Almost two weeks after Amazon Prime Video's new ad-free subscription plans were unveiled, users are already beginning to see additional differences between the more expensive options and the ad-supported plans: the absence of Dolby Vision and Dolby Atmos

These changes in streaming quality were first spotted by German news site 4Kfilme

Various tests were conducted on a wide range of the best TVs, including models from Sony, LG, TCL, and Samsung Note that Samsung TVs do not support Dolby Vision HDR content, but the company and Google are working on their own iteration of this technology standard

Other audio and visual technologies such as 51 surround sound, 4K resolution, HDR10 and HDR10+ still exist, but the loss of both Dolby Vision and Dolby Atmos is a considerable change

Amazon Prime Video's new, more expensive ad-free tier rolled out first to customers in the US on January 29, then to those in the UK, Germany, and Canada on February 6 The price increase adds $299/£299 to the monthly fee to cut out annoying ads that enter in the middle of Prime movies and shows

After the upgrade, Prime Video customers will again have access to both Dolby Vision and Dolby Atmos Amazon itself has confirmed the technical downgrade for ad tier subscribers to Forbes magazine, assuring users that it is not a technical error

Confusingly, users with a basic Prime Video subscription will continue to have access to both HDR10 and HDR10+ alternative HDR formats and 51 surround sound It is unclear if these will later be pushed up to premium plans, but at this point it appears that they will remain on Prime's basic plan

Amazon did not mention anything about these changes before users discovered them This is another example of Amazon pushing for better ways to monetize However, with alternatives to both Dolby Vision and Dolby Atmos coming in the near future, there will be those who do not want or need the upgrade in the first place

Called Project Caviar, Samsung and Google have partnered to design their own versions of Dolby Vision and Dolby Atmos It is intended to mirror the possibilities offered by these two audio and visual technology enhancements, as well as bring additional "functionality beyond what Dolby Atmos and Vision offer," according to the protocol

HDR10+ is part of Project Caviar, which aims to bring royalty-free 3D audio and HDR video formats to a wider audience beyond the excessive foothold that Dolby has with Vision and Atmos

Dolby Atmos, tentatively called Immersive Audio Model and Formats (IAMF), has been in development since 2020 under Samsung and Google In a blog post published late last year, Samsung outlined the many ways in which IAMF will enhance the viewing experience

It is unclear when Samsung TV buyers and prospective users can expect official rollout of IAMF and its broader Project Caviar initiative

For now, it may be best for Amazon Prime Video customers to upgrade to the premium tier if they want the improved video and audio quality of Dolby Vision and Atmos support - especially the best Dolby Atmos soundbars, if you have one