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  1. #11
    jd callow's Avatar
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    Others here will be able to explain Hyperfocal distance better than I, but here goes...

    It is when the depth of field for a lens at a certain aperture is more or less from near to infinity.


    When you focus on something such as a sign across a street a certain percentage of the foreground and back ground will also have acceptable sharpness. As you stop down those percentages will increase. At some point everything near to infinity will have the same degree of sharpness. Unfortunately, as you stop down the light begins diffract and the image begins to lose overall sharpness. This is why it is recommended to not stop down beyond f32.

    As an example when I use my Mamiya 50mm at f/8 and focus about 15-20 feet out everything from about 5 feet to (maybe) 60 to 80 feet is in focus. The area behind the point of focus is always larger than the area infront. If i stopdown to f/11 I get just about everything from a couple feet to infinity in "focus." This would be the hyperfocal distance for that lens at that aperture.

    There is a great little windows application that can figure depth of field for any lens length, aperture and film size. I used to have it installed, but can't find, nor do I remember its name. Maybe someone out there knows and will post the url.


    Meanwhile, If you are using swings and tilts to change the focal plane you can get more in focus (assuming it is in the plane of focus) with a larger aperture (smaller f number). This allows you to avoid the problems of stopping down too much. THe problem with this a approach is two fold. 1. if you have to adjust the rear standard it will distort the subject. 2. If and when something falls out of the plane of focus it falls out fast and can look very strange. The other problem with this type of focusing is it often requires a lens with a big image circle. There is a strange, unpronounceable name for this type of focusing -- which I have never tried to remember.

    I hope this helps.

  2. #12

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    Program was probably fCalc at http://www.tangentsoft.net/

    The focusing technique for view cameras is Scheimpflug. Harold Merklinger in Focusing the View Camera elaborates & expands on the technique.
    van Huyck Photo
    "Progress is only a direction, and it's often the wrong direction"

  3. #13
    Bruce Osgood's Avatar
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    A "free-for-the-asking" DOF calculator can be found on Paul Van Warlees site:

    http://www.vanwalree.com/index.html

    Go to the optics pages and read down to where he offers a DOF calculator.

  4. #14

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    Only two more suggestions:
    1- make a shot wide open and check if you're really dead on focus;
    2- try to get a copy of "Image clarity - high resolution photography" - by John B. Willians, and you'll find answers to whatever you could imagine to ask.
    Good luck!

  5. #15
    David A. Goldfarb's Avatar
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    I often shoot cityscapes from a high elevation and tilts usually don't help, because you are typically dealing with perpendicular surfaces like tall buildings and the ground. Occasionally I've used a little front swing for that kind of shot, if there are two or three prominent buildings in the foreground in a line at an oblique angle to the horizon or if there is a receeding shoreline. Try setting up the camera square, using only front or rear rise/fall for framing and stopping for adequate DOF. Try at f:16, 22, and 32 and see what's sharpest.

    A heavier tripod and head will often make a real difference. You might consider sandbags on the front standard to dampen and prevent transmission of vibrations from the shutter if you really want to maximize sharpness. Be sure your cable release is slack.

    If you are on a rooftop or balcony, be sure to shield the camera from the wind.

    As the others have said, for objects in the distance, there really is no substitute for a clear day.

    Tech Pan in Technidol isn't a bad idea and is available in 4x5". It has some extended red sensitivity, so it responds well to red and orange filtration to cut through haze.

    Use a compendium shade to restrict the image cirlcle to the minimum necessary to reduce both lens flare and bellows flare and maximize contrast.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  6. #16

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    In my opinion, you got excellent advice earlier in this thread from Donald Miller. Start with a rock solid, well damped tripod and a small lens aperture.

    I have maintained a love/hate relationship with Tech Pan for many years (26 or 27). I have been testing it again, recently. It is a special purpose film. It is very unforgiving in pictorial applications.

    If you use Tech Pan for a nightscape, consider gas hypersensitization (an old astronomical photography trick) and D-19 developer to deal with the long exposures.

    If you are contemplating color film, gas hypersensitized negative color film would likely be a good way to go.

    I second Don Miller's recommendation of Efke 100 film developed in Pyrocat-HD with minimal agitation. Biting Sharp! However, you will still need to deal with reciprocity failure.
    Tom Hoskinson
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    Everything is analog - even digital :D

  7. #17
    jd callow's Avatar
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    if you shoot at night or early morning just prior to sunrise (sorry have I beat that horse bloodless yet?) use tungstun balanced film. T film will handle the reciprocity failure better, manage the soduim vapor lights and give the sky a nice shade of blue.

  8. #18

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    Your description of your desired results may be purely colorful exaggeration, or perhaps indicate that you have unrealistic expectations. 4x5 film and lensses only have so much resolution....

    If you want the most resolution and sharpness possible of a distant cityscape, the first thing I would do, as already suggested, is take the photo on in sunshine after a hard rain. City air tends to be dusty and polluted, and the rain will increase transparency. The sunshine will cast shadows which will reveal details and increase the perception of sharpness. In general, higher contrast will increase the perception of sharpness.

    As already suggested, some filtration will help with haze penetration. You might try several filters -- sometimes red is too much.

    Tech-pan has very high resolution but can be tricky to get good pictorial results with. You might want to try TMax-100.

    Near-optimum f-stop, camera stability and acccurate focusing matter. Is the plane of sharpest focus where you intended it to be? Check whether objects off the intended plane are sharper than objects on the plane.

    Focusing on the hyperfocal distance might in fact be reduce the sharpness of the main subject. The concepts of depth-of-field and hyperfocal distance are based on the concept of acceptable deviations from perfect focus -- circles of confusion instead of perfect points. If you want the maximum resolution possible, your acceptable deviation from perfect sharpness might be much smaller than what is typically accepted. If so, focusing on half of the hyperfocal distance might leave infinity unacceptably blurry to you. My suggestion is to focus on the most important part of the subject and stop down to approx f16 to f22.

    If you don't get as much depth-of-field as you want, you will either have to try tilts and swings (probably won't help much for this subject), or recompose, or decide to accept the lesser depth-of-field or stop down more and accept small amounts of diffraction smearing.

    There are some similar aspects to the enlarging step: near optimum aperture from the lens, sufficiently flat film, aligned enlarger, etc. Knowing whether you have acheived the potential of the system is easier for this stage, because you can compare the prints to the film as viewed with a loupe. If the film has detail that isn't in the print, then the enlarging step needs attention.

  9. #19

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    Tech pan, gigabit, there is only so far you can go in 4x5 before moving up in format. Eight miles is a long way. I just thought of an artist that has performed this kinda sharpness - Clifford Ross - http://www.cliffordross.com but I don't think this information is on his website though. I went to his Blindspot lecture last month and he demonstrated this kind of sharpness, it seems he took off a year to design his own ULF and went to schneider with an optical engineer and hand selected lenses for this camera. Hope this helps!

  10. #20

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    Even with a ULF, diffraction limited optics and super film, you still need to "get lucky." Atmospheric effects can do you in.
    Tom Hoskinson
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    Everything is analog - even digital :D

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