According to a press release issued this morning, Amazon has begun offering some limited amount of its streaming content in 4K resolution—specifically, the 4K UltraHD standard resolution of 3840×2160. The majority of the 4K content for now appears to be Amazon original series like Alpha House and Transparent, supplemented with a limited number of studio TV series (Orphan Black is mentioned specifically).

Additionally, Amazon will be offering a selection of 4K movies from Sony Pictures Entertainment for free streaming to Prime members. Four movies are listed as streamable in 4K: Crouching Tiger, Hidden Dragon; Funny Girl; Hitch; and Philadelphia. Amazon will be using HEVC (High Efficiency Video Encoding) for video compression.

Although streaming 4K content will be limited to Prime subscribers, Amazon isn’t keeping all the 4K love only for Prime—all Amazon customers will be able to purchase several additional Sony Pictures films that won't be available for instant streaming. The list in the press release is all over the map with respect to age and type—1998’s The Mask of Zorro and 2012’s The Amazing Spider-Man reboot are listed, as are 2008’s Hancock and 2000’s The Patriot. So far, movies from studios other than Sony Pictures aren’t available, but the press release is confident that more 4K content will be available in 2015.

There are three major caveats to Amazon’s 4K services. First, the 4K content will only be available within the US. Second, the bandwidth requirements are as yet unknown, but given that a 4k UltraHD stream nominally contains four times as much image data as a 1080p stream, interruption-free 4K streaming is something that a lot of people will have issues with (either because of their own connection or because of chicanery like this).

The final caveat is that in order to watch any of Amazon's 4K programming, you’ll need to use an approved 4K "smart TV" from LG, Sony, or Samsung. It appears that computers with 4K-capable monitors need not apply—Amazon has a handy list of approved 4K TVs that range in price from about $900 all the way up past $25,000.