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04-01-2010, 12:35 PM   #1
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resolution problems

hi everyone-
I was working on some pictures today in photoshop CS4 and noticed that the photos are pretty grainy. I shot them with a kx, kit lens 18-55. The phtoto is of a group of 3 men, one sitting.
As I started looking at the picture info, I noticed that the ppi was only 72. WTH? I am at work, so I don't have the camera or manual in front of me, but is there something I need to change in my settings to get this up?
-thanks in advance.

04-01-2010, 12:39 PM   #2
Ira
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QuoteOriginally posted by slcoleman99 Quote
hi everyone-
I was working on some pictures today in photoshop CS4 and noticed that the photos are pretty grainy. I shot them with a kx, kit lens 18-55. The phtoto is of a group of 3 men, one sitting.
As I started looking at the picture info, I noticed that the ppi was only 72. WTH? I am at work, so I don't have the camera or manual in front of me, but is there something I need to change in my settings to get this up?
-thanks in advance.
Maybe if the 4th guy stood up it would have come out cleaner.

Is this another Mod April's Fool Joke?
04-01-2010, 12:42 PM   #3
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Ignore the ppi. It's meaningless. It has caused more confusion than it's worth.
04-01-2010, 01:06 PM   #4
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I love it when people ask this, because then I get practice trying to find the shorest and clearest answer. Here's my current attempt:

The number stored in the EXIF is irrelevant. A camera doesn't have pixels per inch; it has pixels, period. Only when you go to print the image can you then divide by the size in inches to find out how pixels per inch you have. But since the EXIF standard does have a field for PPI (which *is relevant for scans, if not for digital photographs), the camera has to put some number there. The EXIF standard calls for cameras to use 72 there, but it doens't matter. the actual resolution when you print will be the number of pixels divided by the print size.

04-01-2010, 01:17 PM   #5
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QuoteOriginally posted by Marc Sabatella Quote
I love it when people ask this, because then I get practice trying to find the shorest and clearest answer.
Try again, Marc. I thought I knew what ppi was. After reading your reply, I realized that I didn't really know

You have more patience than I do. My standard answer is, "Ignore it."
04-01-2010, 01:39 PM   #6
graphicgr8s
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QuoteOriginally posted by Marc Sabatella Quote
I love it when people ask this, because then I get practice trying to find the shorest and clearest answer. Here's my current attempt:

The number stored in the EXIF is irrelevant. A camera doesn't have pixels per inch; it has pixels, period. Only when you go to print the image can you then divide by the size in inches to find out how pixels per inch you have. But since the EXIF standard does have a field for PPI (which *is relevant for scans, if not for digital photographs), the camera has to put some number there. The EXIF standard calls for cameras to use 72 there, but it doens't matter. the actual resolution when you print will be the number of pixels divided by the print size.
Do we have to go there again?

To the OP:

Look at the PPI but also look at the canvas size. Turn off resample and plug in 300 or 240. The canvas will shrink to a more "normal" size with the same amount of pixels. You've told PS to make the pixels smaller which in turn, since you're not eliminating any pixels does two things.
1. It decreases your canvas size.
2. It sharpens the image since you now have smaller pixels. (At least when you print.)

Never let a printer change your ppi/dpi. Do it right in photoshop.
04-01-2010, 02:45 PM   #7
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nope, no april fools, Just a newbie. I was confused since there was so much noise in the photo, but I had to take some sample shots trying to get the ISO just right. Unfortunately, all the test shots looked the best. The subjects were less than cooperative!
Thanks for your assistance everyone! I will take the info to heart.
04-01-2010, 04:11 PM   #8
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QuoteOriginally posted by slcoleman99 Quote
nope, no april fools, Just a newbie. I was confused since there was so much noise in the photo, but I had to take some sample shots trying to get the ISO just right. Unfortunately, all the test shots looked the best. The subjects were less than cooperative!
Thanks for your assistance everyone! I will take the info to heart.
I apologize, but this IS a complicated concept to grasp.

A 10 inch by 10 inch image at 72 dpi will be 5 by 5 at 144...2.5 by 2.5 at 288...etcetera.

WITHOUT resampling in an image editing program like Photoshop or other.

04-02-2010, 11:00 AM   #9
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QuoteOriginally posted by SOldBear Quote
Try again, Marc. I thought I knew what ppi was. After reading your reply, I realized that I didn't really know
OK, bummer, then :-).

Still, hopefully we all agree on bottom line: it's normal for an image from a digital camera to claim to be 72ppi. In fact, any camera conforming to the EXIF standard will report that. The OP seemed to be having some other sort of problem he hoped to pin on this, but this isn't the problem. He'll have to keep looking to find answer to that problem (and posting more info on the problem would help - but in a different thread).
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