Last April, Mark Henninger compared various HD varieties of Interstellar. How does the UHD streaming version from UltraFlix stack up?
Interstellar provides a perfect platform for performing picture quality comparisons. Director Christopher Nolan shot the movie with Imax 70mm film, which is a super-high-resolution format—promotional material touted it as possessing "almost ten times the resolution of standard projection formats."
In my Interstellar: Blu-ray vs. iTunes vs. Vudu vs. Amazon
piece, I concluded by asking, "Will UHD/4K online delivery from a cloud-based service match or beat Blu-ray video and audio quality?" When I recently reviewed the Vizio M65 UHDTV
, I had the opportunity to watch Interstellar using UltraFlix, a service that offers streaming UHD/4K movies.
UltraFlix does not stream from a PC, so I could not take screenshots, as I did in the 1080p comparison. Instead, I used a 64" Samsung F8500 plasma TV and a 65" Panasonic CX850 FALD-LCD TV to watch the various 1080p versions concurrently with the UltraFlix version. Whereas the F8500 provided a native 1080p rendition of the 1080p formats, the CX850 showed me what the upscaled 1080p streams looks like when playing on a high-end UHDTV.
I had planned to compare the sound quality of the UHD stream as well as the picture quality, but I was only able to get stereo sound from UltraFlix on the Vizio M65. 5.1 surround works with Audio Return Channel (ARC) via HDMI when streaming from other services, so that was a disappointment. I read that UltraFlix does offer 5.1 surround, so I hope the issue will be resolved in the future—without good sound, UHD/4K isn't going to succeed.
While I lamented the lack of 5.1 surround sound, the picture quality provided by the UltraFlix stream was another story—it was great. After signing up for the service, I rented Interstellar for 10 bucks. When I launched the app on the Vizio M65, it measured the available bandwidth, which clocked in at 55-60 Mbps with Wi-Fi. I switched the Vizio to Ethernet and throughput jumped to over 100 Mbps.
The moment I saw the first few frames of Interstellar in streaming 2160p, I realized it made the 1080p streams from Amazon, iTunes, and Vudu look inferior, even outdated. Interstellar on Blu-ray fared quite a bit better versus the UHD stream, but there was no question the UltraFlix stream showed more detail.
According to a recent press release, "UltraFlix also offers users with 100 Mbps connections streaming quality identical to the new Ultra HD Blu-ray specifications—another innovation first by NanoTech." I don't know if that's the speed I experienced when I streamed—I can't measure bandwidth directly while watching content—but it's nice to know streaming at that quality level is possible. For what it's worth, I could not see a difference in image quality between using Wi-Fi or Ethernet to stream Interstellar.
Streaming formats tend to struggle the most on dark shadows. Often, it is the shadowy scenes that trip up compression algorithms. With movies that take place in outer space, I sometimes see macro-blocking and posterization show up in nebulas, galaxies and other complex, wispy textures. Whenever such artifacts manifest, it takes viewers out of the movie instantly—suspension of disbelief is broken. However, with Interstellar on UltraFlix, I stayed in the movie the whole time, despite the 2-channel audio. The stream looked pristine, even in the deepest shadows, while action scenes rendered with great detail—the 1080p streams would always become blurry when the action picked up. When I scrutinized the UHD image close up, I was rewarded with nothing less than accurately rendered film grain—that's amazing!
The benefit of having four times as many pixels was not always obvious; it varied depending on the content of the scene. Many scenes that take place on Earth—especially static shots with dialog—looked practically identical on Blu-ray and via UltraFlix. Nevertheless, the UltraFlix version tended to look just a bit better if you scrutinized it—details like hair and fabric had more detail and texture in UHK/4K.
Some of most impressive improvements afforded by UHD/4K involved the amount of detail seen in outer-space scenes. I especially appreciated the improved rendering of the surface textures on the Ranger (the spaceship in the movie), planet surfaces, and all the trippy details in the scenes near a black hole.
The benefits of UHD resolution are invisible if you sit too far from the screen. I found I had to sit eight feet or closer to the M65 in order to notice the extra detail. At my typical viewing distance of seven feet, the difference in detail rendition between streaming HD formats (Vudu HDX, Amazon HD, iTunes HD) and Blu-ray were of the same magnitude as the difference between Blu-ray and the UltraFlix stream—a small but readily apparent improvement.
Sitting just one foot closer than I typically do increased the visible difference in resolution between UltraFlix and the 1080p formats, indicating that a larger screen would offer an additional benefit in terms of how much resolution reaches the retina when streaming UHD/4K content.
While UltraFlix streaming does beat Blu-ray image quality, the difference was subtle from seven feet away. However, the difference between 1080p and UHD streaming was quite a bit more noticeable. I had to step back to about ten feet from the screen before I stopped seeing more detail in the UHD version versus the HD streams. Between the absence of visible compression artifacts and the obvious step up in detail rendition, there's no question that UHD streaming on UltraFlix looks better.
As long as UHD streams and downloads come with audio that matches the visuals in fidelity, they are a viable option for viewing in home theaters and on large TVs. The real question is whether the next generation of physical media—Ultra HD Blu-ray—will offer yet another significant step up in image quality. I look forward to writing my first comparison of UHD/4K physical media versus online delivery. HD streaming has improved immensely since Netflix popularized it five years ago, but it is far from perfect. Now, high-quality UHD streaming is here, and it looks quite amazing to my eyes. What are your thoughts? Have you seen Interstellar via UltraFlix?
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