Scanning - inconsistent colors

[PeterAit]

I am using an Epson V750 to scan a friend's scrapbook, half a page at a time (because they are too wide for the scanner) and then stitching the images together. I am sometimes getting inconsistent colors between the two halves of the same page. I simply shift the page on the scanner and scan again, no changes in settings. What could be causing this? Thx.

[Mark D Segal]

Hi Peter,

The only thing I can think of is that if you are scanning the pages while tey remain in the scrap book, there is usually a bit - or more than a bit - of a hump at the spine, so in that direction, the scanner lid may be more open than for the other half away from the spine, such that more extraneous light seeps into the scan of the half by the spine. Corollary: if you can remove the pages from the album and scan them completely flat in both halves that may eliminate the problem, provided my assumption about the cause holds-up. Or make sure the pages and the lid are placed such that extraneous light is no different for both halves.

[Slobodan Blagojevic]

... What could be causing this? Thx.

Auto exposure or other auto adjustments?

[Garnick]

Hi Peter,

The only thing I can think of is that if you are scanning the pages while tey remain in the scrap book, there is usually a bit - or more than a bit - of a hump at the spine, so in that direction, the scanner lid may be more open than for the other half away from the spine, such that more extraneous light seeps into the scan of the half by the spine. Corollary: if you can remove the pages from the album and scan them completely flat in both halves that may eliminate the problem, provided my assumption about the cause holds-up. Or make sure the pages and the lid are placed such that extraneous light is no different for both halves.

Hi Peter,

I agree with all of Marks suggestions, especially as they pertain to the V750 or any of the present day flatbed scanners.  I scan a lot of "oversize" pieces, up to 20x30 occasionally.  I would assume that the only way to accommodate any oversize piece on a modern flatbed is to use another piece of glass on top of the scanner bed, since all scanners now incorporate a 1/4" recessed scanning glass which will cast a shadow on all sides of the scanned image, very annoying.  Also, without a glass foundation on top of the bed the piece can flex to quite an extent, thereby making a final merge almost impossible.  And of course there is also the matter of focus, since when in reflective mode the focus point is at the recessed scanner glass.  I still use my very old but very dependable Epson Expression 1680 for oversize pieces, since its scanner glass is recessed approximately only 1/32", thereby eliminating any and all shadowing at the edges as well as possible focus problems.  Since I have a "small dealer" account for Epson products from Daymen, I sold one of these scanners to a friend many years ago at cost price, on the condition that if he ever has no further use for it I will buy it back, at a reduced price of course.  That is a very valuable scanner in my business and it's a real workhorse as well.  Very well built and dependable.  I also use the V750, but mostly for film scanning and occasionally small pieces that fit on the scanner glass.  You didn't mention which scanning app you are using, but I use Silverfast from Lasersoft Imaging, a very versatile app with regular updates/upgrades.

Hopefully you might find something here of use in your particular situation Peter.

Gary         


 

[Mark D Segal]

Gary, agreed. And I should add I assume Peter knows that the scanner lid can be lifted from the back for thick media so that it need not sit at a slant for holding the media firmly to the glass. Making sure the lid is horizontal (by lifting it from the back) when compressing it against the media could also help to mitigate extraneous light problems.

[AFairley]

Auto exposure or other auto adjustments?

I think Slobodan has nailed it.  If I recall correctly, the Epson scanning software performs auto exposure unless you uncheck that particular box (in the "professional" interface).

[Mark D Segal]

It's of course always worth trying, but I have never set much store in auto-anything with tone and colour adjustments in digital imaging. At best, it has gotten me part way along.