i purchased a 1080 p high def tv. i am wondering since i have comcast do i have to pay to get hd service. all of the channels say the pic is in 720 p.

720p is technically HD, but that's the lowest HD standard. 1080p (or 1080i) is the next step up (and then, 4K). If it says 720p, then you already have HD I guess. As of a couple years ago broadcasters used either resolution -- depends on the network first, and then the provider (Comcast). I have Fios, and actually am not sure what they broadcast these days. All I know is, I have a 4K TV, and cable doesn't broadcast that except on perhaps a couple dedicated channels for specific events (and even then, you need their latest box). (As opposed to some streaming options that do broadcast on 4K more often -- for instance, most new Netflix series are in 4K).

For smaller screens, resolution doesn't matter as much. But if you have a big screen TV, you'll want a higher resolution. 4K looks incredible! But it's still a novelty in most cases. But in the end, if it looks good to you, that's what's important. If you have $ to burn, when your TV goes, upgrade....

so in other words they don't broadcast in 1080 P yet.

1080p, not so much... that's more reserved for On-Demand and Pay-Per-View. For normal broadcast/cable viewing, it's usually 720p or 1080i (which are also considered HD).

Again, I haven't had Comcast in years, so whether you have to pay for it or not, I have no idea.

But I did find this wiki link that shows what each network (in the USA) broadcasts in, and other details:

https://en.wikipedia.org/wiki/High-definition_television_in_the_United_States

My Samsung adjusted automatic to 1080dpi

Go to your setting using TV remote and search for viewing options, set it manually to 1080 dpi and also use backlit setting if you have it.

Once you have it set , your screen will adjust automatically what the broadcast and provider is sending.

All cable has the 1080dpi quality its up to the broadcast you are watching to have filmed or airing in HD.

i have a hisense television.

kudos and thanks.

TV resolution isn't measured in dpi (dots per inch) per se. Talking about dpi (or more accurately, ppi -- pixels per inch) is more a reflection of the device you're looking at (how large the pixels are -- they'd be huge on a jumbotron (inches per pixels, for instance) vs your smartphone (400+ ppi).... It's confusing for sure..

The letter p in 720p and 1080p stands for "progressive" and the letter i stands for "interlaced"

1080 itself stands for a screen resolution of 1920x1080 (and 720 means 1280x720).

Here's a good explanation:

https://www.youtube.com/watch?v=H_o5h5SK_70