BluRay from EX3-30p ?

[Enrique Orozco Robles]

... I agree with Doug Jensen and his (excellent) recommendations on the Vortex DVD about the look produced when recording 1080-30p ... however, what would be the best rendering settings for producing compatible BluRay files, 60i or 24p ?? ... I just didn´t notice that the BluRay spec. doesn't allow 30p....
...And what would be the best if I have 720p material ??

Kind regards

[Barry J. Weckesser]

Originally Posted by Enrique Orozco Robles

... I agree with Doug Jensen and his (excellent) recommendations on the Vortex DVD about the look produced when recording 1080-30p ... however, what would be the best rendering settings for producing compatible BluRay files, 60i or 24p ?? ... I just didn´t notice that the BluRay spec. doesn't allow 30p....
...And what would be the best if I have 720p material ??

Kind regards

I don't know about 720 but Doug still recommends shooting in 1080 30p to be eventually transcoded into 60i for blu-ray .

[Robert Young]

1080 30p still looks exactly like 1080 30p when transcoded to 1080 60i BR.
Transcoding 1080 30p to 1080 24p BR will not look the same & is an invitation for problems
I believe that 720 30p can stay 30p for 720 BR.

[Brent Ethington]

BR supports 720p60, but no 720p30 (though, 24p and also 50p). there is no "30p" supported in any resolution as part of the spec

[Doug Jensen]

As Robert said, 30P converted to 60i still looks like regular 30P.

Instead of 30 progressive frames per second, what you get is 60 interlaced fields per second -- but every (1/60) field is repeated twice to create the the (1/30) frame.

Visually, there is no difference between one frame that is displayed for 1/30 of a second (progressive), or two identical fields (interlaced) that are each displayed for 1/60th of a second. It adds up to\ he same thing.

FYI, SHOOTING interlaced looks different, because you actually get 60 fields per second that ARE all different from each other.

[Piotr Wozniacki]

Fields are NEVER identical.

I think what Doug means is that with 30p converted to 60i, fields are not offset in time (while when actually shooting 60i, they are).

What you get by "interlacing" 30p (or 25p) is 30(25)PsF, which indeed displays the same as progressive - unless the display device doesn't recognize them properly, and tries to de-interlace using a crude method like bobbing...

[Doug Jensen]

Originally Posted by Piotr Wozniacki

Fields are NEVER identical.

Okay, technically they contain alternating lines so they aren't actually identical -- but if they are showing the exact same underlying image (a 30P frame). In my opinion, for purposes of answering the OP, they are identical.

No, I do NOT mean that they aren't offset in time. Of couse they are. You can't change the specifications of interlaced. Interlaced is always going to be offset. You get two fields -- one right after the other -- but of the same underlaying image. One shows you the odd number lines and one shows you the even. You add the two 1/2 resolution fields together, and you get one full-resolution frame.

Over simplified maybe, but I think it makes the point.

[Piotr Wozniacki]

Doug, of course we're talking the same thing.

I mean the 2 fields, comprising a frame, come from the SAME moment in time as the frame was shot progressive.

From the display point of view; I'd say that:

- when displayed progressively, they should be "weaved" and hence NOT offset in time
- on an interlaced display (CRT) - yes, they are offset in time just like with 60i.

[Doug Jensen]

Originally Posted by Piotr Wozniacki

Doug, of course we're talking the same thing.

Okay, I see what you mean. Two different ways of describing the same thing.

[Enrique Orozco Robles]

very educational tips... great forum.... thanks to all...

kind regards

[Michael Frkovich]

Whenever I record in 30p and down convert to standard def 60i I always see jagged lines
on a crt. It makes no difference how i down convert. I have tried a new timeline or using
a kona card. I always see jagged lines on a crt .

[Barry J. Weckesser]

Originally Posted by Michael Frkovich

Whenever I record in 30p and down convert to standard def 60i I always see jagged lines
on a crt. It makes no difference how i down convert. I have tried a new timeline or using
a kona card. I always see jagged lines on a crt .

What is a crt? (JOKE)

[Craig Seeman]

It would be helpful if "It makes no difference how I down convert" actually included how you down converted. There may be ways you haven't tried that others know of or you may not be doing it the right way.

Keep in mind Doug Jensen shot his EX training DVDs at 1080p30 and they are all absolutely fine as Standard Def DVDs.

Without including specific settings one might conclude you're doing something wrong as Doug's DVDs may verify there is a correct way.

Also note that going to BluRay does not involve a down convert.

Originally Posted by Michael Frkovich

Whenever I record in 30p and down convert to standard def 60i I always see jagged lines
on a crt. It makes no difference how i down convert. I have tried a new timeline or using
a kona card. I always see jagged lines on a crt .

[Greg Boston]

Originally Posted by Piotr Wozniacki

Doug, of course we're talking the same thing.

I mean the 2 fields, comprising a frame, come from the SAME moment in time as the frame was shot progressive.

From the display point of view; I'd say that:

- when displayed progressively, they should be "weaved" and hence NOT offset in time
- on an interlaced display (CRT) - yes, they are offset in time just like with 60i.

Yes they are offset by 1/60, but since you shot 30 frames per second, the first field of odd lines, followed by the next field of even lines will occur in 1/30th (the time required to paint 2 fields). And since you shot in 30P, rather than 60i, the two fields have NO time differential, so they should visually appear to be one complete 1/30 frame on the monitor.

Personally, I like shooting 30P but using a 1/60 shutter setting.

-gb-

[Michael Frkovich]

Originally Posted by Craig Seeman

It would be helpful if "It makes no difference how I down convert" actually included how you down converted. There may be ways you haven't tried that others know of or you may not be doing it the right way.

Keep in mind Doug Jensen shot his EX training DVDs at 1080p30 and they are all absolutely fine as Standard Def DVDs.

Without including specific settings one might conclude you're doing something wrong as Doug's DVDs may verify there is a correct way.

Also note that going to BluRay does not involve a down convert.

Here is how I convert. I set the camera to 1080p. Hook the camera up to a kona card through the sdi out and capture to uncompressed 525i29.97. The image, played back through the analogue out of the kona card onto a crt has jagged lines.

Here is another way I have tried. Record 1080p to an SXS card , import to a 1080p EX timeline. From the timeline I use compressor to convert to uncompressed 525i29.97.
It still has jagged edges viewed on a crt.

Here is the last method I tried. Record 1080p to an SXS card , import to 525i 29.97 timeline and render file. It has jagged lines when played back on a crt.