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Scanning and pixels dont equal print quality.


rob_x2004

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Scanning a neg at 2700dpi at 16bit gives me a 60.4MB file. At 300dpi output a canvas dimension or 3960x2664pixels. I can scan at 5400dpi resulting in a 242MB file 7920wide. For editing this is obviously a tough ask of the software.

 

For small home prints, say up to A4 by the time the printer algorithm has had its say in the resampling process I can get a decently edited 240kB file to print as clean as a 10-12MB file.

 

For web presenting I will repair, resample and then edit the final upload dimension image.

 

For home inkjet printing, at what point do you give up looking for more detail in your scan and why?

 

If you use uprezzing software that doesnt just get rewritten by your printer, then at what size do you edit?

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Not me! --- I scan 2200dpi@16bit640*mbfile - then I backpurge @3960x3456 #file A$ MB

242MGfileoutput3906x2665pixelswith10-12#MBfileA4260mb&7920pixel126 uprez @upload= A45 +5 algorithm %$@#&%$ - then frontflush-3000x5000 resample 5400dpi+ edited 240Kb and a couple 12MB@ 32bit and #@60 +uprez it a%! --- It works perfect!!!

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Well, I can, and which is why I said by the time the printer algorithm has its way with the file etc.

I figure that as soon as the print program adjusts large file even by a pixel dimension to fit to page, even in just converting into print then you will have, within limits, the same print quality.

I dont for a minute think that the 240MB files I get from a 35mm neg would hold up to a DMR file either, nor an M8 file in terms of definition. Theres a diminishing returns coming into play somewhere along the line.

Hence my question with respect to file size against editability to produce prints, is there a logic or a calculation behind it or is it just suck it and see, and whether uprezzing smaller scanned files which have been more easily edited becomes a useul printing solution.

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1. Inkjet printers really print at about 240-250 ppi. Send more data than that and it just gets tossed away. Think of 240 ppi as a "AA filter" - doesn't matter how sharp your lens or your file is, it will get dumbed down to that level.

 

2. Sharpening will also get tossed away if it is at a level below the printer resolution. I.E. sharpening at a .5 pixel radius on a 300 ppi file means the sharpening radius is 1/600th of an inch - invisible to the printer. The more ppi your file has, the HEAVIER the sharpening needs to be for a given print size to actually make the detail stand out. Which is why a 240K file can look good - the pixel edges are crisper.

 

Print at 180 ppi, 0.3-pixel USM is good, print at 240-260 ppi, 0.5 pixel USM is good, print at 300+ppi and you need 1.0-pixel sharpening or more.

 

I don't bother with inkjet prints smaller than 10 x 15 inches any more, except as giveaways. I keep buying bigger and bigger paper because it's the only way to get all the detail from an M8 to show up (up to 17" x 22" now). A 14 x 20-inch print at 180 ppi looks much better and has more visible detail than an 8 x 12 at 300 or 360 ppi.

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So what about scanning for the size of print (say 12 x 8) at 240 or 300 dpi - what loss of quality occurs in the resulting print?

 

Is there really any advantage in creating such large files by scanning at such high resolution?

 

Osscat

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Not me! --- I scan 2200dpi@16bit640*mbfile - then I backpurge @3960x3456 #file A$ MB

242MGfileoutput3906x2665pixelswith10-12#MBfileA4260mb&7920pixel126 uprez @upload= A45 +5 algorithm %$@#&%$ - then frontflush-3000x5000 resample 5400dpi+ edited 240Kb and a couple 12MB@ 32bit and #@60 +uprez it a%! --- It works perfect!!!

 

I'm sorry but just what does all that say and mean?

Have you ever heard of the SPACE BAR, the ENTER KEY and the peiod (DOT) key

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Not me! --- I scan 2200dpi@16bit640*mbfile - then I backpurge @3960x3456 #file A$ MB

242MGfileoutput3906x2665pixelswith10-12#MBfileA4260mb&7920pixel126 uprez @upload= A45 +5 algorithm %$@#&%$ - then frontflush-3000x5000 resample 5400dpi+ edited 240Kb and a couple 12MB@ 32bit and #@60 +uprez it a%! --- It works perfect!!!

 

 

 

Thats right! It works perfect!

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Whoa, guys

Scan in ppi and print in dpi, not the other way round!

John

 

Well, not exactly - although if you were referring to Chili's rant, that's understandable.

 

Scan in ppi (pixels per inch) - correct

Print in ppi (pixels per inch at final image size)

 

dpi is what the printer or printing plate does natively - i.e the hardwired number of ink drops or plate dots per inch - regardless of the size or resolution of the source image itself.

 

I.E. my Epson prints at 1440 or 2880 DOTS (dpi) per inch, depending on which I choose, with no regard for the image resolution or size. That is fixed by the spacing of the ink outlets and how often it spurts in crossing the paper.

 

If I print a 6 Mpixel (2000 x 3000) image 10" by 15", I am printing at 200 PIXELS per inch (2000 pixels divided by 10 inches/3000 pixels divided by 15 inches) = ppi

 

If I print the same image 6.66" x 10", then I'm printing at 300 PIXELS per inch.

 

In either case the printer is still using 1440 or 2880 dots per inch. Or 85, 150, 300 dots per inch if it is a screened printing press rather than inkjet.

 

I'm starting my 24th year as a publication designer, so I know a little about the subject. If I need to determine whether an image will reproduce cleanly on our press (newsprint/75 dpi), the key number I look at is pixel resolution - how big can it run and still contain at least 200 PIXELS per inch at final print size.

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Well, not exactly - although if you were referring to Chili's rant, that's understandable.

 

Scan in ppi (pixels per inch) - correct

Print in ppi (pixels per inch at final image size)

 

dpi is what the printer or printing plate does natively - i.e the hardwired number of ink drops or plate dots per inch - regardless of the size or resolution of the source image itself.

 

I.E. my Epson prints at 1440 or 2880 DOTS (dpi) per inch, depending on which I choose, with no regard for the image resolution or size. That is fixed by the spacing of the ink outlets and how often it spurts in crossing the paper.

 

If I print a 6 Mpixel (2000 x 3000) image 10" by 15", I am printing at 200 PIXELS per inch (2000 pixels divided by 10 inches/3000 pixels divided by 15 inches) = ppi

 

If I print the same image 6.66" x 10", then I'm printing at 300 PIXELS per inch.

 

In either case the printer is still using 1440 or 2880 dots per inch. Or 85, 150, 300 dots per inch if it is a screened printing press rather than inkjet.

 

I'm starting my 24th year as a publication designer, so I know a little about the subject. If I need to determine whether an image will reproduce cleanly on our press (newsprint/75 dpi), the key number I look at is pixel resolution - how big can it run and still contain at least 200 PIXELS per inch at final print size.

 

 

Very clearly explained with one nuance. Your Epson's native resolution is 720 dpi which the printer driver is using to drive the print head at either 1440 or 2880 (multiplying the 720 dpi information to the desired 1440 or 2880 dpi output). If you want to get the printer driver as far out of image interpolation as possible (a good idea as the Epson drivers aren't the best image interpolators) - then send the printer 720 dpi (the best way) - or an even division of 720 (360, 240, etc.).

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In either case the printer is still using 1440 or 2880 dots per inch. Or 85, 150, 300 dots per inch if it is a screened printing press rather than inkjet.

 

I'm starting my 24th year as a publication designer, so I know a little about the subject. If I need to determine whether an image will reproduce cleanly on our press (newsprint/75 dpi), the key number I look at is pixel resolution - how big can it run and still contain at least 200 PIXELS per inch at final print size.

 

adan,

 

Is not the best quality print a factor of 1440 (or 2880)??

Say, 180 or 360?

 

Just asking.

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