1080i/24p with reduced resolution?

[Jan Crittenden livingston]

Ah ha, I see what your reference is. I do believe that Poynton is referencing Standard Definition Screens as that is where excessive resolution comes to play. In HD it is not the same game. I think of twitter as the temporal difference, and that is what I was thinking of earlier in responding to you as it have seen the excessive resolution on SD systems turn into what I would call aliasing not interfield twitter.

Point it is not the same in HD except the temporal differences.

Hope that helps,

Jan

Jan Crittenden Livingston
Product Manager, DVCPRO, DVCPRO50, AG-DVX100
Panasonic Broadcast & TV Systems

[Graeme Nattress]

HD is just the same though in an interlaced system. It doesn’t matter what resolution – if it’s interlaced, the issue is the same.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Jan Crittenden livingston]

The difference is that in HDTV the monitors are able to resolve the resolution, unlike SD.

Best,

Jan

Jan Crittenden Livingston
Product Manager, DVCPRO, DVCPRO50, AG-DVX100
Panasonic Broadcast & TV Systems

[Graeme Nattress]

It’s not a resolution issue though – it’s an interlace issue. That’s why 1080i has no more vertical resolution than 720p.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Graeme Nattress]

Here’s an EBU paper: https://www.ebu.ch/en/technical/trev/trev_301-editorial.html which talks about interlace twitter in HD formats.

Graeme

– http://www.nattress.com – Film Effects and Standards Conversion for FCP

[Toke]

[Jan Crittenden Livingston] “The difference is that in HDTV the monitors are able to resolve the resolution, unlike SD.”

1080i crt will _not_ handle unfiltered 1080p without “interlace flicker”.
It is excactly the same than 480i crt (ntsc) won’t handle unfiltered 480p without flicker.

Flicker occurs in interlced picture when there’s a detail that has only height of one scan line or one pixel. It gets drawn only every second field (=half frame) and that’s why it blinks 30 times per second (25 Hz in PAL or 1080i50).
It does not matter how many scan lines there is in the picture. Everybody who has used Commodore Amigas or old graphic cards with pc that had interlaced modes will remember this. Same flicker shows with 320i/320p, 640i/640p, 800i/800p and so on.

Jan, if you don’t believe us, ask somybody in tech department at your work or go see any post house that uses those madly expensive sony’s 1080i crt production monitors with 1080p material.

If somebody who has hvx200 and 1080i crt monitor could hook these up to each other and tell if there’s any flicker. If there is flicker, then hvx200’s 1080p is not filtered and it has more vertical resolution than 720p. If there isn’t any flicker then 1080p is (low-pass) filtered and it can’t have better vertical resolution than 720p.

Jan, how much better horisontal resolving power 1080p mode has compared to 720p mode?
Some “official” resolution chart shots would be very clarifying, thank you!

So far we have only some not so professionally produced chart shots which show only a little over 600 lines of horisontal resolution even with 1080p!
Take a look at Zeiss’ web site. They have published very convincing MTF graphs of their digiprimes.
They have nothing to hide, so do Panny has…? (Did I hear somebody saying ccd specs and pixel shift type? …Nooo… 😉

[Gary Adcock]

[toke lahti] “1080i crt will _not_ handle unfiltered 1080p without “interlace flicker”.
It is excactly the same than 480i crt (ntsc) won’t handle unfiltered 480p without flicker.”

Since most 1080i CRTs do not play true 1080p images, if nothing more than because there are only true 1080p 24 in the Dual Link/ 4:4:4 world, not something that either the hvx 200 / or the in camera captures to tape from a non Panavised HDCAM.
The 1080 frame rate I am going to assume you are talking about is the 1080 24PsF that is shot by HDCam’s tape transport system and is played back normally at 48i on most displays.
Due to the spec for delivery to a display of the 1080 24psf format it is regarded as Segmented Frames.

Gary Adcock
Studio37
HD and Film Consultation
Chicago, IL USA

[Toke]

Interlace flicker has nothing to do with frame rate.
All 1080i displays can show 1080p24/25/30 shot material, when it is feeded in 1080i50/60.
That’s what most broadcasters do; broadcasting progressive film footage in 1080i.
Hvx200 records 1080p material in 1080i/24p/30p mode, so it converts the progressive picture to 1080i already because of legacy reasons of dvcprohd tape format.