Scanning DPI

[sanking]

Well, as one of the probably 98% of the population of this board that understands about 2% of the technical discussion herein ... I'd have to agree with Bensyverson ... when I see one of those gapped histograms, I just assume I've completely screwed up my image ... why else would it look like that? ... and that way too much of the original information is now gone and were I to try to print it there would be a huge decrease in detail and tonal values. So, I back up and start over.

This discussion thread has been very enlightening on that and several other valuable points.

You might think of the hole in the histogram in terms of the final print as an early indicator of lung cancer in the human body. Early on there is an irritating cough that indicates something is amiss, but the body is able to continue with its normal activities. Then the hole in the histogram gets larger and larger and eventually the image implodes on itself, and the cough becomes more and more incessant as the cancer grows and the body tries to reject it. Ultimately the result is visual disaster with the print, death to the body.

Sandy King

[Tiziano]

This thread was a great reading. Thanks to All.

[adonis_abril]

What's the results on the prints? I have a Colorgetter drum scanner running on a software than can only scan 8-bit. The upgrade software is almost 1k..and that's for having the capability of 16 bit. The information I've ingested here might just save me the 1k

[Brian Ellis]

You might think of the hole in the histogram in terms of the final print as an early indicator of lung cancer in the human body. Early on there is an irritating cough that indicates something is amiss, but the body is able to continue with its normal activities. Then the hole in the histogram gets larger and larger and eventually the image implodes on itself, and the cough becomes more and more incessant as the cancer grows and the body tries to reject it. Ultimately the result is visual disaster with the print, death to the body.

Sandy King

And I thought darkroom chemicals were risky! : - )

[Brian Ellis]

"I owned a 4990 for a few years and tested it several times with a resolution target. Depending on how optimistically I evaluated the target the effective resolution was between 30-35 lp/mm, or about 1600-1800 ppi".

Your numbers sound just right for my test results. I don't have a target, but I see a modest increase when going from 1200 to 2400 - but nothing after that, except more pixels.

So roughly 4x is around my max enlargement - which for 4x5 and 5x7, is good enough.

I seem to recall the late and sorely missed Ted Harris testing a 4990 and he concluded that 2100 give or take 100 was the maximum it could resolve.

[chacabuco]

So were the prints ever made? I'm curious to hear/see how this all turned out over a year later.