How do I set to 300 DPI when exporting?

Question

Level 1

8 points

How do I set to 300 DPI when exporting?

I have a real problem here. I use an Apple iMac with the base software, iPhoto.

When I export and burn to a CD, the photos are evidently being exported at a very low (72) DPI. I've had complaints from publishers and a stock agency that my images are not at 300 DPI. Yet I cannot figure out how to set DPI when exporting.

One stock agency owner told me to click on "preferences" and look there for where to set DPI. I did so, and found nothing whatsoever about DPI settings. He (the stock agency owner) doesn't use an Apple, so he was probably basing his "preferences" suggestion on where one would go if they were using a Windows-based program, or if one were using Photoshop.

If anyone can tell me how to set the DPI using the software I have I would appreciate it. I don't need to know how to do this in Photoshop or Aperture, as I don't have these programs, and I do not intend to get another editing program. How do you do it using only iPhoto - that's my dilemma.

Thanks!

Mac OS X (10.5.6), iMac "extreme" 24" monitor

Posted on Jul 5, 2009 7:37 AM

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Answer 1

LarryHN

Level 10

106,142 points

Jul 5, 2009 9:18 AM in response to Tom Reichner

DPI means nothing in a digital file - it is just a number - the critical thing is the pixel size of the photo - Read +The Myth of DPI+ - http://www.rideau-info.com/photos/mythdpi.html

DPI (dot per inch) is only meaningful when displaying or printing - then the number of dots (pixels) divided by the display in inches gives you dpi

iPhoto does not give you control of the meaningless number DPI - some programs like Photoshop do

but it is still meaningless until you display and then the inches of the display control it

LN

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Answer 2

Old Toad

Level 10

216,854 points

Jul 5, 2009 9:32 AM in response to Tom Reichner

Tom:

DPI only comes into play when you set a size to be printed. Say you have an image that is 1600 x 1200 pixels in size. iPhoto when exported would report it at 72 dpi and a print size of 22.22 inches x 16.66 inches. If you you wanted a 300 dpi print from that photo you would have to print it at 5.33 inches x 4 inches.

It doesn't make any difference what the dpi is reported as long as the pixel dimensions are large. What size prints are offered by the stock agency? Take the largest that you photos would be offered at and multiple each dimension by 300 to get the number of pixels you would need to provide in the file. For example an 8 x 10 would require a minimum of 2400 x 3000 pixels. An 11 x 14 - 3300 x 4200 pixels.

To get a photo to report a specific dpi it must be set to be printed at a particular size. Photoshop can do that. The print size is included with the other info embedded in the file that would let other image applications see the dpi and the print size. For more info on this read The Myth of DPI. Watch this video screenshot of changing the dpi of a photo in Photoshop. Watch as the print size changes with dpi changing but the pixel dimensions remain the same.

iPhoto cannot set the print size for exporting.

Bottom line: if you were to provide an image at 3300 x 4200 pixels (an 11x14) it should be sufficient for any size up to that size. Photoshop Elements for Mac, at $79 (Amazon.com) has about 75% of Photoshop's capabilities at 1/7 the cost. It's really a very powerful, consumer oriented image editor. Ask them what the minimum pixel dimensions are for the photos.

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Answer 3

Tom Reichner Author

Level 1

8 points

Jul 5, 2009 9:40 AM in response to Tom Reichner

Hey, guys - thanks for responding.

I realize that DPI doesn't really mean anything - however, several publishers insist that the images be pre-set to 300DPI, and will not accept images that they have to reset themselves. That's why I need to have them already in 300 DPI format when I export them. Publishers and stock agency personnel simply do not want to have to do anything themselves that they feel the photographer could do himself.

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Answer 4

LarryHN

Level 10

106,142 points

Jul 5, 2009 10:02 AM in response to Tom Reichner

Then you need a third party application

here are links to some to check out.

LN

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