If you purchase only standard definition (SD) video content via your iTunes account, then this article will not apply to you.
For those of you that purchase the high definition (HD) content, you also have the ability to download the SD version at no additional cost. But how do you achieve this when the purchased area of iTunes, on the iPhone, only lists the HD version?
It is important to note that the iPad version will give you the option between HD and SD from within the purchased area of the iTunes app. Unfortunately, this option is not present for the iPhone.
To work around this limitation, on the iPhone, you will need to search the iTunes Store for the movie title listing. In this case, it will be for the movie Casablanca.
When you tap and subsequently expand the movie information there is a new section at the very bottom of the entry that is titled Also Available in Standard Definition.
After tapping on the Also Available in Standard Definition button the entry changes and the HD icon disappears. If you now tap on download, you will be downloading the SD version of the film. Of course, should you wish to download the HD version, it will be available at any time, from any of your devices, including the iPhone in this example. Therefore, this option does not make any permanent changes to your purchased content.
Downloading the SD versions of your purchased movies or television shows will take up significantly less storage space on your device. The download data requirement will also be reduced when choosing SD content. For example, Casablanca in HD consumes 3GB of storage, while the SD version is only 1.1GB of storage.
If you travel, or just want more content on your device, this tip is likely to come in useful.
This tip is also valid for television shows from the iTunes Store.