Editing in iPhoto reduces DPI from 180 to 72

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Level 1

39 points

Editing in iPhoto reduces DPI from 180 to 72

My camera takes pictures at 180 DPI. They are 180 DPI after I import them into iPhoto, however they are reduced 72 DPI pictures after I edit them in iPhoto.

Could someone explain to me why this happens? When iPhoto creates an iBook does the software increase the DPI of the pictures in the book up to 300 DPI?

I need to print my pictures and my print shop has requested 300 DPI. I can increase to 300 using Graphic Converter but would prefer to increase from 180 to 300 rather than from 72 to 300.

Jo Hauser

Powerbook G4 (17inch), Mac OS X (10.4.8), iPhoto 6.0.5

Posted on Jan 7, 2007 5:52 AM

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Answer 1

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SDIllini

Level 6

16,675 points

Jan 7, 2007 6:05 AM in response to Jo Hauser

Hi Jo:

Read what PhillyPhan and Old Toad have posted in this discussion:
http://discussions.apple.com/thread.jspa?messageID=2948441&#2948441

Sue

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Answer 2

Jo Hauser Author

Level 1

39 points

Jan 7, 2007 3:01 PM in response to SDIllini

Sue,

Thanks for the suggestion. I understand a little more but ams still puzzled.

Old toad wrote:

For some reason, the Enhance
function increases the nominal document size (in
inches), which results in fewer pixels per inch.
However, that means nothing when you actually
print.

So my question is: Why does it mean nothing when you print? My print shop requests images at 300 dpi. My Camera spits them out at 180 and then iphoto drops them to 72 dpi. Why do I have to take my image into another application to increase the dpi up to 300 before sending it for printing?

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Answer 3

SDIllini

Level 6

16,675 points

Jan 7, 2007 3:23 PM in response to Jo Hauser

What happens when you do nothing to it and print? Does it print correctly?

Sue

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Answer 4

Jo Hauser Author

Level 1

39 points

Jan 7, 2007 8:12 PM in response to SDIllini

I don't know yet how it prints. It will cost me money to find out because my images are going to a print shop. As the print shop requested 300 dpi I assume they know that it would not print as well at 72 dpi.

Does apple change the dpi when you move an image into a book to be printed by the apple service?

Jo

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Answer 5

Old Toad

Level 10

207,367 points

Jan 7, 2007 8:47 PM in response to Jo Hauser

Jo:

Apple doesn't work with dpi. It works with total pixel dimensions. See Minimum Picture Resolution For Ordering Quality Prints. So if you're going to print a 4 x 6 and want 300 dpi your image size should be around 1200 pixels x 1800 pixels or thereabout. They will take that image file and squeeze it into 4 x 6 which will give your 300 dpi. If they took that same file and printed an 8 x 12 picture the dpi would be lowered to 150. So always think pixels and try to have the largest number of pixels possible in the cropped image.

Do you Twango?

TIP: For insurance against the iPhoto database corruption that many users have experienced I recommend making a backup copy of the Library6.iPhoto database file and keep it current. If problems crop up where iPhoto suddenly can't see any photos or thinks there are no photos in the library, replacing the working Library6.iPhoto file with the backup will often get the library back. By keeping it current I mean backup after each import and/or any serious editing or work on books, slideshows, calendars, cards, etc. That insures that if a problem pops up and you do need to replace the database file, you'll retain all those efforts. It doesn't take long to make the backup and it's good insurance.
I've written an Automator workflow application (requires Tiger), iPhoto dB file backup, that will copy the selected Library6.iPhoto file from your iPhoto Library folder to the Pictures folder, replacing any previous version of it. You can download it at Toad's Cellar. Be sure to read the Read Me pdf file.

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