synchronized photos are taking up more space on iPhone 4 than 3GS - is something

[juandule]

old phone: iPhone 3GS, 32GB, iOS 5.0
new phone: iPhone 4, 32GB, iOS 5.0.1
Mac: MacBook Pro 13", aluminum unibody, mid-2009, 1TB HD, 4GB RAM, OS X 10.6.8, iTunes 10.5.1.

So I had an iPhone 3GS that I was using happily. At that time, the photos that I synchronized from my MacBook Pro took up 5.1GB of space on my iPhone (original total size of photos: approximately 125GB). Then I bought an iPhone 4. I backed up my iPhone 3GS one last time, then restored my iPhone 4 using the backup. On the iPhone 4, the photos now take 12.6GB of space! Here is a comparison of the phones and how much space is taken up by various parts:


iPhone 3GS
Audio - 12.10 GB
Photos - 5.10 GB
Apps - 1.92 GB
Books - 0.01 GB
Other - 1.50 GB
Free - 7.90 GB

iPhone 4
Audio - 12.10 GB
Photos - 12.60 GB
Apps - 1.8 GB
Books - 0.01 GB
Other - 1.94 GB
Free - 0.17 GB


I put the iPhones side by side and went through the albums and they both had the same albums, and all albums had the same number of pictures, except that I noticed that certain videos sync on the iPhone 4 that did not sync on the 3GS, but this accounts for only 186.5 MB of the difference.

Maybe iTunes does not compress the photos for the iPhone 4 as much as it does for the iPhone 3GS because of the higher resolution display of the iPhone 4?

I'd really like to reclaim that 7.8 GB of space. Any thoughts?