Shooting 720pN for SD -- Downconversion quality

[David Rothstein]

Since 720pN and DVCPro50 produce equal-sized files, Is there any advantage to shooting 720pN for SD? How does downconversion in an NLE compare with the camera's own downconversion?

I would like footage to perhaps be used for HD down the line, but not at the expense of quality for the SD version.

 

[Derrick_SA]

Generally converting down does not degrade quality. It's when you scale up and information that does not exists needs to be added that you loose quality.

- Derrick

 

[Filmbuff28]

I believe that when you shoot 480 you are recording 60 feilds per second no matter if you're shooting 24p 30p of 60i, then a pulldown is applied to playback the video to match the frame rate used. That is the unique thing about 720pN it shoots 24, 30, or 60 native frames per second meaning no imbedded pulldown or extra fields. So there is close to 2x more information per frame/field in 720pn vs. 480.

Also, if there is the chance of delivering to HD broadcast you cannot make DvcPro 50 real HD. If you are worried that 720 isn't enough then shoot in 1080 24pA and utilize the cameras full chip-set.

Furthermore, I have shot almost all of my shorts using 720pN and then down convert to SD for DVD and it looks outstanding!. But I have now made the switch to 1080 24pA which looks better than 720 and even better on DVD SD.

 

[David Rothstein]

So for the best SD quality I should shoot 1080 24pA? OK.

For now I'll use the 720pN sweet spot.

Thanks!

 

[Ryan Patrick O'Hara]

I believe a long time ago, Barry did some tests with this and if my memory serves me correctly, for Standard Definition, the DVCPRO 50 codec proved slightly better results than down converting 720p to SD.

The difference is so slight that if you wish for a future HD version of your project, shooting HD is the way to go.

PS: Filmbuff, I don't know how your 1080pa footage down converted to SD looks noticeably better than 720p down converted to SD. Please explain if you catch this message

 

[bill totolo]

FWIW, the HVX won't downconvert your DVCpro50 files for you, you have to go through an NLE.

 

[Ryan Patrick O'Hara]

FWIW, the HVX won't downconvert your DVCpro50 files for you, you have to go through an NLE.

Yeah you can not convert 720p or 1080 to DVCPRO50 SD in camera. But you CAN down-convert 720p and 1080i to miniDV SD (4:1:1) in camera using the dub function.

 

[Filmbuff28]

PS: Filmbuff, I don't know how your 1080pa footage down converted to SD looks noticeably better than 720p down converted to SD. Please explain if you catch this message

The difference between 1080pA and 720p down converted to SD is virtually unnoticeable. But the reasoning behind using 1080pa instead of 720p is that if one eventually delivers to broadcast HD then 1080pa is the way to go because there is a noticeable difference between the two HD formats.