I am new to collecting coins, I need some help scanning them

Sportycard

Hi,

I was wondering if someone could give some tips on scanning coins. I am using a flatbed scanner at 42 bit color. I am not getting the true color of the coin instead of it coming out silver it looks more bronze.

Any help would be appreciated.


Thanks,

Chris

PS please see scan

This scan is at 200 DPI

dakra

My scanner (Hp ScanJet 3300C) Usually defaults to 150DPI, Black and White for some reason. After scanning, I change the Resolution to 300 DPI, Output Type: Best Color Photograph and then rescan. (It actually has an option to Rescan at Higher Resolution) Once it is scanned, I save it as a JPG, when compression comes up, I generally set it to around 75%.

Hope this helps.

-David

CarlWohlforth

That seems decent. You can try some experiments. Say like try at 72 DPI.

One thing I tried was putting some colored paper next to the coin, then crop it out of the image. That might help the scanner balance colors better. I keep red, yellow and blue paper nearby for that purpose.

Draco

First of all, don't scan at such a low resolution. This probably won't help your color issue, but will help with image detail. Scan the coin at 300dpi or more and use an application like photoshop to resize and change the image resolution.

For the color issue (if it's a new scanner), there should be a setting for automatic brightness/contrast and color. Make sure those are checked. If they are and you still can't get correct color, try doing a three pass scan to see if it improves. If it does not, you'll have to do single channel scans to detect what color is not being properly detected and for best results, try to find something or print something that is pure red, blue and green on separate paper. Variations in shade can indicate a bad tube. (or bad CCD)

You'll have to check your scanner's manual, but there should also be some type of spectrum curve adjustment that will balance out or allow you to change the sensitivity for each of the three colors it can detect. It takes a lot of practice and patience, but you can force the scanner to accept certain levels.

The last bit of advice I can give you is to make sure that the scanner is empty and the lid is closed when you power it up. Some scanners compensate for tube life related issues by doing a mini-calibration when you power it up. You'll notice this because the head will move slightly into the scanning window and each tube will come on individually (this is also part of the scanners self test diagnostics).

Sorry I can't help you more.

Sportycard

thanks for the great pointers I will try all of them

cladking

Welcome to coin collecting. I hope you get much pleasure from it.