Previous 1 2 Next 18 Replies Latest reply: Nov 10, 2012 5:35 PM by vinnyvg Go to original post
  • YouriPadBookDotCom Level 1 Level 1



    I was reading the boards and saw this:

    "The original iPad and iPad 2 have 132dpi, the new iPad has 264dpi.


    If you want high-resolution for the new iPad, 264dpi will give you the best possible image quality."


    But above, it's said over 72 dpi is too much?


    What's the best dpi to use for photos?


    Also, what size dimensions do I use for each photo for a full page photo gallery?


    Many thanks!


  • vinnyvg Level 4 Level 4


    The replies  in this thread give you a lot of information, options and choices.


    I have used 2048 x 1496 at 150ppi  or dpi whichever you prefer. The image dimentions  are accepted by the review team and when expanded on my New iPad - they expend and look good on retina display.
    I am happy with that and unless the review team ticket a book  with this issue, I will continue  using this image format.


    If you have doubts about how the images look, format at different settings, insert into a test book and check out the diplay on your iPad.


    If you submit a book that is ticketed for image size issues, then you have a conduit to the  review team to get a solutuion.


    Full Page Photo size -  the iBA page in landscape is 1024 x 748 so that your  full page  photo size.

  • Yleb Level 1 Level 1


    I do not want to add to the confusion but

    1 pixel == 1 pixel



    therefor, on screen =>1024x768@72ppi.jpg == 1024x768@300ppi.jpg (weight and quality)



    also, 2048x1596.jpg > 1600x1200.jpg > 1024x768.jpg (weight and quality)



    you noticed that in iba, images's sizes are in "pt" not in pixel and

    The desktop publishing point (DTP point) is defined as 1/72 of the Anglo-Saxon compromise inch



    =>in 72 dpi : 1pixel = 1pt



    when you cogitate your workflow

    for scanning images, dpi is important (not less then 300)

    for printing images, dpi is important (200 for desk print, more than 300 for professionnal press)

    for screen, dpi is not important and photoshop save for web is the good way

  • vinnyvg Level 4 Level 4

    I agree Yleb,  higher resolution  only  has real significance if printing  the images - the more dots.points/pixels per inch - makes an enlaged image  sharper. 


    To explain, after long  to'ing and fro'ing replies with the iBook Support team, and not really getting  anything  more positive that " Apples requires images NOT to exceeed 2 million pixels" I applied whe  the English call....Irish logic! 


    The retina display "sharper" the the iPad / iPad 2 i.e.  greater resolution because its physically the same  size.

    Support will advice to teh effect " images of :-

    1024 x 767  or 1024 x 748

    2048 x 1496 or 2048 x 1536    these are landscale swith around for Portrait.


    The first size caters for none retina, the second caters for all iPads.


    The next consideration for me  came about after a ticket  stated images were to small and when expanded became blurred. So to cater for Retina and expanded images - I simply made the reolution greater to  maintain a sharper image when enlarged.

    As I only make photo books, I will attract other photographers who wil be critical of image quality.


    The thing to take acoount is deal with  your audience first.  If you are  displaying only 1024 x 748 at 72ppi  - expanded on Retina they look blurred.


    This is from the Retina iPad page, Apple store:-


    • Retina display
    • 9.7-inch (diagonal) LED-backlit Multi-Touch display with IPS technology
    • 2048-by-1536 resolution at 264 pixels per inch (ppi)
    • Fingerprint-resistant oleophobic coating


    That seems to  answer all questions about image sizes to use..and contradics all  those who say that 1024 x 768 at 72ppi  OK for all iPads.


    Finally,  Apples mantra is  no images greater than 2 million pixels - BUT 2048  multiplied by 1536 = 3,145,738 pixels!

Previous 1 2 Next