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  1. #1

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    Uneven tonality in an apparently even scene?

    I have a question or two about the tonality of my prints. When I'm shooting anything with a lot of sky, the sky always appears uneven in its tone, despite the fact that it appears consistent to the eye. Is this just a difference between what my eyes see and what the camera sees? The reason that I ask is that it often appears to lighten when it's next to a darker object/tone. Is this a characteristic of film in general? It doesn't seem to happen in my non-landscape shots. I have attached an example, though it's hard to see exactly what I'm talking about. 35mm Tri-X in DDX. Straight print with no dodging or burning, but cropped to square. http://www.flickr.com/photos/71163977@N00/510294056/ Thanks.

    Jmal

  2. #2

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    Attachment is simply a box with a X in on my screen. This might be only my screen, of cours but I just thought I'd mention it.

    pentaxuser

  3. #3
    fhovie's Avatar
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    Causes could include:
    Your camera lens - what kind of distortion does it create? - ALL lenses distort.
    Bromide Drag - negative reaction to specific development proceedures - often mechanical such as agitation.
    Film sensitivity to non visible spectum (UV- IR)
    My photos are always without all that distracting color ...

  4. #4

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    Looks like shutter issues. Are you shooting at the highest or near highest speed of the camera? Is this a FSU (former soviet union) camera? Looks like shutter drag as it starts out and then again when it stops on the other side.

    My Kiev rangefinder, Zenit SLR and Kiev 88 all do this to one degree or another at the highest shutter speeds on a bald sky.

    The reason you probably don't see it on your non-landscape shots is, you aren't running at top shutter speed due to light constraints.

    Try shooting a brightly lighted wall at your top 3 shutter speeds and see what happens on your next roll.

  5. #5
    Monophoto's Avatar
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    Jmal -

    I presume that you cropped the image lengthwise.

    A development problem would most likely appear as unevenness across the width of the film - which would then show up as uneveness from top to bottom in a landscape image like you have shown us.

    On the other hand, one can expect that there will be a gradation in sky tonality from the horizon up. So I would tend to accept that the top to bottom variation is real.

    What is of greater concern is the gradation from left to right - with obviously increased exposure in the middle of the frame.

    Two questions -

    1. What camera are you using, and which way does the shutter curtain move in that camera? Does it move from left to right (or right to left), or does it move top to bottom?

    2. What lens are you using? Specifically, are you using a wide angle lens?

    This could be a shutter problem, or it could be the natural phenomenon that the center of the field will receive more exposure than the outer perimeter. But we need to know more to determine which it is.
    Louie

  6. #6
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    From what I can see the most likely scenario is the enlargers light source has a fall off at the edges, for a diffusion type, or a mismatch in focal lengths between the condensor and enlarging lens with a condensor type, or the wrong bulb in either type.
    Gary Beasley

  7. #7

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    Camera: Nikon FM2N
    Lens: Nikkor AI 50mm 1.4
    Enlarger: Omega C700 with Nikkor 50mm 2.8 lens and stock bulb

    The shutter was checked in September and was within spec at all shutter speeds. I don't remember the exact shutter speed used in the photo, but I think it was around 1/1000 at f16. Max is 1/4000. The photo was cropped at the top and was not cropped to eliminate a problem; I just likd it square better. The real question in this one is the difference in tonality at the left and right edges. Thanks for the ideas. I'll have to look at a number of prints and see if I find any patterns.

    Jmal

  8. #8

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    Quote Originally Posted by jmal View Post
    I have a question or two about the tonality of my prints. When I'm shooting anything with a lot of sky, the sky always appears uneven in its tone, despite the fact that it appears consistent to the eye. <snip>
    Straight print with no dodging or burning, but cropped to square. http://www.flickr.com/photos/71163977@N00/510294056/ Thanks.

    Jmal
    I know this is a silly question, but are the corners of the paper that lies on the easel laying flat? I have the same problem with my borderless easel where the paper doesn't lie flat. To fix the problem I get double-sided tape and put it in the corners of the easel.

    Another possibility is that your enlarger isn't set for the correct condenser distance. On my Beseler 23CII I can set the condenser anywhere between 35mm and 6x7. If I set it incorrectly then you can get a hotspot in the middle.

    Well, those are my two ideas. Good luck!

  9. #9
    Gary Holliday's Avatar
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    My initial thought when looking at the print was a light leak at the edges of the film. I had a bad batch of cheap Eastern European film which done this.

    My suggestion is to shoot some colour transparency film to eliminate any possible enlarger problems. Photograph sky again or something with a continual tonal range.

  10. #10

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    The easel is a very flat 4-bladed easel, so I don't think that is the problem. It also seems that if there were a light leak on the edges, they would be darker, not lighter. I don't believe my enlarger has any adjustments for the condenser. I am attaching another link for a photo taken at the exact same place and exposure, just framed differently. I did print it a little darker than the other, so I'm not sure it's a fair comparison. This one seems lighter at the horizon and around the tree in particular. The top, which would correspond to the right side of the other image, seems fairly consistent.http://www.flickr.com/photos/71163977@N00/511310878/
    Thanks for the help.

    Edit: the suggestion to shoot some slides seems good. I'll do that after I finish my current roll.

    Jmal
    Last edited by jmal; 05-23-2007 at 05:41 PM. Click to view previous post history.

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