progressive vs deinterlacing

[Lars.Erik]

Hello again.

 

Now I now what progressive scan is. And interlace scan.

 

But I'm unsure about progressive vs deinterlacing the footage in post. Pulling it down to 25p from 50i that is.

 

Can someone please explain to me the difference in the two formats.

 

Thanks.

 

LE

[Joshua Provost]

Deinterlacing is the process of removing interlacing artifacts from interlaced footage, and hopefully applying some intelligent algorithm to reconstruct the frames. There are many ways to do this and each software package has a slightly different approach with its own unique pros and cons and sweet spots in terms of the type of footage it can best deinterlace.

 

However, any deinterlacing is only a compromise solution if you can't acquire footage in progressive format, such as progressive video or film. It is a last resort, and there if progressive is an option, then it's a no brainer.

 

The only advantage interlaced has is for slow-motion sequences, when the higher number of sample points in time (50 vs. 25) can result in smoother slow-motion footage.

[Eugene Lehnert]

Interlaced video gives video the look of "video." The extra sampling that is only half the image at a time creates that creepy look of video.

 

Progressive just looks more like film because it is shot more like film. One frame is one frame. With interlaced video one frame is two fields. The first field in DV are the odd scan lines and the second field is the even scan lines. The DVX100 shoots progressive then does what a telecine would do inside the camera so you get footage on tape that looks like it may have been shot with an HD camera or Film camera.

 

There is a cheap program sold on www.dvfilm.com. I shot a feature with the PD-150 and used this to deinterlace all the video. It can convert 60i to 30p or 24p. I'm not sure what PAL options there are but it must support it. The software is nice because it only deinterlaces video where motion is present preserving a lot of the resolution. You can get the same effect in After Effects but it is a little softer. But when viewed on a television off a DVD the difference is negligble.