Scanning frustration

[DennyD]

Att'd are images of a 45 yr old photo scanned at 600 & 1200 dpi. The 600 dpi is fair, and a 2400dpi (not here-too large) is excellent, but the 1200dpi is very bad contrast and almost imposible to fix with PE6. Why should the 1200dpi not be a very good image? Several comparative tries yield the same poor job.

I have used 1200 with good results for slide copies. Scanner is a 2007 HP4890, capable up to 4800 dpi, and has been most satisfactory. All scans used the "auto exposure, auto color, and "millions of colors" settings.

[frank abramonte]

DennyD, the 600 dpi looks fine, but could be a little sharper. If the original is sharper than the scan you need better contact of the original to the scanner glass. If not then you can probably add some sharpness with unsharp mask, and/or brightness/contrast. You may also want to try a hue/saturation adjustment to neutralize the colors.
As for the 1200, did you reset the auto settings between scans?

This link on scanning may help you.

http://www.image-access.net/calc/index.html

[DennyD]

Thanks Frank A for the prompt response. The photo here was a bit fuzzy, thus unsharp. Yes I reset the scanner to exact same for each scan.

I've been scanning old B & W pictures, and a bunch of slides, all at 600 dpi. Now I realize this particular photo was the only one I tried at 1200 dpi, with bad results. So I did another from a good quality pic, att'd. The 600 dpi (image 11s) is good (2400 only a bit better), but the 1200 dpi (10s) is unacceptable.

I am beginning to think my scanner is awry at 1200 dpi?!? Need to talk to HP, but it is 2 yrs old.

[frank abramonte]

DennyD, I just did a quick 600 and 1200 scan of the same photo on my scanner, and the results are almost identical. Nothing like your results.
Your scanner must be off on the 1200.
By the way you don't have to scan at 1200 to get good prints, unless you intend to enlarge them considerably. At 600 you should be able to double the size without a problem.