Image resolution for printing
Sep 5, 2012 14:06:09 #
My JPEG pix's are 72 pixel/in and 72X48 in. size and 3456X5184 pixels width and height. When I reduce the size for prints I say 11X7.333, the pixel dimensions change to 528X762. I have been increasing the resolution from 72 to 150 to raise those numbers in hopes of getting higher res. prints. My prints are coming out very nice but I wonder if I am accomplishing anything by doing this. I'm an old film photographer and although I've been shooting digital for a few years now I don't quite have a handle on the pixel and printing side of things. Everything else is about the same as far as exposure etc.
Sep 5, 2012 15:21:51 #
OK - here is what you need to understand: JPGs are not 72PPI - that is what your software is making them. All that matters is pixel dimension. So, if the file is 3456x5184 and you try to resize it to 11x17 and leave RESAMPLE checked, it will make the image 11x17 and 72PPI. If you uncheck RESAMPLE, type 300 in the PPI box, you will get a file that is 11x17 @ 300PPI.
I know - moving to digital has some bumps and this is one of them. If you remember that your camera just delivers an image that is X pixels wide and Y pixels high and that WE are the ones that set the Pixel density (Pixels per Inch - PPI), then things start to get easier. A camera has no knowledge of PPI - our software does.
To make a decent print, you really need to be 180PPI or denser. 240 to 300 is the norm.
I know - moving to digital has some bumps and this is one of them. If you remember that your camera just delivers an image that is X pixels wide and Y pixels high and that WE are the ones that set the Pixel density (Pixels per Inch - PPI), then things start to get easier. A camera has no knowledge of PPI - our software does.
To make a decent print, you really need to be 180PPI or denser. 240 to 300 is the norm.
Sep 6, 2012 07:07:36 #
CaptainC wrote:
OK - here is what you need to understand: JPGs are... (show quote)
Glad he asked that question - that information provided by the Captain is really useful!!
Sep 6, 2012 11:12:51 #
Follow up question: Is there any benefit in printing at a higher resolution than 300 ppi? Thanks, Cap
Sep 6, 2012 11:29:55 #
JerseyMan wrote:
Follow up question: Is there any benefit in printing at a higher resolution than 300 ppi? Thanks, Cap
Absolutely none. In fact, 240PPI is usually plenty and if you print on Canvas, you could go as low as 150.
Sep 6, 2012 11:30:24 #
Sep 6, 2012 11:35:31 #
Good rule of thumb for color image printing is 200 DPI your monitor is 72 DPI, if you are really paranoid about losing quality then you can go 250 or 300 DPI anything higher than that you are just making your task of printing harder and it will not have any effect on the print quality...
Sep 6, 2012 13:30:29 #
Blurryeyed wrote:
Good rule of thumb for color image printing is 200 DPI your monitor is 72 DPI, if you are really paranoid about losing quality then you can go 250 or 300 DPI anything higher than that you are just making your task of printing harder and it will not have any effect on the print quality...
What in the world does 72dpi on a monitor have to do with printing PPI? Most monitors are NOT 72DPI, by the way.
Sep 6, 2012 13:53:14 #
CaptainC wrote:
What in the world does 72dpi on a monitor have to do with printing PPI? Most monitors are NOT 72DPI, by the way.
Blurryeyed wrote:
Good rule of thumb for color image printing is 200 DPI your monitor is 72 DPI, if you are really paranoid about losing quality then you can go 250 or 300 DPI anything higher than that you are just making your task of printing harder and it will not have any effect on the print quality...
What in the world does 72dpi on a monitor have to do with printing PPI? Most monitors are NOT 72DPI, by the way.
Thankyou nice to have a hall moniter, I guess that I should have said that most monitors default to 72 dpi or ppi whichever of the two terms that you prefer. In the commercial printing business it is often referred to as DPI and not PPI... the only reason that I even used the term is that his camera is defaulting to 72 ppi which is the same as the default setting as many of video monitors. I guess that was not helpful. He should simply when he resizes set his ppi for 200, or better yet if he should just specify the size of the print in his print command and instruct his software to print to the size of the print allowing the file to retain it's original resolution.
Sep 6, 2012 13:58:40 #
CaptainC wrote:
What in the world does 72dpi on a monitor have to do with printing PPI? Most monitors are NOT 72DPI, by the way.
Blurryeyed wrote:
Good rule of thumb for color image printing is 200 DPI your monitor is 72 DPI, if you are really paranoid about losing quality then you can go 250 or 300 DPI anything higher than that you are just making your task of printing harder and it will not have any effect on the print quality...
What in the world does 72dpi on a monitor have to do with printing PPI? Most monitors are NOT 72DPI, by the way.
Cap - It has always seemed to me that "pixel dimensions" could be regarded as the actual size measurement, and the "resolution" dpi is simply the dividing factor to determine size for printing (I always try to shoot for printing @ 300dpi if possible). Does "resolution" setting really effect any display/output other than printing? It seems like the 72dpi for displays is just an arbitrary "convention" these days...
Sep 6, 2012 14:09:32 #
jazzplayer wrote:
quote=CaptainC quote=Blurryeyed Good rule of thu... (show quote)
The whole 72PPI/DPI thing is an internet myth. It has nothing to do with anything. Screen resolutions are 72, 92, 96 etc.
There is this myth that if you size it to 72PPI (NOT DPI) that it will not print well - baloney. If I send you a file that is 2000x3000 pixels at 72PPI, you can resize that to 240PPI and make a beautiful 8x12. The 72PPI meant nothing.
However, if I send you a file that is 450x630, you can size that to give a reasonable 5x7, but at 8x10 it falls apart. Yes, there is software that can do a decent job of repair, but there are limits.
ALL that matters for image quality is pixel dimension - then you make the PPI whatever you want. 240 to 300 makes great prints. 150+ for Canvas. Even 72PPI can look decent from 30 feet!
Sep 6, 2012 14:39:36 #
CaptainC wrote:
quote=jazzplayer quote=CaptainC quote=Blurryeye... (show quote)
We are all basically saying the same thing here, the file should be sized no smaller than 200 ppi or dpi of the targeted output.. pretty simple so if you want to print an 8 x 10 your file size should be no smaller than 1600 x 2000 pixels... some people like to make their file sizes a little larger as they do not trust 200 ppi on the targeted output size to give them the best quality.. I was in the digital printing business for several years, please excuse me for referencing the language we used when discussing files for output. Your are right that the 72ppi is pretty much meaningless when it comes to output for printing but for some reason that is the way that the information is expressed in our EXIF data... and it has also always been understood that it is the lowest size that you should make your file for monitor viewing, ie if you want your file to at sharply at 10" wide on a monitor, then the width of your file should be no smaller than 720 pixels..
Sep 6, 2012 15:01:51 #
Blurryeyed wrote:
...
We are all basically saying the same thing here...
We are all basically saying the same thing here...
I agree! - But it never hurts to looks at it from a bunch of different angles. I know it took me finding a few different perspectives before the size-vs-resolution thing finally clicked.
Cap - I agree that 72dpi CAN print okay, but at that resolution it starts to depend a lot on the printer. In my experience, cheaper printers can do a relatively okay job - probably because the expectations are pretty low to start with, whereas big high-speed presses, not so much. I used to prep press-ready PDFs for high volume presses, and the commercial printer REQUIRED files rendered at 300dpi, period. Most of the source images would be "forced" to 300dpi (resampled) from some other resolution upon PDF creation.
Sep 6, 2012 15:15:17 #
Blurryeyed wrote:
quote=CaptainC quote=jazzplayer quote=CaptainC ... (show quote)
Right - 720 PIXELS - not any PPI reference.
Sep 6, 2012 15:17:58 #
jazzplayer wrote:
quote=Blurryeyed ... br We are all basically sayi... (show quote)
It is true that some printing devices prefer a specific PPI for best results. The good inkjets do an amazing job of doing just fine with 180, 240, 300.
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