all my lenses, and mark it on my camera bed for easier focusing in less than optimal situations.

    Can anyone help this dummy out?

    Brian
     
  2. Thomassauerwein

    Thomassauerwein Member

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    Is that when you drink a "Jolt" then go out shooting?
     
  3. bmac

    bmac Member

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    :smile:
     
  4. mark

    mark Member

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    I am so glad you asked. I have been wondering if I was just stupid because I could not figure it out.
     
  5. Thilo Schmid

    Thilo Schmid Member

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    Brian,

    the concept of Hyperfocal Distance does usually not apply to a View Camera. It is substituted by a more general DOF-Concept. However, a View Camera with neither tilt nor swing applied can be regarded as any other "normal" camera and may be focused at a Hyperfocal Distance. But this would be difficult in practice, because there are usually no DOF-scales and/or infinity-stops.

    You may also caluclate the Hyperfocal Distance (in meters):

    H = (f² / ac) / 1000 is a good guess (the exact formula is a bit more complex), where
    f = focal length in mm,
    a = f-stop,
    c = circle of confusion (between 0.075mm and 0.1mm for 4x5", depending on your quality standard)
     
  6. jnanian

    jnanian Advertiser Advertiser

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  7. bmac

    bmac Member

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    Hey John, I tried that site earlier today, the java applet isnt working on my computer (I'm at work), I'll check it from home this evening.

    Brian
     
  8. bmac

    bmac Member

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    Would the COF for 8x10 be 4x that of 4x5?
     
  9. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    Hunt around on the net for a program called f/calc, which computes hyperfocal distances and gives you the formulas and other useful info in the help screens.

    It is true that if you are using tilts and swings to move the focal plane, then hyperfocal distance is less useful, but on the other hand, not every scene is amenable to tilts and swings.
     
  10. jd callow

    jd callow Moderator Staff Member Moderator

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    Don't discount using hyperfocal distance for large format.

    For the most part, I use shorter lenses, which don't have large image circles, and therefore, I don't always have the luxury of movements to change the plane of focus. Truth be told, most situations (i shoot) receive very little benefit from this wonderful capability.

    You should know at what distance and at what f-stop is required to have the desired portion of a scene in acceptable sharpness. The hyperfocal distance allows you to put most everything in acceptable sharpness. If your shooting a meadow that leads to a mountain range than use movements and shoot it at what ever f stop you desire, but if your not so lucky as to have the perfect scene in front of you it is nice to know what to do.
     
  11. MichaelBriggs

    MichaelBriggs Member

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    If one standard on your camera is in a fixed position, you could use the calculators some of the others have referered to to calculate the hyperfocal distance, then use the basic optical equation (1/f = 1/do + 1/di) to convert the hyperfocal distance to a image distance -- lens to film. For accuracy, focus the lens at infinity, then measure how many mm farther out the lens should be to focus on the hyperfocal distance.

    If you have enough time, I find the technique of focusing on the desired near and far points, measuring the spread in position of the standard at the two focus points, resetting the focus to the mid-point and then setting the aperture according to the focus spread works very well. The method is explained at " How to select the f-stop" at http://www.largeformatphotography.info/fstop.html
     
  12. Thilo Schmid

    Thilo Schmid Member

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    Biran,

    standard-COF is format_diagonal / 1500 - at least is this the one that is used to calculate most DOF-scales on lenses. However, this is a rather old convention (dates back to WW II) and film quality is much better today. For larger prints and/or more sharpness use anything between 1000 and 1300. However, an even smaller COF will unnecessarily decrease your DOF.