Q: I can’t seem to sync photos to my 2G iPod touch. I continually get an error message indicating there is not enough free space, yet my photo folder is only 60 MB and iTunes indicates that I have 240 MB free space left on my iPod touch. This seems to have started after my last firmware update. Any ideas on how to rectify this? Thanks.
A: There are a couple of issues here that may be causing this problem. Firstly, iTunes does not copy your photos over to the iPod in their native formats, but actually converts them to a fixed resolution for display on the iPod and stored them as uncompressed bitmaps. This means that in some cases your photos may actually take up more space on your iPod or iPhone than they do on your computer.
In the case of the iPod touch and iPhone, photos are resized to an approximate resolution of 640×480, but are stored as uncompressed bitmaps, which increases the size of each image as compared to the compressed JPG files normally used for photo storage on your computer. Further, iTunes also creates pre-sized thumbnails for each photo and stores these on the device alongside your original photos. The result of all of this is that you can expect each photo on your iPhone or iPod touch to take up approximately 672 KB of storage per photo.
The second issue you will run into when loading any content onto your iPod touch when running low on capacity is that iTunes tries to leave a little bit of space on your device to avoid filling it up completely. This is especially important with the iPod touch, as other applications may need a bit of space available to run properly.