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  1. #11

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    Frank, this sounds all correct (except for the EL-Lens, which makes me wonder that this works for 4x5). F32 is a lot for a short lens like that, but shouldn't cause diffraction problems for 4x5. Could it be possible that the flowers got simply blurred by wind? The center flowers could have been in your lee.

  2. #12
    fhovie's Avatar
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    On any other day in the Antelope Vally the wind would have killed this shot. This was actually one of the only windless days this year - I was very lucky.

    If it was the polarizing filter causing a distortion, that is unfortunate - This shot really benefited from the filter both in sky and color saturation. If it is the lens, that is unusual and confusing because I thought the Caltar/Grandagon was at the top of the food chain for design and quality with only the Angulon or Nikkor left to consider. That is why the thread. I have not had similar problems with this lens on other occasions. This shot is unique in that it is color and I almost never shoot color and so almost never use a polarizing lens. The most common filter for me is a Red 25 with maybe a split ND filter, Or a Yellow if I feel less dramatic. I had read that the smallest aperature should be no greater than the folcal length over 4. So the 75mm shouldn't go any smaller than F22 and a 210mm lens shouldn't go smaller than f32. When i am faced with needing DOF that cannot be obtained with tilts (tall trees and far away hills) I often challenge this idea and stop down anyway. This was one of those occasions that I didn't want to take a chance and went to F32.
    My photos are always without all that distracting color ...

  3. #13
    RAP
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    First I think it is a lovely image.

    As for how it was done, I think I would have used a 120 mm lens for more coverage on the 4x5 and moved back so to frame the image as it is here, taking note of the groupings of flowers. You would have gotten a more realistic image without the fall off, plus the feel of the flowers being as close with the longer lens. I also might have waited for a lower angel of sun light. Still it is a nice image.

    I personally have a 65mm super angulon I use for just such a purpose. I intentionally move in close so to get that distorted effect and use it creatively. The lens just barely covers the 4x5 at neutral. But I do not get any blurring at the edges or corners even stoped down to f/45.
    Time & tides wait for no one, especially photographers.

  4. #14

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    I think the softness comes from the enlarger lens, probably not closed enough or enlarger misaligment. I have seen this before, the center very sharp and the corners soft. The fact that you dont have light fall off indicates to me that it might not be the taking lens. Although Don has a good point, you might have had enough coverage but ran out of circle of "good" definition.

    Have you checked the negative with a 10x loupe and see if the corners are soft in the original?

  5. #15
    David A. Goldfarb's Avatar
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    "The lower corners are soft where there is the greates distortion caused by the short lens."

    I've seen this effect with very wide lenses that will just cover when movements are used. It looks like an increase in coma at the corners of the frame. I'm not sure whether this is actually coma or just an effect of the normal wideangle distortion (or perhaps coma is this effect). Maybe the optical gurus have an idea about this.

    Scratch my earlier theory. I was thinking this was like a still life, not a landscape.

    If "the softness is in the negative" as you say, then it's not the enlarging lens, although that is a short lens for 4x5".

    Another possibility is a film flatness problem in the camera--either the film popping in the heat or sagging with the camera pointed down, if it was pointed down.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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  6. #16
    Ed Sukach's Avatar
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    It is not properly "coma" ... that is usually an element centering error. The more I consider this image, the more I am convinced that is is the result of a lens stretched past its design criteria for coverage - and beyond the area of distortion correction - mainly as as result of uncorrected "flatness of field". The "pincushion" effect is rather easy to see in the ~ even pattern at the lower left and right corners - it is far more difficult in the "sky" area where there are no natural patterns/ distibutions. "fhovie" says he is going to continue with another, longer, enlarging lens. I'd be interested to see what the results look like.
    Carpe erratum!!

    Ed Sukach, FFP.

  7. #17

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    Yeah, after seeing the picture it seems to me to be lens distortion not from the enlarging lens. It does look like pin cushion so I think fhovie tilted past the correction of the lens.

  8. #18
    Ole
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    There seems to be two effects on that image: The "stretching" of the flowers in the lower corner, due to the tilt bringing the corners of the film outside the area of good definition for the lens. There is also quite a lot of light fall off, some of which could be from the enlarging lens being pushed beyond its capability.

    An aperture of f:32 seems rather large to me for a tilted wide-angle, I think I would have stopped down to at least f:45 to improve the definition in the corners. Diffraction won't be a visible problem until f:128 at least. It's more important to avoid soft corners, in my opinion...

    Next time try tilting the back instead of the front. That way the entire film stays indide the circle of good definition. if using front tilt for this, you should also use front fall to bring the center of the film on the optical axis of the lens. It's amazing how little it can take to tilt the front too much!
    -- Ole Tjugen, Luddite Elitist
    Norway

  9. #19
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    That is all really good feedback. Since I am going to get some distortion anyway, tilting the back seems like a good idea for the next time. I did use front fall on this one and on a 75mm lens, a little movement really does go a long way! I will also try stopping down even more. I really appreciate all the good comments - You are all a great resource of ideas. - Thanks
    My photos are always without all that distracting color ...

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