2K Scaled Is Vital

[DSPographer]

Thom,
The green pixels in your final image do not represent evenly spaced locations on the original sensor, removing the unoccupied rows and columns from step 2 to step 3 means that the green pixels which all have the same spacing in the final image did not come from evenly spaced locations on the original sensor. You are correct that the final image after my scaling is not a Bayer pattern (but it can be stored as one, just place the blue pixels in their proper spot). But it is a pattern where the pixels of a given color are uniformly spaced which is the critical feature needed for reconstructing a proper RGB image. It also averages the closest set of 4 green pixels which is important for minimizing aliasing. Of course other more involved spatial filtering could be used before down-sampling for even better anti-aliasing performance.

[redicule]

back to the original discussion...

Hopefully scaled 2K will be an option soon. Having said that 4K will still be the prefered shooting mode. Its all about quality of aquisition, which is why a 35mm film that has been through a 2K DI can look so great - because it was captured at very high resolution in the first place.

Getting 4K off-speed up to double the base frame rate under normal circumstances would really be an advantage to the camera, as that is what most sync 35mm cameras can achieve. (48-50fps as double the "cinematic" frame rate, although I guess 60FPS could keep a lot of NTSC folk happy)
Under normal circumstances = by setting the frame rate, not by having to attach external recording devices, reconfiguring the camera physically.

Take for example a film shoot with a millenium XL as sync camera and a 435 for high speed. The first version of the millenium XL could only do 40fps, where as the new version can do 50fps. A lot of the time high speed is either double frame rate or really highspeed (as in 96/100fps ++, = 435) So by making the new XL 50fps capable, suddenly the 435 is needed only for really high speed setups (a lot less)

With the first XL, if the camera was on steadicam and the director wanted an option of a take at double framerate, you would have to do a complete rebuild using the 435 to achieve that. On the new XL its a matter of seconds to reset the camera frame rate.

This results in massive time saving and cost for a production.

The point here is at the moment, (talking framerates only) the Red can only match older sync film cameras that can only do 25fps, but can't match any modern high-end cameras, including the genesis, milleniums/XLs, Arricams, etc.

However having scaled 2K would be vary useful, most of which revolves around retaining the DOF. (also consider the FOV change, meaning you will loose wide angle from your lens package).

Another consideration would be the amount of data produced by 4K. Imagine a TVC were you wanted to shoot 2-3 hours per day for a week, for a fast turnaround spot. This would be much more suited to a tape format because the Red would be producing massive amounts of data that would take too long to process to a usable format. Scaled 2K would make the Red a more viable option.

BTW why can you not shoot 4K variable speed UNDER 25fps?

[Thom Steinhoff]

DSPographer,

Okay, thank you--and thank you for your patience--I see your point and since you really sound like you know have far more experience than me on the topic--I'll defer to your experience.

In the end, as you said, the result really needs to maintain the color representation and placement on the sensor as if it had 1/4 the image sensors to alias properly, but still come out the other end with a bayer pattern so it fits in to the same redcode raw workflow.

I've always lived with the concept of vocalising my ideas loudly--so even if I'm wrong I learn faster and maybe the discussion sparks someone to coming up with the right answer.

Since Graeme has remained quiet on this topic--I assume it's because he's sitting on the answer, giggling quietly, waiting to release his raw scaling magic on the world in the form of a working camera.

[Dalibor Fencl]

I wouldn't say Graeme need to think so much about those bayer pattern principles as the downscaling already works fine in REDCINE. The problem is the pretty fast implementation of it inside the RED ONE camera.

[David Mullen ASC]

Does REDCINE downscale 4K RAW Bayer image to 2K RAW? I thought it first converted it to 4K RGB before downrezzing it to 2K RGB.

[Graeme Nattress]

I understand all what you're talking about. The problem with "simple" scaling techniques, raw or otherwise, is the evil that is aliasing.

I know the need for 2k scaled, for high fps full sensor DOF. I know what I have to do.... That's about all I can say.

Graeme

[Greg M]

I think we have the man that can meet the challenge!!

[Larry McKee]

Thanks, Graeme. It helps knowing you are working on it. 4K is very cool, but most of my clients have shown more of an interest in 2k windowed and especially 2K scaled for most of their projects.

[Matt Uhry]

I understand all what you're talking about. The problem with "simple" scaling techniques, raw or otherwise, is the evil that is aliasing.

I know the need for 2k scaled, for high fps full sensor DOF. I know what I have to do.... That's about all I can say.

Graeme

Hi Graeme, Some posts have tried to paint 2k Scaled RAW @ 60P as unimportant and not a priority. Thanks for understanding that it is.

Matt Uhry
www.mattuhry.com

[Dongfang Hong]

I understand all what you're talking about. The problem with "simple" scaling techniques, raw or otherwise, is the evil that is aliasing.

I know the need for 2k scaled, for high fps full sensor DOF. I know what I have to do.... That's about all I can say.

Graeme

Graeme, thank you for acknowledging our need and its importance to us.