I recently read that printing an image with a resolution that is too high (ie 300+) actually decreases the print quality.
The 10D shooting in RAW format makes a 4x6 that are 512 resolution by default. Am I therefore actually hurting the quality of my prints? Does this apply only for inkjets or for dye subs as well? What about photo lab prints? Is this even true
I recently read that printing an image with a resolution that is too high (ie 300+) actually decreases the print quality.
The 10D shooting in RAW format makes a 4x6 that are 512 resolution by default. Am I therefore actually hurting the quality of my prints? Does this apply only for inkjets or for dye subs as well? What about photo lab prints? Is this even true
Any help on the subject would be appreciated.
Where did you read this?
I haven't experienced this at all... And canon is marketing printers that print directly from camera or CF card. So, I'm guessing the quality wouldn't degrade by any noticable amount. Canon isn't going to shoot themselves in the foot.
For photographs you should be printing at 240-300 dpi.
The higher the number the larger the file for any given print size and the slower the printing. With large prints and really high resolution you risk computer crashes if you don't have lots of RAM and CPU power. The subject matter will determine how low a dpi setting is acceptable.
To my knowledge the printer driver interpolates the appropriate print resolution, based on your "quality"/paper setting. I've never bothered with setting specific resolutions for prints from 4X6 up to A3+, and all come out perfect. In most cases I find the less I fiddle with it better it comes out. Image good, print good.
The printer interpolates for you when then is an abundance of information, same as downsizing a photo.
I print at 200 down to 150 (if I can't help it ) with no visual effects.
I have also heard that too much info hurts print quality. I now prepare all photos to the size I want with the resolution I want. Usually 200 DPI, more is wasted and less "might" degrade the image.
I have never experienced the problem of too high of resolution myself, just found it prudent to avoid it altogether.
if you have a 400 dpi image and the printer prints it at 300 dpi it had to throw away 100 dpi of information (interpolating down) sometimes the software algorithum that does this is poorly writen.. better off doing it yourslef in photoshop using a method you can control.
In Photoshop's image size menu set the resolution to between 240 and 360. Below 240 you will lose quality and above 360 is useless. While many pros argue that 300 is enough, others say that 360 is better because mathematically it is better to have the dpi be a number that can be divided evenly into the resolution of the printer. So with Epson printers 360 can be divided into 1440 or 2880. I guess if you have a printer with 1200 or 2400 dpi then setting the print to 300 would be fine.
Rather than repeat other people's generalizations or fuss with theory, I actually did some experimentation using my Epson 2200. I printed a piece of a photo at 180 dpi, 240 dpi, 360 dpi, and the resolution of the original photo (which was about 215 dpi). The up-ressing and down-ressing from the original was done in Photoshop. When I examined the results extremely closely, the original-resolution one was the worst by very slightly, next worst was 180 dpi, and 240 & 360 were indistinguishable from each other and only very slightly better. In all cases, though, the differences were barely distinguishable, and only because I was looking closely for the differences; a casual viewer would never know the difference. From this, I infer that the printer is resizing, and its resizing algorithm is slightly worse than Photoshop's, but the effect is small enough to not be worth fussing over.
Let's first get the jargon down correctly: Your printer prints in DPI but your image is resolved in PPI. Now, you take your say 300 PPI image from PS or whatever and print it on your printer at 1440 DPI -- thus THE PRINTER IS ABLE TO USE ABOUT 230 "DOTS" TO REPLICATE EACH PIXEL FROM THE ORIGINAL IMAGE. Since each "DOT" can only be one of 6 or 7 colors, how these dots get mixed will create the pixel and explains why the printer needs a good number of them to do it. If you don't have enough DOTS to replicate the PIXEL, then you won't get accurate colors or tonality. Hence if the PIXEL density is TOO HIGH the printer will not be able to accurately replicate them in output. Now understand that most print drivers will downrez overly high pixel density images to 360 or 400 pixels MAX before they print them so that they have a LOW enough pixel density to ACCURATELY reproduce with the printer's DOTs. Hence if you send a 600 PPI image to your printer, the driver will toss out a third or so of them to cover for user ignorance on how to print -- thus insuring a print with reasonable color and tonality can be delivered from their printer.
Jack, nice explaination of the printing details. This entire business of pixels and dots is never intuitive, but it is very important and can definately make the difference as to whether people are happy with their images or not.
It might be helpful if photographers begin thinking that when a "camera pixel" is printed it is made up of "many ink dots" that vary in size and color. Hence the relationship between pixels and dots is not 1-to-1.
You're confusing dpi - (dots per inch, which is printer driven and affects the quality of output), with ppi - (pixels per inch, which is image driven and affects the quality of the image).
ejmatl wrote:
You're confusing dpi - (dots per inch, which is printer driven and affects the quality of output), with ppi - (pixels per inch, which is image driven and affects the quality of the image).
eileen in bc
Eileen: No offense, but Art and I have them right and have explained it in a reasonably accurate fashion. A printer needs several of its available dots to replicate a single pixel from an image accurately.
The last issue of Digital Photo Pro (new mag) had a short article on file resolution/printer resolution relationship for ink jet printing, and their testing showed no perceivable difference in print quality whether there was an even number relationship between ppi/dpi or not. Since the reasoning behind this belief has always made sense to me, I continue to print files on my Epson at 240ppi. After reading Lanny's post, I reprinted one of my pictures at 300ppi, and there seems to be a slight difference in favor of the higher resolution in spite of the math - maybe - I'm not sure - no, wait a minute.....
I too have found my 300 PPI prints from my Epson printerrs to be a little bit sharper than my 240 PPI prints -- but as Perter so eloquently points out, you need to study them at very close range side-by-side to see it. I cannot see any difference between 300PPI and 360PPI, so I have defaulted to printing at 300PPI for everything 24x36 and smaller. I use 240 or even 180 for larger prints. For certain images where the lens or my technique was not the best, I will print at 240 or less thereby "camouflaging" some of these anomolies
) with no visual effects.
People sure are getting ppi and dpi mixed up.
