[SATLUG] OT - photo scanning services

Mark McCoy mark at mccoyfam.net
Sun Jun 1 13:11:50 CDT 2008


Well, I was intending on letting a service take care of the actual
scanning/printing.  I don't have the equipment or time right now to do it
myself.

Thanks for all of the advice and information!

Mark

On Fri, May 30, 2008 at 2:51 PM, Brad Knowles <brad at shub-internet.org>
wrote:

> Mark McCoy wrote:
>
>  Also, these are standard 4x6 prints taken over the last 20 years, what
>> would
>> be a good resolution to scan them as?  I have seen several services online
>> offering 300, 400, and even 600 dpi (for increasing costs), but I wonder
>> which would be the best resolution.
>>
>
> I was going to give you an answer based on my experience of what the
> devices are capable of, but then I did a bit more research and found the
> answer is actually a lot simpler -- if you're scanning from color or B&W
> prints, in most cases you're not going to see any more detail if you scan
> them at more than 300 dpi.  You can probably scan them at 200 dpi and lose
> little or nothing.
>
> If you can get the original negatives, those can be usefully scanned all
> the way down to 3000-4000 dpi, but not the prints.  The problem is that the
> paper just loses way too much of the picture information that is recorded in
> the negative.  There's just no sense in scanning color or B&W prints at much
> above 300 dpi.
>
> See <http://www.scantips.com/basics08.html> for more info on scanning
> prints.  See <http://www.scantips.com/basics12.html> and <
> http://www.scantips.com/basics13.html> for more info on scanning film and
> negatives.
>
> In fact, the whole scantips.com page has got lots of useful info.
>
>
> Color depth and dynamic range are also important.  A $50 cheapie scanner
> might technically be able to do 600 dpi, but will probably have really
> crappy dynamic range, which would make the resulting scans look horrible.  A
> good quality scanner will get you a Drange of 2.5-3.0 or better, depending
> on whether you're scanning color or B&W photos.
>
> Also, don't be fooled by a high Dmax number, if the Dmin number is also
> high -- in those cases, you'd get great shadow detail but all your
> highlights would be blown out.  You want a good Drange (Dmax minus Dmin),
> but ideally you want a Dmin as close to 0.0 as you can get (so it doesn't
> blow out any highlights).
>
>
>
>
> It's also useful to have a scanner with an A/D converter that has more than
> just 8 bits.  Your eye won't be able to perceive the additional bits of
> data, but what this will do for you is make the higher eight bits of the
> data much cleaner, and the fact that the lower bits are noisy is not a
> problem -- especially if you're going to be doing any manipulation in
> Photoshop in a mode that allows more than eight bits per color.
>
> See <http://www.scantips.com/basics14.html>.
>
> I found some other good pages at <
> http://www.kenrockwell.com/tech/scantek.htm>, <
> http://elbereth.obspm.fr/~kervella/Scanners/dmax.htm<http://elbereth.obspm.fr/%7Ekervella/Scanners/dmax.htm>>,
> <http://photo.net/learn/drange/>, <
> http://www.auspiciousdragon.net/photowords/?p=1063> that discuss issues
> regarding dynamic range, Dmax/Dmin, etc....
>
>
> Then there's the issue of color calibration.  It doesn't do any good to
> scan the pictures at the proper resolution if everyone looks like a Green
> Orion Slave, or a Red Denebian Slime Devil because the color calibration is
> way off.
>
> Some of the issues are discussed at <http://www.scantips.com/basics15.html>,
> but see also <
> http://desktoppub.about.com/cs/colorcalibration/a/cal_scanner.htm> and <
> http://www.normankoren.com/makingfineprints1A.html>.
>
> Keep in mind that you need to calibrate the scanner, your monitor, and your
> printer, and you need to periodically go back and re-calibrate them to make
> sure that any color shifts over time are detected and compensated for.  And
> you'll need to have good color management system software on your computer
> to handle all the calibrated profiles that you've got and properly apply
> them.
>
>                                      I do intend to have some of these
>> reprinted eventually (a physical photo album is still nice to have), and I
>> want to ensure that they will still look nice after reprinting.  My
>> scanner
>> is OK, but I don't want to sit for a week scanning pictures unless I have
>> to  :) , only to find out that I didn't scan them at a high enough
>> resolution.
>>
>
> Get them scanned at 300 dpi on a good quality scanner that has a good
> Drange and a Dmin as close to 0.0 as you can get, and fully color
> calibrated, and that will be about the best you can reasonably expect to
> get.
>
> --
> Brad Knowles <brad at shub-internet.org>
> LinkedIn Profile: <http://tinyurl.com/y8kpxu>
> --
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-- 
Mark McCoy
- US Army Veteran
- Professional Unix Geek

Here in America we are descended in blood and in spirit from revolutionists
and rebels - men and women who dared to dissent from accepted doctrine. As
their heirs, may we never confuse honest dissent with disloyal subversion.
-- Dwight D. Eisenhower


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