Image Capture images from scanner appear dark: Calibration?

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Level 1

20 points

Image Capture images from scanner appear dark: Calibration?

Hi,

I have an Epson Perfection 3490 scanner that I've been using for a long time with my Mac. I don't know if this has happened gradually or it's just started to happen with Mountain Lion, but when I scan B&W or color images "white" appears light gray. Say I scan a text document in Image Capture. If I switch back and forth between "Text" and "Black & White", the background is significantly darker in B&W mode. This is even the case if I scan the white background of the scanner itself with no paper on the glass.

Is there some way I can calibrate the scanner?

Is there something about Mountain Lion's version of Image Capture that might be darkening images?

I've tried googling for "epson scanner white calibration" and such, but I've not found anything. I assume that if I finally manage to find something, I'm likely to find Windows-only software.

If anyone can give me some suggestions on this, I'd really appreciate it.

Thanks!

Posted on Jul 31, 2012 2:14 PM

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Answer 1

theosib Author

Level 1

20 points

Jul 31, 2012 2:19 PM in response to theosib

A little googling around suggests that to a certain extent, the scanner will capture a wider dynamic range than what is necessary for software, and then the image software can do white calibration adjustments. So how can I do this in Mac OS?

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Answer 2

PAHU

Level 6

16,705 points

Jul 31, 2012 3:02 PM in response to theosib

I do think that Image Capture on Mtn Lion scans darker compared with previous versions of the app. I found that I needed to set the Image Correction setting to Manual and then adjust the brightness and contrast to get the desired result.

As for the calibration, most consumer scanners will do their own calibration, using a white strip or backboard on power up, and provide no user interface. If the scanner is a flatbed and uses the white backboard, then having a document on the glass can influence the calibration so ensre that nothing is on the glass when you turn the scanner on.

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