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?
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.
I do not want to add to the confusion but
1 pixel == 1 pixel
therefor, on screen =>email@example.com == firstname.lastname@example.org (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
=>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
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!