What Happens when You Scan with the Emulsion Side Facing The Wrong Way?

Discussion in 'Digital Darkroom' started by jon_kobeck|1, Apr 10, 2010.

  1. I just started scanning some B&W negatives on a Dimage 5400 I just piced up and after about 3 rolls of film I realized I had the emulsion side facing up when it should have been down. Visually they look fine. Do I need to rescan?
  2. If they look fine then just invert them in photoshop or another program.
  3. So are you scanning the emulsion side or the non emulsion side. I cant remember which is which on the KM 5400.
    That said, typically I get slightly sharper images scanning the emulsion side, but that varies with the scanner.
    Typically it might be 1 pixel softer edge, but may be little or none with the KM.
    My KM5400II was hit and miss with focus, so I always manual focused each frame for the final scan.
    BTW I have been getting interested in maybe looking for another KM5400II.
    How much did you pay for yours ??
  4. If the scanner's lens is having to look through the film backing to get to the emulsion, there's got to be some degradation. That said it might not be that much. Rescan the other way round and compare?
    I'm gessing you're just autofocussing, with the oem software, at center of frame. Is that the case? If so, the following might help. It assumes you're using the OEM software, Minolta Scan Utility, with it's manual focus ability. If you're using Vuescan, it's focus is automated, doesn't apply.
    With the OEM software, I would suggest manual focus, all the time, at a strategic point (not dead center). This point should be somewhere between the high and low points of your film curvature, in an area of light tone. Void of detail is preferable: the focus mechanism does good focussing on just grain. My pref is the manual focus knob on the front.
    The 5400's depth of focus is abysmal, you have to do everything possilbe to achieve reasonable focus, corner-to-corner. Tactics include off-center focus, coupled with doing whatever you can to get the film as flat as possible.
    If you have your film the proper way round, with the emulsion facing the lens (lens on left, light source on right, as you face the front of the scanner), and move the manual focus knob completely counter-clockwise, you will have moved the film and holder to the left, as close as possible to the lens. Now, slowly rotate the knob to the right, and watch the bar graph. As the bars increase, it's indicating improving focus.
    When the bars peak, it is because the focus mechanism has detected the far side, back of film surface. Keep turning the knob clockwise, the bars will falter back slightly, then advance and peak a second time. This is true focus, at the emulsion.
    Now hopefully your film will sit relatively still for the duration of scan. In reality it will flex somewhat. The warm light source will be a factor. For feedback, do your best focus, then just let it sit, and watch what the bars do.
    For feedback on your film's curvature, try running the scanner with Vuescan and doing multiple "manual" autofocus attempts, at various points around the frame. Vuescan will return numbers, between negative and positive one, that indicate where it thinks the focus should be, through it's full travel. You can map these in a sketch, and accordingly get a feel for your film's topography.
  5. BTW, the 5400 is an excellent scanner, especially for traditional, silver emulsion black and white film, where ICE can't be used. It is much better (than the Canon Coolscans) at ignoring scratches and dust, and delivers beautifully rendered grain and highlight detail. I would use the Grain Dissolver, it is an effective hardware level diffusion of the light source.
  6. If you scan with the emulsion side the "wrong way", you get a mirror image - right handed people become left handed, people are looking "the wrong way", writing in backward. Where do you usually see writing - logos on T-shirts, STOP signs, numbers on houses,street signs, etc.
  7. The picture is inverted, I have done that plenty of times.
  8. I've kept zipped as long as I can, can't stand it:
    Of course the image is going to be mirrored if you scan with the film flipped over. This is not rocket science, LOL.
    Mirrored images can be un-mirrored with no ill effects, even in a PS batch, that's a non-issue. The effects of scanning through the emulsion might be an issue, though.

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