720p vs 1080i

[zoobie]

Someone care to tell me why 720p is a higher resolution than 1080i?
That's what's being mentioned at some forums around the web.
I just got a new Sony HC1 but can't signup for some reason at dvinfo.net
Thinking of selling it to get the new (April release) Canon HV-20 which, thru the pulldown, converts 1080i to p
Linkage?
Thanks

[killerhex]

720p_versus_1080i

http://en.wikipedia.org/wiki/720p#720p_versus_1080i

[oldandinthe way]

Because 720 is larger than 540. 1080i is interlaced 540 lines.

[deadrats]

Someone care to tell me why 720p is a higher resolution than 1080i?
That's what's being mentioned at some forums around the web.
I just got a new Sony HC1 but can't signup for some reason at dvinfo.net
Thinking of selling it to get the new (April release) Canon HV-20 which, thru the pulldown, converts 1080i to p
Linkage?
Thanks

it's not. by definition, 720p is comprised of full frames, each of which has dimensions of 1280 pixels horizontal by 720 pixels vertical, 1080i is comprised of 2 fields (to give the equivalant of 1 frame) and each 2 fields combo has dimensions of 1920 pixels horizontal by 1080 pixels vertical.

what happens is some people seem to think that 1080i is equal to 540p and thus conclude that 720p is a higher resolution that 1080i, but that's just not true:

http://en.wikipedia.org/wiki/1080i

http://en.wikipedia.org/wiki/720p

[RLT69]

what happens is some people seem to think that 1080i is equal to 540p and thus conclude that 720p is a higher resolution that 1080i, but that's just not true:

If only that were true.

From the link you posted:

"The main tradeoff between the two is that 1080i may show more detail than 720p for a stationary shot of a subject at the expense of a lower effective refresh rate and the introduction of interlace artifacts during motion. 720p is used by ABC and ESPN because the smoother image is desirable for fast-action sports telecasts. Fox Broadcasting Company uses the tagline "the nation's finest high-definition standard" in advertising its 720p programming."

The issue here is INTERLACE versus PROGRESSIVE. 1080i is interlaced and has all the flaws of interlaced video. 720p is progressive and has all the advantages of progressive video. Bottom line true HD is progressive scan pure and simple. 1080i can give you more lines of resolution than 720p however because it's interlaced you will have artifacts in certain video scenes, such as action scenes.

Bottom line 1080i is a band-aid measure until 1080p becomes common place.

[manono]

If only that were true.

What deadrats said is true, and doesn't contradict what you said later about 1080i being interlaced. Interlaced vs progressive is a different issue entirely. The original question was about the resolutions of the 2 formats. I don't see that anything you said or quoted contradicts anything deadrats said. On the contrary, you confirm what he said.

[zoobie]

Well, I'm not going to be able to wait for 1080p to become the standard as my hi8 cam died. I'm shooting jugglers and acrobats outdoors on a tripod. Trying to decide if this is high-action and if I should switch cams.

I guess 720p is good enuf for ABC and ESPN.

Thx all...I need access to that dvinfo.net...ugh. My HC1 ships today.

[edDV]

Where are you reading that the Canon HC20 does 720p? As far as I can tell the HC20 is normal 1440x1080i HDV, same as the HC1. The Sony HC1 probably has better performance but we won't know that until the HC20 is tested.

For action shots where stop action is important, 720p is desirable but true 720p models are in a much higher price range (e.g. Canon XHA1).

Actual picture detail for these single sensor consumer HDV cameras will be far below 1440x1080 whether 1080i or 720p. The optics, sensors and processing are the limiting factor. For example, the higher end JVC GY-HD100 720p camcorder needs a $12,000 lens option to come close to broadcast 720p quality.

[zoobie]

I guess I'll have to go for the psudo 720p prosumer then. I could Visa that huge cam but my wife would kill me. Instead, I'll keep researching and maybe end up taking her to Hawaii this year...with my new cam of course...and stay alive.

Thx

PS - I'm not sure that new Canon @ 1080p24 could handle some of my high action shots but I see high end pro stuff would.

[edDV]

I guess I'll have to go for the psudo 720p prosumer then. I could Visa that huge cam but my wife would kill me. Instead, I'll keep researching and maybe end up taking her to Hawaii this year...with my new cam of course...and stay alive.

Thx

PS - I'm not sure that new Canon @ 1080p24 could handle some of my high action shots but I see high end pro stuff would.

The HD20 is basically a HDV 1440x1080i camcorder. The "24P" mode is highly controversial until tested. We shall see. But 24p is the opposite of what you want for sports action. Broadcast 720p uses 59.94 frames per second for sports action motion detail. 24 fps would be very jerky for motion but all the film school tricks could be used.

1080i has all the interlace issues on progressive screens but should play well with 59.94 fields per second. 30F would be a good compromise.