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Author Topic: Rediscover – Understanding Resolution  (Read 1003 times)

drralph

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Rediscover – Understanding Resolution
« on: March 03, 2018, 09:02:24 AM »

When reposting Michaels archive, it would be helpful to include the original publication date.  This helps us place the information into historical context.  Enjoyed the article, as always.
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Chris Sanderson

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Re: Rediscover – Understanding Resolution
« Reply #1 on: March 03, 2018, 11:08:28 AM »

That article originally appeared in 2001

More on this topic written around that time by Ron Harris can be found here
« Last Edit: March 03, 2018, 11:13:53 AM by Chris Sanderson »
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Jim Kasson

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Re: Rediscover – Understanding Resolution
« Reply #2 on: March 03, 2018, 12:32:41 PM »

"These printers, such as the models 870/1270/2000P are (somewhat misleadingly) listed as 1440 dpi printers. This means that they are capable of laying down that many dots per inch. But, to create a color image they need to use 6 different inks, so any particular pixel reproduced on a print will be composed of some dithered composite of colored dots using some or all of these inks. That’s why you need more dots from your printer than you have pixels in your image.

If you divide 1440 by 6 you end up with 240. This is the true minimum resolution needed to get a high-quality photo-realistic print from a 1440 dpi Epson printer. Many users, myself included, believe that a 360 ppi output file can produce a somewhat better print. If my original scan is big enough to allow this I’ll do so but I don’t bother ressing up a file to more than 240 ppi when making large prints."

I don't understand why you'd divide the marking engine pitch by the number of inks to get the resolution you need in the file fed to the halftoning software. It seems totally nonsensical.

The Epson halftoning software in the driver has, as far as I know, always resampled the input image to 360 ppi.

Jim

digitaldog

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Re: Rediscover – Understanding Resolution
« Reply #3 on: March 03, 2018, 01:25:50 PM »

The Epson halftoning software in the driver has, as far as I know, always resampled the input image to 360 ppi.
Finest Detail setting?
https://www.digitalphotopro.com/technique/photography-workflow/the-right-resolution/#

In the Epson 4900 print driver, I checked the option for Finest Detail. This makes the print driver report to the pipeline as a 720 dpi device.
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Andrew Rodney
Author “Color Management for Photographers"

Jim Kasson

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Re: Rediscover – Understanding Resolution
« Reply #4 on: March 03, 2018, 02:57:50 PM »

Finest Detail setting?
https://www.digitalphotopro.com/technique/photography-workflow/the-right-resolution/#

In the Epson 4900 print driver, I checked the option for Finest Detail. This makes the print driver report to the pipeline as a 720 dpi device.

You're right, Andrew. I should have said 360 ppm or higher.

Jim

Telecaster

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Re: Rediscover – Understanding Resolution
« Reply #5 on: March 03, 2018, 04:06:52 PM »

To be fair, Michael wrote the article in 2001. Not sure how well the internals of Epson's driver software were understood then…

-Dave-
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Kevin Raber

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Re: Rediscover – Understanding Resolution
« Reply #6 on: March 03, 2018, 04:20:10 PM »

Yes, please remember these are old articles on timeless topics.  Some things will be different but concepts should hold true.
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Kevin Raber
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Jim Kasson

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Re: Rediscover – Understanding Resolution
« Reply #7 on: March 03, 2018, 04:25:30 PM »

Yes, please remember these are old articles on timeless topics.  Some things will be different but concepts should hold true.

Is there something timeless about dividing the marking engine resolution by the number of inks?

If that were true, you'd have to feed a monochrome printer with the other specs of the original article a file at 1440 ppi.

That's not how error diffusion works.

Jim

digitaldog

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Re: Rediscover – Understanding Resolution
« Reply #8 on: March 03, 2018, 04:34:48 PM »

To be fair, Michael wrote the article in 2001. Not sure how well the internals of Epson's driver software were understood then…
One comment (my comment) wasn't directed at whatever Michael wrote. The Epson 1200 had a Finest Detail option FWIW. That printer was introduced the last century. I'd be happy to ping my friends at Epson to find out if that setting did or didn't resample higher than 360DPI.
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Andrew Rodney
Author “Color Management for Photographers"
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