Did Canon Just Give the New T4i Clean HDMI Out?
Yes and no. One of the most requested features from Canon for its popular DSLRs is the ability to record the HDMI feed coming out of the camera. Nikon has delivered on this feature request, and the D800 and D4 both deliver a clean HDMI feed without any text that allows you to bypass the internal codec and get a clean 1080p 8-bit 4:2:2 image. The first reviews for the Canon T4i were with pre-production cameras, and some had been reporting that the HDMI was completely clean. This could have been chalked up to beta firmware, but now there are real production cameras in the wild and we have a final verdict on whether or not we can record that signal.
Sebastian over at cinema5D had posted that Johnnie Behiri was using the camera and had confirmed that the HDMI was clean. There were issues, however, and the image wasn't quite working correctly. He was using a pre-production camera so I didn't think it made sense to post until people were able to test this using final cameras. Johnnie posted this video of footage (which looks rather nice, and recorded in-camera):
We now have word from online rental company Hire a Camera that the HDMI is indeed clean. Unfortunately, that's where the excitement ends, because the image does not fill the entire screen. Much like the 5D Mark III issue I had talked about in my review, the T4i does not fill the entire screen in liveview mode (but I would assume that it does in playback mode since this is the way that the Mark III works). Here is what the T4i can produce from its HDMI while recording:
Unfortunately that red dot is on screen, so it must be cropped out if you want that final image to be usable. What's the final resolution after cropping? Much lower than 1080p -- 1527 by 868. Also of note, that if anything is changed during recording, the overlays come back on screen and would certainly ruin the recording. The only question that remains is what that final signal is -- whether we've got progressive or interlaced.
I don't think anyone really expected this feature to make its way into bottom-end camera, but it would have been quite the selling point. It seems like all of the new cameras from Canon should be able to output the entire 1080p image while recording, but it's possible that the image processors can't handle anything above that window-boxed image. The 1D X should be capable since the 1D C can do it (and they are virtually identical internally), but that camera has been intentionally crippled and does not have clean overlays and a full 1080p signal. What does Canon gain from crippling these cameras? For one thing, it seems that their video and photo divisions are trying not to step on each others' toes, and there's no question that the margins are far higher on video products.
The only hope that we have is for hackers like Magic Lantern to find the code for full 1080p out of the HDMI and enable it, while also removing the overlays. We should know sometime in the next 6-12 months if this is a possibility as Canon will surely release at least one firmware update for the T4i. At the moment, Magic Lantern for the 5D Mark III is in its infancy, but we will know soon enough if that window-boxed 1080p signal can be made full screen and recorded.
What do you think, would you have bought a T4i just for the ability to record the full 1080p HDMI signal? Let us know in the comments.