Searcher Loc: Kent, England

Well I got something right then :)

RichieC Loc: Adirondacks

OK, I guess I knew this- as all images change physical size as the screen resolution changes. But I never bothered to actually figure it all out., Wasn't important because the art and images I have created for web use, is always at a certain dpi x dpi or a percentage of page width, and was not overly concerned with inch dimensions.

However I will argue a bit and prove.. that 72ppi is still the default standard, and the early crt's used this as a measure when they were built as it is a printing standard from well before computers. 12 points per pica, 6 picas per inch 72 points in an inch, etc. The early crt's aim was to match on screen what the printed page looked like... namely the original Macs.

So heres some proof- albeit perhaps a holdover. I have photoshop CS6, open a file at 4" x 4" at 109 and it will measure 4" x 4" on my month old mac 27" display ( not bragging, just not some old screen) , now save this using Photoshop's "save for web" command, (a particularly handy tool for optimizing images and using a file size saving compression amount- and compare tiffs to gif's to png, etc. one I will continue to use) and reopen the resulting jpeg, will now say 72dpi. Some quick math and I will simply start with a larger image dimension to end up where I want if I need it to appear at a specific inch dimension.

I did learn something! LOL never too old...

Searcher Loc: Kent, England

There is a website called "72dpi" and they also talk of the mac monitor being 72dpi etc. What they don't explain is that although Macs were made available in 1984, IBM PC's were available in 1981 complete with a CRT monitor running with a screen dpi of - 72.

The web page goes on to say that though 72dpi is often set in graphics programs by default, it is more tradition than science these days.

My 4 x 4 image in Photoshop measured 4 x 4 on my screen at 100 dpi (I have a lower res screen than you) but interestingly, the same image in Elements only came to 3.75" square. (both designated at 100%)

It's all a bit academic though - if it would stop raining I would go out, shoot pics and not worry about such things.

CaptainC Loc: Colorado, south of Denver

Yeah, yeah, I know Photoshop's Save for web thing does the silly 72PPI thing. It does no harm, but does no good either. Sorry, but Adobe is wrong. You have not proven a thing except to prove Adobe is out of date. :-)

Really, as far as SCREEN display goes, the PPI is NO MATTER.

Jeez, just prove it to yourself: send yourself an image at any dimension you want- let's just say 640x800. Send one at 72PPI and one at 357 or whatever. They will be the same size on the screen. If your screen has 109 pixels to the inch, it will be 5.87 inches wide. If your monitor has 96 pixels to every inch it will be 6.67 inches wide. Good luck finding ANY recent monitor with a 72 pixel per inch pitch.

Remember, this has no bearing on printing the file - just the digital display of the file.

RocketScientist Loc: Littleton, Colorado

I knew as I was typing that, I shouldn't have mentioned it. The last time I gave a damn about ppi on a monitor was 12 years ago.

GHK Loc: The Vale of Eden

The above interesting information can lead us to an understanding of many of the misconceptions which exist concerning inkjet printing. The figures differ widely but there are, I am sure, good reasons for each in its own situation.
Inkjet printing, too, has its own situation. It works by putting down an array of ink dots on the paper. The better Epson priters use 1440 dpi in one direction and 1440, or a small multiple of it in the other. Image resolutions for printing are, for obvious reasons, much lower. However, the printer has to match them together and the task is made much simpler if the 1440 dpi of the printer is an exact multiple of the print res. in ppi.
Thus, 360, 288, 240, 180 ppi, etc (down to 90, although quality loss may be evident by that stage) are the best choices, dependant on the size of print required.
Note that 300 ppi, which is often recommended, is not really suitable (although it may be if the printer resolution is a multiple of 300, which, I am given to understand, is the case with Canon printers). The Epson will still print from a res. of 300, but you are, almost literally, trying to put a square peg in a round hole.
I strongly suspect that the suggestion of 300 ppi as a sort of standard came from professionals, who were used to sending their work to be printed on offset litho machines.

GHK

dvblair2003 Loc: Blountstown Fl

Reading this made my head hurt.