2K croped to 1080 or scaled ?

[Antoine Fabi]

Hi,

1) When they scan film in 2K, do they then crop it to 1080 DVD or do they scale it ?

2) What is best for image quality ?

thanks

Antoine

 

[Uli Plank]

Usually it's cropped, only CS gets letterboxed. BTW, DVD is SD, only BluRay is 1080.

Quality isn't much of an issue if you use good scaling algorithms, but cropping should look a tad better.

 

[Antoine Fabi]

Yes...i meant BluRay...

So it should look a little better when cropped because it's 1 for 1 pixel ?

thanks

Antoine

 

[Uli Plank]

Yessir.

 

[Brandon Fraley]

Yes...i meant BluRay...

So it should look a little better when cropped because it's 1 for 1 pixel ?

thanks

Antoine

why would that be? wouldn't I an oversampled image always look better than 1:1?

 

[Antoine Fabi]

Brandon,

Maybe 2K and 1080 are so close...maybe too close.

 

[Ryan Valle]

why would that be? wouldn't I an oversampled image always look better than 1:1?

Dont have any experience in scaling with the RED media, but from experience, it seems like you cant get nice scaling results if you dont scale in "even" scales such as 2:1 or 4:1. Say if you scale it in 1.33:1, you'll may end up with weird results since it will result in an uneven scaling ratio. If you use photoshop, you can see what I mean when you compare 100%, 75%, 50%, 33%, and 25% scaling factors. You wold notice that the 33% has a weird look and the pixels are shifted in some fashion. In theory (or atleast my theory), I think this same effect would happen if you tried to scale 2K media into 1080 since they are so close that scaling won't be at some round factor like 2:1. I hope all of this makes sense.

 

[Daniel Browning]

If you use photoshop, you can see what I mean when you compare 100%, 75%, 50%, 33%, and 25% scaling factors. You wold notice that the 33% has a weird look and the pixels are shifted in some fashion.

The "zoom" scaling algorithm used in Photoshop, even CS4, is rubbish. Do the same experiment with any well-written program, such as ImageMagick, and you will see that there is no weird look or shifted pixels.

I cannot fathom why Adobe would inflict so much pain on the world, year in and year out, with their braindamaged zoom tool.

 

[Ryan Valle]

The "zoom" scaling algorithm used in Photoshop, even CS4, is rubbish. Do the same experiment with any well-written program, such as ImageMagick, and you will see that there is no weird look or shifted pixels.

I cannot fathom why Adobe would inflict so much pain on the world, year in and year out, with their braindamaged zoom tool.

Well, since this is the Apple Workflow section, I assumed Final Cut pro and from what I noticed and recall, you would see a similar effect in final cut's scaling. I havent worked with RED footage or anything above 1080, so I am just speaking from theory based on past experience with previous formats. In other words, my assumptions are based on taking in the 2K image and then scaling it to a 1080 sequence using the basic motion settings within final cut. I am sure there are other ways to do this scaling it during import when encoding the video to ProRes or other format or editing in full 2K then scaling it after editing. I am no Final Cut master so I am sure I could be wrong in many places, but I couldn't emphasize enough that I am speaking from theory based on past experiences with 1080 and below media.

 

[Uli Plank]

FCP doesn't use the greatest scaling algorithms in the world either. And the initial question was about scaling from 2K, for that case I'd recommend cropping.

Downscaling from 4K with REDLine (used by RR and Clipfinder too) wil give you a wide choice of algorithms and excellent downscaled footage because of the massive supersampling.