Scanning Resolution

[robertrose]

There are several threads related to specific scanners; here I just wanted to suggest that worry about super-high resolutions such as 6400 dpi for 4x5 film is overkill, and will result in many unhappy hours at the computer.

For example, suppose that you are going to print a 16x20 print on the popular Epson 3800 or 3880. You want at the most 360 dpi for the output file. This means a 5760x7200 image for a 360 dpi print. To get that from a 4x5 negative you only need 1440 dpi. Even at that lower resolution you will downsample for web size images, or if the subject matter requires (see http://robertrose.photos/galleries/l...iver-2008.html).

There are many other issues if you are printing, such as whether to use 8-bit or 16-bit files, etc., and I refer you to Eric Chan's excellent website http://people.csail.mit.edu/ericchan/

There is an excellent set of articles about scanners at the LF home page, but in all honesty I have yet to see a single person examine my prints with a magnifying glass. It is subject matter and composition that makes the photo.

[Peter De Smidt]

<snip>
For example, suppose that you are going to print a 16x20 print on the popular Epson 3800 or 3880. You want at the most 360 dpi for the output file. <snip>

What is your evidence for this?

[robertrose]

Fair question. Instructions from Epson; my own judgment when printing on the 3800 to Epson paper; and Eric Chan's website, a Principal Scientist at Adobe:
http://people.csail.mit.edu/ericchan...tml#native_res
"If the 'Finest Detail' driver setting is unchecked, the 3800's native resolution is 360 pixels per inch (ppi). If the 'Finest Detail' driver setting is checked, the 3800's native resolution is 720 ppi. For most photographs, I recommend unchecking (disabling) the 'Finest Detail' driver setting and preparing your final images at 360 ppi."
Chan explains that the 720 setting is for vector-based data including text, graphics, and line art. He speculates that prints will not benefit from higher resolution higher than 360, and that accords with my experience.
I have no doubt that your experience might differ, especially with different papers and inks, and recommend experiments.

[Jim Jones]

Scanning at exactly the right dpi to print the largest print I expect to make seems logical, but scanning at higher resolution and carefully editing that file allows for perhaps future printing at even larger sizes. I agree with Robert that any downsizing and final editing should be done in the computer at the printer's native resolution. It works for me.

[Preston]

Scanning at exactly the right dpi to print the largest print I expect to make seems logical, but scanning at higher resolution and carefully editing that file allows for perhaps future printing at even larger sizes.

Indeed, it does seem logical, and would certainly work well for a person who does not have a computer with the horsepower and/or storage for huge files. Personally, I scan at 1800 ppi (the max for my Microtek 1800f and Vuescan) to produce a 16 bit TIF file. This file is then saved as a PSD 'master file'. All my editing is done on this file. Output files are for printing or the Web.

I agree with Robert that any downsizing and final editing should be done in the computer at the printer's native resolution.

Same here. If I need to make small adjustments to a print file or Web file, I do exactly as Robert and Jim suggest. Works for me, too.

--P

[vinny]

So..........if i want to make a 16x20 I should scan my film at 1440dpi, open the file in photoshop, spend a considerable amount of time removing dust, make any adjustments, then finally print it.
Then when I get an order for a 32x40, I should fire up the drum scanner, remount the film, and do it all over again?
Thanks for the suggestion but, NO THANKS.

[robertrose]

I salute you; I don't have a way to print 32x40 and no one has ordered that big a print from me. Yet.

[Bill Burk]

Don't you work on a managable proxy file, save the actions and original hi-res, then anytime you get an order... downscale copy of original to optimum for target output print and then apply the saved actions to it?

[Lenny Eiger]

Don't you work on a managable proxy file, save the actions and original hi-res, then anytime you get an order... downscale copy of original to optimum for target output print and then apply the saved actions to it?

Nope. I have a computer that can handle what I am doing. I like just doing it right the first time. Nothing takes that long anyway...

I will also add the concept of "archiving" the image using the scanner, doing the scan to as much of the original image as is technologically possible, as in drum scan. Then if something happens to the film you still have the scan.

Lenny

[Peter De Smidt]

I was under the impression that the native resolution of some Epson printers, with "finest detail" checked, is 720 dpi.

See Eric Chan's comments on print quality at: http://people.csail.mit.edu/ericchan...tml#native_res