Interstellar: Blu-ray vs. iTunes vs. Vudu vs. Amazon

It’s been over two years since I posted my first comparison of Blu-ray versus online delivery. During that time, I’ve witnessed a noticeable improvement in quality from the cloud-based options. Still, Blu-ray has beaten online delivery in every comparison I’ve performed.

With Vudu officially rolling out UHD streaming this year—including Dolby Vision (HDR) and Dolby Atmos (immersive sound)—online delivery might finally surpass Blu-ray quality. But until then, 1080p, standard dynamic range, and 5.1/7.1 audio are the best available specs from physical media or streaming sources.

My latest comparison of Blu-ray and streaming involves Interstellar, a spectacularly beautiful movie, much of which was shot on 70mm Imax film. Thanks to the incredible resolution that Imax cameras capture, it contains much more visual detail than any 1080p video format can convey. Of course, all that resolution must be downscaled to 1080p for Blu-rayand streaming.

The Blu-ray release of Interstellar came with an interesting souvenir—a film cell from a 70mm film print. It’s the first time I’ve been able to compare film-based Imax 70mm to Blu-ray and online-delivery formats. There’s no comparison—even with the generational loss incurred by photographically scanning a film print and downscaling it to 1920 pixels wide, there’s much more detail in it compared to Blu-ray—see for yourself:


I downsampled a photographic scan of the 70mm film print to match the dimensions of the unresized, cropped Blu-rayscreenshot.

In this comparison, I photographed the 70mm film frame included with the Blu-ray using a 20-megapixel camera and downscaled it to match the dimensions of an unresized Blu-ray screenshot of the same image. I saved both as PNG files for maximum fidelity and cropped them so they weren’t too large for the AVS Forum image-hosting system. As you see, the photo of the film frame exhibits more detail than the Blu-ray screen shot.


Here is the original 70mm film cell I photographed.

With Interstellar, the best-performing cloud-based format was Vudu HDX, followed by iTunes HD and trailed by AmazonHD. The gap between online-delivery formats and Blu-ray was moderately obvious—Blu-ray retained more detail as well as film grain. Furthermore, the Blu-ray preserves the changing aspect ratio of the movie; the online formats cropped the movie to 2.40:1 from beginning to end. Unfortunately I was not able to receive Amazon’s highest-bandwidth stream on my PC and the screenshots show it—Amazon HD consistently looked softer than the other cloud-based formats.

Being a space movie, Interstellar contains many scenes with deep shadows and black backgrounds. Contouring and blocking artifacts often manifest in dark regions, and online-delivery formats are more likely to suffer from these compression-related artifacts than Blu-ray. This was certainly true here, even with Vudu HDX.

When it comes to sound, Blu-ray outperforms online delivery by a noticeable margin. With uncompressed 24/96 audio to work with, Interstellar on Blu-ray is an impressive-sounding movie. If your subs are up to the task, it’ll rattle you to the bone.

I thought the sound quality of Vudu HDX was the best of the online delivery formats. HDX uses Dolby Digital+, and it managed to retain a measure of the dynamics found in the Blu-ray’s DTS-HD Master Audio 5.1 soundtrack, but it was not as immersive or impactful.

iTunes and Amazon sounded identical. I sensed moderate a loss of clarity compared to Blu-ray. Bass seemed to suffer the most; it just didn’t have the same gripping and guttural physicality of the Blu-ray version.

Will UHD/4K online delivery from a cloud-based service match or beat Blu-ray video and audio quality? I’m dying to find out. On top of that, the next-generation Ultra HD Blu-ray is due this fall. I look forward to the first comparison that includes such content. For now, check out the following screenshot comparisons to see how Blu-ray picture quality continues to beat 1080p cloud-based formats.

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The following comparison images are best viewed full-size at 1920×1080 pixels. Please click the provided links to see the original images.


Blu-ray is considerably sharper than the online-delivery formats.http://www.avsforum.com/forum/vbimgh…mg&imgid=10617


With Blu-ray, you see more streaking stars and the streaks vary in color—unlike the online-delivery formats.http://www.avsforum.com/forum/vbimgh…mg&imgid=10625


Look at how Blu-ray renders the rays of light. http://www.avsforum.com/forum/vbimgh…mg&imgid=10657


Amazon HD lags behind the rest in this screenshot. http://www.avsforum.com/forum/vbimgh…mg&imgid=10649


Compression artifacts show up in the Amazon and Vudu versions.http://www.avsforum.com/forum/vbimgh…mg&imgid=10641


Compare the textures on the spacecraft’s hull. http://www.avsforum.com/forum/vbimgh…mg&imgid=10633

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TEST SYSTEM

Sources

DIY HTCP (Windows 8.1)
Oppo BDP-103 Blu-ray player

Display

Samsung PN64F8500 plasma HDTV

Audio

Pioneer SC-85 AVR
Crestron ProAMP 7×250 power amp
GoldenEar 5.1.4 speaker system