flash wrote:
I have 12MP prints that are 1.5 meters across. They look great. Clients still love them. What I don\'t have is a 36MP version of the same shot to compare it to sitting right next door. I\'ve done the tests and if I put high rest and lower rest together I can tell which is which, even from 12 to 18MP of the same subject. However if I just have a print made then it still looks pretty good at the lower resolution.
It was also noted above that some subjects need more resolution as print size increases and some less so.
Ecarlino..... Bruce Fraser also uses Epson printers. The number 144 is a strange one. An injects actual visual resolution isn\'t the same as the dpi the printer head puts down ink. Simply using 1440 as the absolute resolution of the printer doesn\'t take into account the dithering pattern printers use to mix inks to make their colour palette. All the Epson 1440 printers max out at about 360dpi of usable resolution once this is taken into account. You might see a very slight improvement by working in lots of 180 (180, 360, 720) instead of 144.
Gordon
The specs on the epson 9900 say max resolution is 2880 x 1440.
But are you saying the most it\'s using is 360 x 360 ?
Kinda. Sorta. Not really. Theoretically visual resolution on a 9900 is about 720x360dpi.
Ink printers don\'t really have a \"resolution\" limit. If you take a good quality loupe to an inkjet print you\'ll see that it\'s pretty much continuous tone. The inks blend together to form clumps of information, a bit like film. There\'s a pattern. That\'s the dithering. But essentially modern inkjet printers blend inks really well so you don\'t see \"dots\". Half tone and dot printers have an absolute resolution for the end product (that\'s where 300 dpi comes from - two passes of a 150dpi half tone printer).
Print resolution is in three parts. The capture resolution. The resolution you need for viewing and the best quality information that gets sent to the printer. You can\'t control the first (not at the print stage) but you have some say over the second two. Viewing resolution depends on the subject matter, viewing distance and the eyesight of the viewer. At 1 meter (3.3ft) not many people can resolve better than 180dpi. Some fine art printers use 240 dpi (60 is a common divisor) to ensure they\'re above visual resolution at normal viewing distances.
There\'s absolutely no reason you can\'t have a lower PPI resolution from a file as viewing distances increase or if the subject is low detail or even if you just want to push a print a little bit larger. Once you reach the viewing resolution adding more won\'t reveal more details to the viewer. However if you could put two otherwise identical pictures side by side and one had double the resolution of the other, even though you couldn\'t identify the difference in detail you could tell one is more detailed than the other. That\'s just how the eye works.
So you have a file that is well sized for 240 ppi at normal viewing distances as an image you then go to the third stage, which is to send a file to the printer that is optimised for that printer. With Epson that\'s generally multiples of 180. For Canon it\'s multiples of 300. For Lambda it\'s a 400 ppi file. This works as long as you interpolated up. Don\'t interpolated down unless you\'re really making a small print and you\'re hitting a 600ppi file. You interpolate between part two and part 3. If your printing from Photoshop you\'d use the image size tool or a plug in like GF. You don\'t do this step in LR as it can do it on the fly with a very sophisticated algorithm developed partly by Geoff Schewe..
These three stages also match the three stages of an optimised sharpening workflow. Resize then sharpen for that new size.
Gordon
Oct 28, 2014 at 11:53 PM
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