Edge sharpness - RZ67pro2

Discussion in 'Exposure Discussion' started by Alan_Silvester, Apr 10, 2018.

  1. Alan_Silvester

    Alan_Silvester Member

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    Sheffield
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    Hi all,

    I’m having a small issue with sharpness on my shots. The last batch of negs I got developed by the lab (Peak, Sheffield, UK) are showing a slight falloff of sharpness at the edges of the frame, more than I’d expected. I scan at home on a coolscan 9000 and the film is portra 400, shot on mamiya rz67pro2 with no filters. The images in question were shot at dusk, around f16 with an exposure time of about 8-10 seconds (box speed). Exposure is right for the type of shot I’m looking for but the frame shows a falloff of sharpness that’s annoying me.


    I’ve caught focus, they’re sharp across the majority of the frame, so I’m pretty sure it’s not a focussing issue. I’ve scanned on AN glass so the negs are tight and flat across the scanning area. The camera is in mint condition as is the glass, pretty much all mint, or nos stock kit. Mainly shot on 110mm lens, a good sharp lens.


    I’ve always had trouble assessing a neg on a lightbox with a magnifier. Seeing the falloff of the sharpness in this way is tough for me to identify, so I’m not 100% if it’s in the neg or in the scan. I guess that’s a key thing to identify first! I guess I’m asking if anyone has this issue and what ‘best practice’ I can employ to try and get edge to edge sharpness. I much prefer my shots to be sharp throughout the frame, always higher apertures and longer exposures as opposed to anything more ‘arty’.


    The caveat here is that I’m still relatively new to this process and could be making a rookie error but I thought it worth discussing.


    Thanks in advance.
     
  2. ced

    ced Member

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    Belgica
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    Look at the grain across the image if the grain gets unsharp to the edges then I might suspect the scan and not the camera or film.
    Hope you get to the bottom of the issue.
     
  3. MattKing

    MattKing Subscriber

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    See if you can duplicate the problem with shorter exposures of a flat subject in mid-day light.
    If you don't see the same problem with those shots, than the difficulty you are experiencing may arise from relatively extra-ordinary conditions you are working with.
     
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