720p VS 1080i

[rando]

I do weddings mostly and I have the GY-HD100s which are 720p, is the difference between 720p and 1080i that big? and should I just edit in 720p or should I use ProCoder to upconvert the 720p footage to 1080i?

[Rusty]

If your final destination is DVD, 720p is really easy to work with!

[rando]

yes its DVD, im just wondering if my brides would see the difference between 720p and 1080i. Im not sure I could tell the difference. I saw a seminar on HDV a few years ago and the person giving the seminar said you wouldnt see much of a difference until you exceded a 42" screen.

[Bassman]

Are you sure you mean 1080i? 1080p would be upconverting the footage.

1080i & 720p are essentially the same, just a different way to handle the fields/frames.

[STORMDAVE]

1080i/p has higher resolution than 720p.

1080i/p can be:
1920x1080 (Full HD)
1440x1080 (HDV)
1280x1080 (DVCPROHD)

720p can be:
1280x720 (HDV and HD variants)
960x720 (DVCPROHD)

720p is mostly used for progressive footage, such as sports at 60p (for slow mo as well). It is always progressive.

1080p is slowly going to be the superior format (acquisition wise), but it is much harder to handle than 720p for cameras and computers...

Most of the lower res HDTV's out there (1366x768) are 720p, but they support 1080i (interlaced x1080 resolution) so I think there's a confusion between that and what 1080i means...it's just an interlaced version of 1080.

[rando]

Well so 1080 i/p is a higher quality then 720p, is there a large difference? if there is should I upscale the footage myself via PC or export to 1080 with Edius or should I let the peoples TVs do it?

[cuervo]

I would disagree with the statement that 1080i is higher quality than 720p. Given that both formats have the same data rate, I would suggest that 720p has more captured bits than 1080i. For example, consider 24fps. At 720p you're talking 720x1280x24=22.1 Mpixels/sec. At 1080i you're talking 1440x1080x24=37.3Mpixels/sec. Assuming a max data acquisition rate of 25MB/sec and 24 bits/pixel(3 RGB channels x8 bits/channel), the data acquisition rate for 720p is .38 MB/sec. For 1080i, the data acquisition rate is .22 MB/sec.

Where does the user realize the increased data capture rate? I suggest it is in the image quality.

Have I missed something in this calc?

[STORMDAVE]

Uhm you can't disagree with the fact that 1080i has more res. than 720p :)
Even under HDV, 1080i has higher res than 720p.

So in other words, a Sony FX1 has higher resolution than a JVC HD100 720p camcorder.

HDV 1080i is 25mbps...HDV 720p is 19mbps.

[Bassman]

I think you also have to factor in that 1080i uses half of the frame resolution per field.

So this does not translate into the full 1080 lines being used.

I would also disagree that 1080i can be lumped in with "full HD", which has been come to be known as 1080p in the T.V. retail world.

In the end, this is kind of a numbers only game because I don't think resolution wise there is much of any visual difference between 720p & 1080i.

The two formats do have a different visual feel though.

And in my opinion, nothing to upgrade up or down to.

[rando]

In the end, this is kind of a numbers only game because I don't think resolution wise there is much of any visual difference between 720p & 1080i

Now thats the answer I was looking for:)

[STORMDAVE]

I think you also have to factor in that 1080i uses half of the frame resolution per field.

So this does not translate into the full 1080 lines being used.

I would also disagree that 1080i can be lumped in with "full HD", which has been come to be known as 1080p in the T.V. retail world.

In the end, this is kind of a numbers only game because I don't think resolution wise there is much of any visual difference between 720p & 1080i.

The two formats do have a different visual feel though.

And in my opinion, nothing to upgrade up or down to.

I wasn't lumping 1080i into Full HD, only 1080p.

I think you're confusing fields here...Interlaced is still used to this day because it has become the standard in the TV world. Progressive is the standard in the film world.

All of this depends on the camera's native resolution. If it is a true 1080p sensor, it will also do 720p.

I was working with full 1920x1080 interlaced footage in EDIUS, and let me tell you, the 720p footage looks inferior (obviously because of the resolution) from the same camera.

You're better off reading this.

And Randy, work in a 720p project and go to DVD from the HD project...if you ever need to do Blu-ray in the future with the same footage, you will just have to do a 720p project.

[Blast1]

Interlaced is still used to this day because it has become the standard in the TV world

Interlaced is used because of broadcast bandwidth problems, a broadcast transport stream channel is speced to handle two 1080i or four 720p, a 1080i two line overlap field has a vertical res close to 720p because of the 70% factor of the overlapping fields, the horiz res on either exceeds the visual acuity of the eye which is about 800 tvl, the 1080i is good for sports broadcast because it handles motion better than progressive scan because of the interlace and extra bandwidth, 720p is more economical because twice the data per channel can be handled, when you start talking about other methods of distribution the bandwidth goes out the window.

[STORMDAVE]

But 1080i still has more res than 720p...That's my whole point. :)

[fukly]

i read from others forum...they said progressive is the best for sport..coz they do alot of slowmo..to preview..n i do know how bad interlace in slowmo, specially when u use10% speed..so which one is right?

[STORMDAVE]

I know for sure that ESPN HD is 720p...Don't know about the rest.