Enlargeing before scanning

The following web page although dealing with astronomy, would tend to

suggest that many of us should take our negatives to the drug store

and get prints, and then scan the prints.

 

http://digilander.libero.it/comolli/resol2.htm

 

What do others think?

 

Neal

That's not what it suggests to me at all. He doesn't ever suggest getting cheap drugstore prints made. Drugstore prints

aren't likely to capture all that's on a tech pan negative,

by a long shot. The paper finish, enlarger lens, and focus will

usually limit resolution to much less than what was originally

on the film. If the drugstore is using a Frontier, then the

prints will be made from scans anyway, and the prints surely won't

be any better than the Frontier scans.

<p>

He does say there's advantage, in certain situations, to optically

enlarging before digitizing. By taking a macrophotograph of your

negative at 3x or 4x onto high resolution film, and then scanning

the enlarged film duplicate, you may be able to pull some detail

out that couldn't be pulled out by a straight scan of the original.

But an optical enlargement onto high resolution film is different

than a cheap drugstore print on fuzzy, thick-emulsioned paper.

<p>

If he had a scanner of high enough resolution to match the tech pan

he's using, he might not see a benefit from optical enlargement.

The optical enlargement just seems to be a way to get around limited

scanner resolution.

Scanning a well made 10x print from a 35mm negative or slide at 600 dpi on a reasonable flatbed scanner gives far better resolution than most filmscanners are capable of. There's practically no loss of useful image detail in a good hand-made colour print, and the final scanned resolution approaches the theoretical 6000ppi. I know, I've actually done the comparisons.<br>However, a scanned print is totally incapable of capturing the shadow detail, dynamic range, and colour accuracy that you can get from a good film scan.<br>The overall edge in quality, therefore, still goes to the filmscanner, but the print and flatbed combo can easily achieve a higher resolution.<p>Even scanning a gloss finish 'drugstore' 4x6 print should give equivalent detail to a reasonable 2400ppi filmscanner.<br>The lenses used in most photofinishing equipment these days are of a very high standard, using field flatteners and incorporating many more optical elements than a standard enlarging or scanner lens. So it's completely wrong to dismiss all minilab prints on the criterion of sharpness alone.<p>Conversely, many drum scanners that purport to output 6000 or more ppi, have comparatively poor focus or lens quality, and they really don't reach an optical resolution of more than about 3000 ppi.<p>The short answer is: Don't knock it until you've tried it!