Seeing is believing, while numbers can lie. What you see is what you get. A month ago, I advised readers to buy a new TV, since current 4K models look so much better than TVs from a decade ago, while costing less. A reader disputed my rosy recommendation:
"Having just read your article in the Gazette, I thought it might be time to move on from my 10-year-old 46-inch Sony 1080p TV. But since 99 percent of my viewing consists of watching content delivered by Comcast, I was wondering how much of an improvement in picture quality a 4K TV would provide. Alas, the Google machine has made me reconsider retiring the Sony. At forums.xfinity.com, there is a very long thread under the topic 'poor picture quality since upgrading to a 4K TV.' The upshot seems to be that Comcast's compression of the source signals that they receive destroys too much data for reasonable upscaling to occur on a 4K TV. The picture quality seems to be worse than it was on the older generation TVs of those who posted. Until I hear more positive responses about watching content from Comcast, I will be keeping my Sony."
I connected this reader with experts at Comcast, but he declined to pursue the matter. Jack Siegel, vice president of communications, Comcast greater Chicago region, responded to me:
"We receive content from programmers in various formats. All content we receive is transcoded into the MPEG4 format and distributed to customers. MPEG4 delivers a higher quality picture. Variations in the customer's TV's capabilities and settings can have an impact on the quality of the picture. Anyone who wants to check out Xfinity TV or ask questions is welcome to visit the Xfinity Store at 2000 N. Neil St. in Champaign."
Never believe everything you read in online threads. Many posters understand less than you do. Some people denigrate Comcast no matter what.
All program providers, cable and satellite, employ some degree of compression. Otherwise they could not offer the wide diversity of channels people demand. The greater the compression, the lower the quality of the picture, all things being equal. Providers compress each channel differently. Thus, at a given resolution, the Home Shopping Channel will probably look much worse than HBO. Providers usually compress sports the least.
Viewing programming via the internet rather than cable offers greater control over picture quality. Some providers, such as Netflix, offer different levels of resolution. The amount of compression and resolution depends upon your internet bandwidth, that is, the speed of your connection. My 75 mbps connection delivers stunning video from Amazon Prime video. It's full 1080p, flawlessly upconverted to 4K on my LG TV.
Because LCD screens should display video in their native resolution, all 4K TVs upconvert to 4K. The less upconversion that's necessary, the better.
Generally a 1080p video will look far superior to a 720p video. However, resolution is separate from compression. The tricky part, to which our reader refers in his letter, is that too much compression muddies the picture and the upconversion process.
Some of this depends on your specific TV, as not all brands use the same algorithm to upconvert the picture. Where the reader is misinformed is that not all cable supplied video suffers excessive compression. If he remains concerned by that, then the solution is a high-speed internet connection and a Roku stick or similar device.
The cost between subscribing on cable or from the internet comes out about the same, or perhaps the internet slightly is less expensive.
Every 4K TV comes with an entire menu of settings to optimize source to picture. Misadjusting just one of those settings can noticeably reduce picture quality.
This is why Siegel from Comcast recommends visiting their local store to see for yourself. You may be very pleasantly surprised how good your favorite shows look on a 4K TV.
Rich Warren, who lives in the Champaign area, is a longtime reviewer of consumer electronics. Email him at firstname.lastname@example.org.