Mark Henninger discusses his recent experience with a UHDTV and UHD/4K content, including videos, games, web browsing, and still photos.-------What good is a UHD/4K TV without native UHD/4K content? Scott Wilkinson's recent article about whether you need native UHD/4K content got me thinking about my recent experience with a Panasonic TC-65AX800U UHDTV that I am in the process of reviewing. Prior to that TV, my experience with UHD/4K was limited to trade shows, PR events , store showrooms, and TV-testing labs. Now, I've lived with one for about a month and a half.I'm near the end of the review process for the AX800U, which served as my primary display on my PC for the past five weeks. Fortunately, my last video-card upgrade included UHD/4K capability and a DisplayPort output, which opened up a veritable cornucopia of 4K-compatible content via the Internet.Unlike Sony and Samsung, Panasonic doesn't have a dedicated hardware solution for UHD/4K content delivery. The AX800U can't stream UHD/4K content from Netflix—no House of Cards or Breaking Bad for me. On the other hand, it does include a DisplayPort input, which is capable of accepting 8-bit 2160p at 60 frames per second with full 4:4:4 color—in other words, it's ideal for use with a PC.When it comes to video-game graphics, 2160p resolution is a significant improvement over 1080p. During gaming sessions, I sat about five feet away from the AX800U's 65-inch screen, close enough to appreciate the improvement in image quality afforded by six million additional pixels. I especially appreciated the decrease in stair-step artifacts, which seem to plague 1080p games, no matter how high the antialiasing setting. Without a doubt, on a properly equipped PC, UHD/4K increases the visual realism of games that support 2160p resolution with an added depth to the imagery. For games that overtaxed my video card at 2160p, I used 2560x1440 resolution and achieved 40-60 fps.One of my favorite uses for UHD/4K is viewing still photos. For over a decade, I've shot various DSLRs that exceed UHD/4K resolution. At this point, I have many thousands of images that I can finally see in all their glory without having to make a poster-size print. Unlike movie watching, it's perfectly normal to closely approach the screen to marvel at micro details and fine textures when looking at a still photo. Thanks to UHD/4K TVs, the slideshow is back! There is no denying the impact of the extra resolution when viewing photos—it's a lot more obvious than with compressed video. There's a near limitless supply of high-resolution photos out there that meet or exceed UHD/4K resolution. As long as you appreciate visual art and photography, there is plenty of great content that takes full advantage of UHD/4K resolution—it's just not video.For UHD/4K video, I relied on YouTube's streaming offerings. Unfortunately, there is no inexpensive, ubiquitous device—like a Roku, Apple TV, or Chromecast— that's capable of delivering UHD/4K content to any brand of UHDTV. I had to settle for highly compressed streaming content, mostly from YouTube; at least I was able to sample some previews of movies I've already seen on Blu-ray, like Man of Steel. I can't say I spent much time on YouTube, and the 2160p streams also looked great on my 1080p TVs thanks to the fact that YouTube downscales its videos. Whenever there was fast motion, the plasma rendered more detail; during relatively static scenes, the AX800U looked sharper. I suspect streaming UHD/4K video requires more bandwidth before it can beat Blu-ray's pristine 1080p in terms of overall quality. One thing is for sure, YouTube's 1080p streams are nowhere near the quality of its 2160p streams, whether viewed in native 2160p, or downscaled to 1080p.Aside from video games and still photos, one of my favorite uses for UHD/4K is browsing the Internet. I love how text renders smoothly, as it does on a high pixel-density tablet or smartphone—the effect that Apple calls Retina. It's easy on the eyes, and the look reminds me of print instead of digital. I never thought that I'd prefer to read The New York Times using a TV, but UHD/4K made it so.For a different sort of UHD/4K diversion, I'd like to give a shout-out to the Aeon visualizer from Soundspectrum. When I listen to music and display Aeon full-screen, the resulting UHD/4K graphics look stunning and provide the perfect accompaniment to my favorite albums. Aeon creates psychedelic abstractions that pulse to the music, using the computer's video card to render its graphics. I've enjoyed many hours relaxing to Aeon; it's a worthwhile addition to any PC, that happens to look very impressive when running at 3840x2160 resolution.Along with the AX800U, Panasonic loaned me a UHD/4K video camera, the HX-A500 , which provided me with a source of UHD/4K video that was not as compressed as what I found on YouTube. That footage turned out to be some of the best I viewed, and it cemented my belief that in its current manifestation, UHD/4K has a lot to offer anyone who creates their own content. If you have a camera or camcorder capable of capturing UHD/4K video, it makes sense to have a TV capable of displaying the footage at its native resolution.Upscaled 1080p is the greatest disappointment in my UHD/4K experience; I don't understand the hype surrounding it. If there is any noticeable improvement in image quality over 1080p, it appears to come from the elimination of any visible pixel grid at optimum 1080p viewing distances. It did not improve the content itself. When watching reference-quality Blu-ray, my Samsung F8500 1080p plasma looked sharper than the UHDTV sitting right next to it, partly due to the superior motion rendering offered by plasma. Also, in a dark room, the plasma's superior contrast gave it the edge in terms of image quality and overall realism versus the LCD-based AX800U. My conclusion is that UHD/4K TVs desperately need more cinematic content if they are going to appeal to mainstream TV buyers.I truly look forward to the next step in UHD/4K's evolution—namely, an expansion of the movie catalog and the end of proprietary delivery mechanisms. With DirecTV's recent announcement that it will stream UHD/4K on-demand this year , and Comcast hot on its heels with plans for a 4K app, that day looks like it will arrive sooner than later. I'm glad I got this first taste of UHD/4K out of the way; now I want to see what the rest of this year's UHDTV offerings look like, especially LG's forthcoming OLEDs.So, what did I make of my initial UHD/4K experience? I'm hooked on the added resolution, no doubt about it. However, I'm not ready to make a UHDTV my primary display for watching movies. That honor belongs to my 1080p F8500 plasma, which offers an exceptional image when paired with Blu-ray or high-quality 1080p streams. Even so, I'm already thinking about upgrading my 1080p Vizio M3D550KD to a UHDTV after Panasonic picks up the AX800U. I know I'll miss having it on my PC. After all, I'm using the AX800U in 2160p mode to write this article. The on-screen text looks fantastic!If you have a UHD/4K TV, let me know about your favorite forms of 4K content.