You can stream from iPhoto on your iPad to your HDTV via Apple TV. The trick is to reveal the hidden AirPlay button while working in iPhoto.
First, make sure that "mirroring" is enabled in iPhoto for iOS. You can check by going to the Albums page, clicking on the gear menu in the upper right corner, and sliding the "ON" button for "Mirror on TV."
Then double-tap the home button to reveal all the apps that are currently active in the Dock. If you swipe the dock to the right, it will reveal your media controls, as shown in the illustration above. Tap the AirPlay button, choose "Apple TV," double-tap the Home button again, and iPhoto for iOS will be mirrored on your HDTV.
Now you can share images with friends and play slideshows on your HDTV directly from iPhoto. And since Apple TV is so portable, you can easily pack it in the suitcase when traveling on vacation.
You can find more photo tips and "photography how tos" on my Pinterest page.
A lot of people - even Apple TV owners - don't seem to be aware of this cool AirPlay functionality. My wife was surprised when I showed her how her Fitness Class app can do this as well. And, even with non-AirPlay-aware apps, iOS's built-in mirroring lets you mirror your iPad/iPhone screen onto your TV - so every app can do basic mirroring!
Maybe Apple needs to make a bigger deal of this.
I totally agree. There are many, many uses for this once you know it is there.
This is not a full screen photo streaming solution and can be done with any running apps. I mean AirPlay mirroring is a system wide option.
Even with native 16:9 photos what you get is a smaller window in the center of your TV screen.
Real AirPlay ready apps feature an in-app AirPlay button and the output is customized for a widescreen HD TV. It really sucks that you can't do that with photos at least in Apple apps. I paid for iPhoto just because Apple claims it can stream photos via AirPlay to my Apple TV. Instead there is only AirPlay mirroring to do something similar, but that is available for everything.
I just tested this and it does actually work as we would hope. The photos are displayed in full screen with a small black border on my HDTV but still a good looking slide show. The black border looks like it is meant to be there rather than being an aberation. The iPhoto controls are displayed only on the iPhone and the photos themselves are beamed to the TV screen. When you swipe a photo it works as expected and slides to the next photo on both the iPhone and the TV screen. This is "proper" support and turns the iPhone in an excellent presentation control for a photo show.