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Photography Question 

dpi and resolution

I am giving printed home portraits for gifts and the person who does them asks for a minimum of 1500 dpi for each photo sent to him by e mail. Most of the photos I have not taken myself but have been sent to me by e mail by relatives. I do have PhotoShop 9.0 as a new software on my computer and would like to know how to increase the dpi without distorting the picture or making it so large that I can't send it through e mail?

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10/18/2005 12:20:23 PM

John G. Clifford Jr
BetterPhoto Member Since: 8/18/2005
  1500 dpi? That can't be right. At that resolution a 12 MP camera (top of the prosumer dSLR lineup) would give you a 2.5" x 2" print.

Actually once you get to about 300 dpi or so it's very hard for people to see any differences between that and higher resolutions without being pressed right up against the photograph with a magnifying glass.

Who is doing your printing? What you want is the native resolution of the printer. Most commercial photo printers like 300 dpi. Most home printers (inkjets, dye subs, etc.) like 300 or 360 dpi.

How big are your images going to be (final print size)? What is the resolution, in megapixels, of your camera, and what are the pixel dimensions, e.g., 4000x3000?

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10/20/2005 7:26:27 PM

Martha    You are absolutely right, John. I read the instructions from the artist wrong - "In order to view and process a home Portrait we need a print with a minimum of 150 dpi and a minimum of 5" x 7" in size. (the file you sent is too small, it is 81 dpi and 3.7" x 2.4") Anything less than our minimum specifications makes it impossible to view the details of the home."

But once I have the jpeg on my system how do I increase the dpi to 150 in PhotoShop 9.0?

Thanks for your further help.


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10/21/2005 5:50:32 AM

Jay A. Grantham
BetterPhoto Member Since: 7/21/2005
  Unfortunately it sounds as though you are out of luck.. unless you can get the original files. You can't open an 81dpi 3.7 x 2.4 in Photoshop and just convert it to 150dpi 5x7(you "can" but very poor results).

So, you need the original digital files prior to being reduced for email.. or prints to scan.

Least that is my belief from what I understand you to be saying.


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10/21/2005 7:39:41 AM

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