Constant Image Height home theater viewers take note: VUDU now offers (for free) the ‘Transformers: Dark of the Moon’ teaser trailer in high definition with 21:9 anamorphic enhancement. It’s not much, but it’s something.
I expect that the majority of people reading this blog post will probably have no idea what I’m babbling on about. First things first, let me direct you to my 2.35:1 Constant Image Height Tutorial. The CIH movement is admittedly a niche within the home theater community, but those of us who do it are passionate about it.
One limitation of 2.35:1 CIH projection is that “scope” movies available in high definition (including Blu-ray) are encoded in letterbox format with black bars eating up a chunk of the available resolution. Since a Blu-ray frame is 1920×1080 pixels, only approximately 1920×815 of those pixels are being used for the active picture content on a 2.35:1 movie. The rest are wasted on the black bars.
To project this onto a 2.35:1 screen, viewers have two options. With the Zoom Method, the letterbox bars are simply allowed to spill off the top and bottom of the screen while the active movie content is zoomed to fill the screen. Alternately (and more expensively), the anamorphic lens method requires that the picture be scaled to vertically stretch the image. This cuts off the letterbox bars, but leaves you with a geometrically distorted picture.
An anamorphic lens will then stretch the image horizontally to restore proper geometry.
The anamorphic lens method has the advantage of using the entire 1920×1080 resolution of the display. However, the extra pixels are interpolated, not real picture content. Unfortunately, the Blu-ray format was not designed with anamorphic enhancement in mind (as you’ll see on DVD with 16:9 enhancement). The creators of the Blu-ray format did not take the needs of Constant Image Height into consideration. Blu-ray pixels are square, and the letterbox bars are baked into the image.
Technically, there’s nothing to prevent a content owner from transferring a movie (or, in this case, a movie trailer) with a 21:9 stretch. When played back on a standard 16:9 HD screen, the image would appear distorted. But when played back with proper CIH gear, the proper picture geometry would be restored. The main reason this hasn’t been done is that Blu-ray players do not have the ability to downconvert a 21:9 anamorphic picture to standard 16:9 letterbox (like DVD players can downconvert anamorphic 16:9 DVDs for playback on older 4:3 TVs).
For whatever reason, a copy of the ‘Transformers: Dark of the Moon’ teaser trailer was transferred in 21:9 format, and can be viewed in the Trailers section of VUDU. There is no downconversion option. Either you can watch this on a 16:9 screen where it will look stretched, or you can watch it on a 2.35:1 screen with anamorphic lens, where it will look correct.
There’s not much to this. It’s just the movie’s two-minute teaser trailer, the one where the astronauts investigate the spaceship on the moon. Honestly, it’s not all that exciting. In fact, the trailer appears to be 720p resolution and has some severe color banding artifacts (and the audio is only Dolby Digital stereo). This isn’t going to be a flawless home theater demo. But it’s an interesting development all the same.
Skip
I don’t get this post: Vudu doesn’t say anything about the supposed enhacement, so I assume it’s a simple mistake not worthy of an entire article; I’ve watched 16:9 TV shows mistakenly squashed into 4:3 and never made much of it.
Josh Zyber
AuthorEven if it wasn’t intentional, some people can take advantage of it nonetheless.
I felt that this was worth a post to explain the concept of 21:9 enhancement, if nothing else.
Drew
I completely agree. This was clearly a simple mistake, and certainly not worthy of a mention, let alone an entire article.
The video quality is crap. This Transformers trailer on Vudu was akin to watching a 16:9 trailer on a standard definition channel. They both look equally awful.
Josh Zyber
AuthorIf you’re referring to the image stretch when you say that it looks like a 16:9 trailer on an SD channel, as I explained in the post, the picture geometry will only look correct when viewed with an anamorphic lens on a 2.35:1 screen.
Other than the banding artifacts, this is clearly high definition video.
This may not interest you. I fully acknowledge that CIH is a niche within the home theater hobby. However, I’ve already received at least one email asking for more info on the trailer based on this post.
Drew
I’m not referring to the image stretch. I’m referring to the video quality. It’s 720P resolution, and chalked full of banding and other artifacts.
I viewed it at a friend’s house on a 124″ screen; Projected CIH with an anamorphic lense. The geometry looked fine, but the quality was abysmal. It was clearly nothing more than a mistake. Vudu probably accidentally stretched the trailer to 21:9, in spite of the fact that their intent was to display it at 16:9.
I’m not a fan of CIH projection. Even using an anamorphic lense, I feel that I get much better video quality with my plasma. I witness much deeper blacks, better shadow delineation, and more finely rendered details. Brightness is obviously another major advantage all television owner’s have. The only advantage to projection that I can see is a bigger screen. However, I know a lot of people that don’t use a screen much bigger than my 65″.
The botton line is, this simply wasn’t worth mentioning. It definitely didn’t deserve it’s own post.
Josh Zyber
AuthorThe banding and other artifacts are a problem with many of the trailers VUDU puts up. The trailers don’t receive the same bit rate or care as actual movie rentals (especially not the HDX rentals). These artifacts have nothing to do with the stretch, but are just coincidental.
It sounds to me like your other complaints aren’t with CIH projection, but with projectors in general. Which just tells me that you’ve been looking at a crappy projector and need to see a better one. 🙂
Drew
I left one thing out.
The title of your post implies that this trailer was given a 21:9 enhancement. This is obviously not the case. The 21:9 was merely a mistake. It did nothing but make the image look worse. Even viewed via CIH projection, it was easy to tell that this was no enhancement. It was nothing more than a Vudu mistake.
Drew
I’ll concede that. My complaints really aren’t with CIH projection. They are more about projection in general. I can certainly see how CIH and anamorphic lenses do improve the dynamic of using a projector for your home theater, but there’s still a lot left to be desired.
I haven’t been viewing crappy projectors. My friend owns a brand new top-end Sony 3D projector. He also just bought a brand new anamorphic lense for it.
I’ll be interested in a projector for my home theater when they are capable of giving me the same quality image I get from my plasma, only on a much larger screen. Essentially, I feel like I would need a legitimate professional movie theater projector in the home to satisfy my requirements.
Josh Zyber
AuthorThere are countless variables to look at here. Is your friend’s projector calibrated? What type of screen (if any) is he projecting onto? Is the room light controlled?
Properly implemented, a good projector will easily rival the picture quality of a plasma at much larger screen sizes.
And you wouldn’t want an actual theatrical projector in your home. They have terrible contrast, and the lamp power would probably burn your eyes out at a home theater screen size.
Eric Hulen
I found it interesting Josh. Very cool news even though I don’t have a CIH projector.
That’s the neat thing about these online movie rental stores. They can easily change and update there content for different formats and not be stuck like Blu-ray is with a spec. Now I wish Vudu would offer more 3D movies.