Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: PSA DC-9-30 on November 30, 2007, 02:31:39 am
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I need to scan several hundred pieces of non-standard sized (3x4") BW negatives for a project at work. I just bought, hooked up and started using a new Epson V700, mainly for this purpose. There is no included film holder in this size, but the instructions said that such odd-sized film can be scanned using their flimsy "film area guide". After a bit of tweaking of levels, it worked. (I'm scanning at 3200 ppi, 8-bit grayscale) The images look OK, but, as the instructions warned, there are Newton rings (actually dark bands) running parallel to the long side of the film. Fortunately they are not affecting the cell I'm interested in (yet), but they irritate me nonetheless.
Can anyone explain what causes them, and whether there a way to get rid of them in my scans!?
Thanks
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Newton's Rings are generally irregularly shaped concentric rings that are caused by very slight moisture when the negative touches the glass. So it doesn't sound exactly like Newton's Rings you''re dealing with. You may be dealing with other scanner attributes though. You can try building your own mask cutting an aperture out of black matte board and then taping the neg to the UPPER side effectively suspending the neg 1/16" - 3/32" above the glass. There is plenty of depth of field to keep things in focus. Or... you can wet mount in the same manner film is mounted to drum scanners, but it's actually more difficult on a flatbed than a drum.
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It sounds like you might be having streaks/bands caused by miscalibration. Have you made sure the top 2 inches of the scanner glass bed is absolutely spotless? That can often be enough to clear things up. If you are going to suspend your film off the glass, you will want to get it into the 3 mm range and use the "film with film holder" setting.
Doug
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Thanks for your comments. I have attached a .jpg of one of the scans to show you what I'm talking about. Maybe these are not Newton rings, but the Epson manual refers to Newton Rings as dark bands. These are especially visible on the left, but also appear on the right. I've had to tweak levels considerably with the Epson Scan software (I only installed Silverfast today); without tweaking, 98% of the image is completely blown out. The data box had to be masked and tweaked separately in Photoshop.
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So that's what a computer virus looks like? That, or you're scanning to the cell level, phenomenal resolution.
PSA, are you talking about the distinct, dark line on the right edge and the much wider, darker area that takes up the left 1/4 of the image, both running vertical?
Or, are you talking about the slightly diagonal darker/stripes that are mainly visible in the lighter areas of the image?
If you are referencing the darker, more consistent strips on left and right... those don't look like any kind of artifact that comes from your slide/negative making contact with the glass, anyhow, nothing that I've ever seen.
They look like some kind of shadow...I'm not familiar with the Epson film holders but maybe your problem is coming from that.
It almost looks like you are scanning with no backlight because the label of the slide is casting a shadow onto something there. The darker area on the left looks like a shadow as well. Double check to see if you are scanning in transparency mode.
Those slightly diagonal stripes in the lighter areas? Hard to say..they aren't stepper motor related because they aren't in a horizontal or vertical orientation.
On my old linotype-hell flatbed, there is a small strip of glass at the end of the scanning bed. If that little strip of glass gets covered during a scan, I get strange stuff going on. It's a calibration strip and if your Epson has one, you might look into that. I very much doubt that this is the problem.
Hope that helps.
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Just to add to what Pete said, are you sure you have removed the insert from the lid of the scanner? In regard to calibration area, yes, the Epsons have them and that is why the top two inches (really just one) need to be absolutely spotless. Note the cutout along the top edge of the holder. Nothing must cover it.
Doug
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Yes, I certainly did remove the document mat in the scanner lid--maybe I ought to check whether the lamp is actually working! I'm going to try different locations on the scanner bed within the film area guide when I go back on Monday, but really, anywhere within the Film area guide should work! Utimately, I'm planning on placing four of these on the scanner bed at a time and scanning each individually, so as to minimize opening and closing the lid.
I do have a dust blower, but what should I use to remove any smudges or more stubborn pieces of junk that may appear on the scanner platen? Does this glass have a coating I need to worry about, or would plain old Windex on a soft cloth suffice?
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Definitely NOT Newtonn's Rings. Maybe an aerial shot of Guantanamo. Seriously, it looks like CCD artifacts or banding. Are you doing a lot of correction in the scan software that might be pushing the llimits of the scanner?
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Definitely NOT Newtonn's Rings. Maybe an aerial shot of Guantanamo. Seriously, it looks like CCD artifacts or banding. Are you doing a lot of correction in the scan software that might be pushing the llimits of the scanner?
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Um, could be. When I scan with no correction, 98% of the film is blown out. Looking at the histogram, nearly all of it is to the right of the white point slider, so I slide it to the right so that everything appears normal. When I do this, the problem definitely gets worse. Perhaps there is a better way to correct for this overexposure? As I said, I only installed Silverfast yesterday and have not really tried exploring its features.
For what it's worth, my reflective/document scans look OK. I might try some Kodachrome next week and see how that looks.
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I second the opinion that they're not Newton's rings. Newton's rings result from the film *nearly* touching the glass holder and are usually concentric, or at least curved.
Your artifact is perfectly straight and exactly at right angles to the scan path, right? Have you tried other holders, other films, other media?
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Your artifact is perfectly straight and exactly at right angles to the scan path
Definitely not Newton's Rings (which are rings by he way). Actually the streaks are running in the same direction as the scan right?
Aside from the suggestions to clean the calibration area as mentioned above, I have seen these bad right out of the box. There is a procedure in the Epson website for resetting something that can cause this. It involves unplugging the scanner from power, unplugging the lid, plugging the scanner back in then replugging in the lid etc. Look it up. Its been awhile since I did it on a 4990, but it did solve a similar problem like this that cleaning the calibration area did not solve.
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Thanks everyone. I never really checked to see whether these areas are spotless clean, because it is a brand new scanner--but I guess that is no guarantee. I will call Epson tommorrow and see what I can find out.