Your numbera are device dependant. Test we did at RIT had some devices needing up to 600 the lowest 200 dpi. All epson printers raster to 360 dpi regardless of image size so that can fowl up a resolution test since even a 2 dpi file will be rastered to 360 by epson.
From my Android phone on T-Mobile. The first nationwide 4G network.
-------- Original message --------
From: James Schenken <jds@xxxxxxxxxxxxxxx>
Date: 04/30/2013 6:01 PM (GMT-05:00)
To: List for Photo/Imaging Educators - Professionals - Students <photoforum@xxxxxxxxxxxxxxxxxx>
Subject: Re: 5x4 neg scanning
For folks with normal vision, i.e. 20-20, 150 dpi in the final print is about the resolution they can see clearly.
If your vision is better, you can see better.
So the final resolution for a 16x20 print will need to be 600 dpi for the original scan.
That assumes no cropping, no issues with focus in the scanner, etc.
If you want to be safe and account for folks with really good vision, i.e., 20-15 or better, you should scan at 1200 dpi or better. Much higher than that is wasted IF the final target is 16x20.
It is true that drum scanners do get higher resolution. But they also can deliver higher dynamic range than flat bed scanners. Until you get to scan resolutions that can resolve at the grain level, dynamic range counts.
So if you want a working scan that will let you see what's in the negative, a flat bed at 600-1200 dpi is the way to go.
Then you can decide crop, final print size, etc. and whether you need what a hi-res drum scanner can deliver.
James
Luke 23:24
Luke 23:24
Emma flat bed scanners tend to have focus issues which is why the 750 epson is wet mount. And I scan huge files all the time unless you want a 4x5 at 300dpi 360 being ideal for epsons. I print feet some times and even to print a 16x20 from a 4x5 you need 360x4 dpi for optimal and yes I can tell the difference qualityFrom my Android phone on T-Mobile.
