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Old Feb 8, 2004, 5:16 AM   #1
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Default p.p.i. what!?

From what I gather, there is a standard p.p.i. in which prints should be printed, correct?

If so, I'm somewhat concerned as when I put my tif image in my photo editor, click on "image information" each image registers at 72 p.p.i.

Should this be changed when I go to print 4x6? Currently I have a hi-ti 630pl and so 4x6 is the only print size I'll be making until I get an ink-jet printer.

The more I get involved with this (digital cameras, printers & editors)...the more I realize how much learning I have yet to do!

Currently I am using psp 7.04 but will soon be using ps7 ( ).
So, if anyone has a link discussing image resizing in ps7...I'd appreciate it, too.

~informativeNOT :P
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Old Feb 8, 2004, 6:06 AM   #2
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Default ppi & dpi again

The "ppi" or "dpi" figure is just an arbitrary piece of fairly useless information attached as non-image data to your image files. It doesn't affect the image or image quality at all, unless you actually use it in your printing package, which you're unlikely to do. It's the number of pixels that count.

When you come to print your images, it's a good idea to use at least 200 or 300 pixels per inch, if you have sufficient of them. If you're not too fussy (e.g., it's a giant print to be viewed from a fair distance) you can get away with a lot fewer. How many pixels you've got per inch on the print depends only on the number of pixels in your image, and the size at which you tell your printer to print it. The embedded "dpi" figure is an anachronistic, historic irrelevance.

You can alter the default dpi figure in PSP7 if you really want to, under "Preferences" somewhere. However it's not worth bothering if the "Print Setup" arrangements are allowing you to size your prints to suit your needs.
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Old Feb 8, 2004, 4:18 PM   #3
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Thank you Alan for your response, I appreciate it.

Quote:
The "ppi" or "dpi" figure is just an arbitrary piece of fairly useless information attached as non-image data to your image files.
I have heard similiar opinions...yet, it seems everyone is changing the p.p.i.

My two concerns are, regarding p.p.i. is:

1) Having an unedited, uncompressed picture in tiff format, taken with a 4 mp camera, reading 1600x1200, superfine and at 72 p.p.i.

...is 72 p.p.i. the standard, straight out of the camera? Considering my camera.
(To note, I "save as" right from my canon zoombrowser ex.)

2) When printing up to 8x10, would a p.p.i. above 72 be noticably better?

Naturally, I would like to get the best print possible Due to the size of prints, they would be seen up close.
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Old Feb 8, 2004, 4:35 PM   #4
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Default 72 ppi

It seems to be the standard. I have two FinePix cameras (1400 and S602Z) and both cameras take pics at 72 ppi.

The size of the file is what makes the pics different. When I open a 480 x 640 pic using my photo editor, the height sets to 6.67 inches and the width to 8.89 inches.

When I open a 960 x 1280, the height is 13.33 inches and the width is 17.78 inches.

Twice the pixel size, twice the inch size, but the ppi remains 72.
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Old Feb 8, 2004, 4:43 PM   #5
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Jerry, thank you.

Phew, that is a relief to hear! I was afraid to be rudely awakened to the fact that all the pictures "saved as" from my camera's software...were saved at a low p.p.i. when they could have been saved at a higher p.p.i.

Thank you for the information...I can breath a little better now
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Old Feb 8, 2004, 6:30 PM   #6
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I think the point has been lost. The PPI setting is actually irrelevant as it does not affect print quality.
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Old Feb 8, 2004, 8:02 PM   #7
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Most digicams produce very large canvas sized images that are 72 ppi. When you resize the images to higher PPI (print quality is 200 and above). The image size decreases. If you take a 6 mega pixel image and increase the PPI to 300. The print size is less than 8 x 10. However, I've gotten excellent 13 x 19 prints from my 5 mega pixel Nikon 5000. I really can't tell much difference from in pixellation between it and my Canon 10D at most print sizes.

Bill
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Old Feb 8, 2004, 10:18 PM   #8
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luisr wrote:

Quote:
I think the point has been lost. The PPI setting is actually irrelevant as it does not affect print quality.
Hearing two sides creates confusion. Who's right and who's wrong? lol
I hear people say as you have and yet, I hear many people say they increase p.p.i. to 200-300.

wsandman1:

Quote:
When you resize the images to higher PPI (print quality is 200 and above). The image size decreases.
So those who increase p.p.i. are doing so to have a smaller image, a smaller printed picture?

Quote:
I really can't tell much difference from in pixellation between it and my Canon 10D at most print sizes.
Maybe I'm going to have to tinker. On the monitor, I don't see any difference but if I recall, the monitor can only "register" so much?

I get a little "batty" when I can't figure something out. :roll:
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Old Feb 8, 2004, 10:47 PM   #9
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from what I gather:
dpi = dots per inch is related to the picture in a print medium
ppi = pixels per inch is related to a picture displayed on a monitor

72 ppi is very common for the web but does not directly correlate to the printed picture as far as size is concerned. I believe it does correlate to the overall resolution.

My brother in-law owns his own graphic arts shop and tells me that anything over 300 dpi is a waste of time because that is essentially the effective limit of inkjet printers. In fact he says that national geographic prints at 200 dpi and at his shop they mostly scan images at 200 dpi with 300 dpi being the upper limit.

Anyway here are a couple of links which may do a better job of explaining.

http://graphicssoft.about.com/librar...y/bldefppi.htm
http://www.webdevelopersjournal.com/...s/ajs_ppi.html
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Old Feb 8, 2004, 11:02 PM   #10
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I just read some of the links I posted. Should have read them prior to giving my two cents because I short changed you.

I think this link explains what is going on with your particular situation and the picture always opening at 72 dpi.

http://graphicssoft.about.com/cs/dig...eprintsize.htm

Taken from the link:

A. Many digital photos will open into your photo editing software with a resolution of 72 ppi. This is either because your digital camera does not store resolution information when it saves the photo, or the software you are using can't read the embedded resolution information.
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