image circle size

Discussion in 'Large Format' started by ken_schroeder, Feb 5, 2003.

  1. One of the most important specs for large format lenses seems to be
    the image circle size. The coverage at f22 seems to be a prime
    benchmark for choosing between lenses. Over the years my lenses have
    grown smaller, lighter and have smaller coverage. I started out with
    a 210 Symmar S, which has served me very well. Several years ago I
    added a 200M Nikor. The Symmar covers almost 300mm at f22. The
    Nikon, a Tessar design, covers only 210mm. I have not found that to
    be a constraint in my field work. My shorter lens, a 135 Nikon W,
    covers about 200mm, which has not been a problem, either. My
    tightest lens is the 105 Fujinon W, which at 162mm barely covers a
    4x5 negative. I rarely use that wide of a lens, but on the few
    occasions when I have used it the coverage has seemed adequate.

    I would like to hear some other people's thoughts and experiences in
    this area.
     
  2. One of the reasons I moved up to 4x5 was the separation of the film plane from the lens. I wanted to make things "look right" in a way I can't with 35mm. Note that I do primarily landscape work.

    I often, in the field, level and plumb the film plane. To then get my framing right, I use some movements. Sometimes a lot of movements. But my trees don't all converge to a point - which is part of the reason I use a view camera.

    Which lenses do I use? 95% of what I do, I do with a 110mm SS-XL, and a 240mm Fujinon-A. Big honking image circles, these two.

    Does this mean that you are doing something wrong? Hardly. It just means that we have different ways of working and have different priorities. If what you are doing works for you, then by all means remember the thought: "if it ain't broke, don't fix it!"
     
  3. I've bought and own some lenses that are tight on the format and it seems like even in landscape work the rule of thirds will bite you. The darn thing will cover OK but only with the horizon line going right through the center. B O R I N G! If you move over to architectural shots it just gets worse. I confess to liking an ample circle to work in. Since I'm not a millionaire I've sacrificed maximum aperture to get the bigger circle in many cases.
     
  4. The mfg. figures are somewhat conservative. I bought a 135mm nikkor because a workshop presenter showed me negaatives that he had printed to 20x24 inches and beyond, full frame on a 5x7. So the nikon figures are a bit misleading. i suppose estimating les coverage is better than stating emphatically that the lens will cover more. I had similar experiences with the 210 you mention and with my current 210 nikkor.
    On the other hand, a WA schneider I once owned failed me miserably in the field. But then I was using a massive amiount of indirect placement plus rise. I tried to make the lens work when I needed a lens with signifcantly greater coverage. Later I reshot the same scene with such a lens. Piece of cake!
    Some shooting experience develops the analysis you have created.

    Bob
     
  5. I'm lazy (in some respects).

    I shoot 4x5, mainly landscape, but sometimes old buildings. I photograph trees a lot and other vertical objects that involve a fair bit of rise. I don't like to have to worry about the possibility of vignetting and one of my criteria for purchasing a lens is a good coverage.

    Specifically, I currently own:

    Rodenstock APO Sironar S 210 (316mm circle)
    Rodenstock APO Sironar S 150 (231mm circle)
    Nikkor SW 90 (235mm circle)

    I'm planning on getting rid of the 90 and getting

    Schnieder Super Symmar 110XL (288mm circle)
    Schneider Super Symmar 80XL (212mm circle)

    As you can see they're all reasonably generous.

    Mike
     
  6. Thanks, Hogarth, Jim and Bob for your interesting replies. Hogarth, good point about the trees. All too often buildings get top billing and trees are forgotten. Jay Dusard once told me he liked to keep his camera "plumb with the universe." I've tried to do that ever since (excepting the very occasional scene where I want to change the geometry-rare).

    Using the view camera has spoiled me for any other kind of camera. I like being able to find the camera position which best expresses how I see an image, and then being able to use rise/fall and or shift to preserve the geometry I see. I like to make images, indirect portraits for lack of a better term, of small areas with objects which tell something about a person. Work areas, part of a kitchen counter or part of a studio. (Wright Morris' work does this extremely well). I probably use the falling front more than the rising front.

    Yes, the 240 has a "big honking image circle". However, it is not a big honking lens. Occasionally I find the 200 just a bit to wide. I have thought of adding a 240. The diminutive Fuji with the sharp big coverage seems the ideal choice. I don't plan on buying one tomorrow, but your thoughts will remain in my mind.

    Jim, is it legal to photograph the horizon? Just kidding, but I agree with you about usually not placing the horizon dead center. I think of the 105 Fujinon as a wider lens than the 135, and use it when the scene won't fit with the 135. I generally like to compose right to the very difficult to print corners. Mentally, I give myself permission to crop a little with the 105 if the lens doesn't quite cover. I know that's somewhat sloppy. If I used the wide lens more I would bring the 90 SA. I have found on a week's trip, I generally use the 105 maybe once or twice. The 200 and 135 do most of the work....and the 105 is so small it takes hardly any room in the bag. It would also serve as a backup for the 135 should the copal shutter fail. That happened only once back in 1985, but it is nice to have a backup. When the sky is included in my images, which is not very often, I generally tend to place the horizon high. I enjoy seeing other people's work with lots of sky, but for my images I am usually more interested in what is beneath the sky. This is just a personal preference, certainly not a value judgement.

    By the way, I totally agree with you about choosing larger coverage over a larger aperture due to both cost and the difficulty of finding good porters.

    Bob, nice practical observation. I don't get much into technical specs, but I have never run out of room with the 135 Nikon. I like being able to carry it or either the 200 or 105 inverted in my closed camera. I recall making a photograph of some of the roof details of the Meux House in Fresno. I wanted all the front rise my camera could give, including all the front tilt in parallel both axes could give me. It is nice to have tht reserve for the odd occasion when I need it. The 200M would have failed me on that shot. I only had the 210 back then, and was very glad for it.

    Again, thank you for your thoughts.
     
  7. I have found that most of my Nikkor lens have very conservative
    lens coverage specifications. For example I have the Nikkor T
    lens with the 360mm, 500mm, and 720mm rear elements. All
    three of these configurations have a 210mm image circle at f22.
    Yet, I can use these lenses with my 4x10 camera which has a
    diagonal of 270mm. That is almost 2.5 inches greater than the
    lens can cover.

    Upon closer examination I took some density readings of some
    of my 4x10 negative and found that if you exceed 210mm then
    the negatives will start to thin out by as much as one stop due to
    light fall off. I have notice this also on other Nikkor lens I use
    with my 4x10. Thus, I believe that Nikons specifications are
    intended to state the largest image circle without any reduction in
    light,

    Please note, the one stop fall off in the corners of my 4x10
    negative are not significantly noticeable in the final print, If you
    choose you can burn the fall off areas, but I kind of like that effect
    in the skies.
     
  8. I think the light fall-off you experience with the telephotos is caused by the iris placement in a telephoto design lens. The iris is usually placed at the nodal point of a lens, where it operates best. In a telephoto the nodal point is somewhere in front of the lens, so it must of necessity be placed much farther to the rear. My 1200EDT will cover my 12x20 wide open but when you stop it down past f:32 it starts to vignette the corners
     
  9. Stephen,

    By my calculations, a 210mm lens on 4x10 format will have a 1/2 stop fall off at the corners of the film. This is due to the fact that the light is diverging from the lens nodal point and spreading out further at the corners than on the central axis. (It has longer to travel.)

    This calculation assumes no mechanical vignetting and I'm not sure that I understand the effect of the telephoto iris placement issue discussed above. Maybe that makes it more. I don't think it can make it less. You may be getting some mechanical vignetting too depending upon the aperture you use.

    Point is, I think you will always get some fall of at the corners of an image. The effect is most pronounced with wide-angle lenses for your format. The only solution for this that I know of is to use a center filter and avoid mechanical vignetting due to large apertures and lens shades.
     
  10. I haven't noticed a corner fall off problem with my lenses. I do recall some vignetting a time or two over the years, but not often enough to be a problem. It seems the more my camera resembles a pretzel, the less chance the negative will be a keeper. The roof detail shot in Fresno required no tilt, just lots of rise. I am more apt to use tilt with fall, which actually centers the image.

    My corner fall off problem is the cold light on my Beseler. The very corners can be a devil to burn in. The solution is to refrain from using the limits of the negative, but I prefer to compose to the edges. I guess I make my own problems....

    Mike, I am curious as to why you are selling you 90mm. My 90 Super Angulon, which is quite similar has always performed well. I don't use it much, but that is for reasons of composition, not optical quality. The 80 and 110 lengths so seem to be versatile.
     

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