2k RAW...which lenses, data rate?

[JD Holloway]

Hey all,

Quick question...are s16mm lenses the only way to get 2k RAW? It would appear so on the red.com diagram.

The reason I'm asking is because I thought the abakus adapter was for B4 lens to s16 film; and should be enough for 2k.

I am I way off? This format is important to me to maximize solid state recording in EFP work etc.
If REDs B4 adapter is in still in development, it would be great to expand its image to cover 2K,
even if it has light loss, or minimal vignetting.. Just need that RAW image possibility.

Also is data rate known? predicted? 1/4 of 4K'ish?

J.

[MikeCurtis]

data rate ought to be ROUGHLY a 1/4 of 4K, but wavelet isn't exactly linear in its behavior to get same quality from differing frame sizes AFAIK. I'd GUESS that it'd be a bit over 1/4 of 4K, so 7-9 MB/sec? Maybe?

[Damien Molineaux]

Hey all,

Quick question...are 16mm lenses the only way to get 2k RAW? It would appear so on the red.com diagram.

The reason I'm asking is because I thought the abakus adapter was for B4 to 16mm/s16mm cameras.

I am I way off? This format is important to me to maximize solid state recording in EFP work etc.
If REDs B4 adapter is in still in development, it would be great to expand its image to cover 2K,
even if it has light loss. Just need that RAW image possibility.

Also is data rate known? predicted? 1/4 of 4K'ish?

J.

Actually, 16mm lenses won't give you 2K raw, and as far as I know, no adaptor for 16mm lenses is planned. What is confirmed is you need S16 lenses to shoot 2K raw, however it does seem the B4 adaptor will enlarge the image so it fills the 2K windowed sensor. So you should be able to use B4 lenses for shooting 2K raw. The question now remains as to the possibilty of shooting with a smaller windowed sensor than 2K, and be able to use n16 lenses ?

You can also shoot 2K with any lens that can shoot full sensor, such as still lenses (Nikons), or 35mm Cine lenses of course. Just remember, that with a 2K windowed sensor, a normal viewing angle is obtained with a 16 or 17mm focal length.

Cheers,
Damien

[tj williams]

Hi Earthling once again the window is changing sizes. Where do you get the information that there is more than one window size, one for 2K and another for HD?

It has been my understanding that the windowed sensor will allow use of S16 lenses or adapted B4 lenses which then cover S16 size imager to record 2K
and when it is perfected in later cameras 1080 and 720. Perhaps I'm wrong here. Please show me the source of your information.

ps Thanks for the figure Mike I have been looking for that.... it's in there somewhere but I couldn't find it then just happened to see your post!!! small data small world.....

[David Newman]

If you have a fixed quantizer, encoding the center 2K would produce exactly 1/4 for data rate (if image detail was evenly distributed.) However, they might as well increase the quality for 2K modes, so there is no predicting the data-rate for Red's 2K. CineForm RAW at 2K averages 12-16MBytes/s for Filmscan 1 (the mode that bested HDCAM-SR -- see me blog for info at http://cineform.blogspot.com) so would hope Red would also choose to quantize less in the 2K modes or offer the user some control.

[Damien Molineaux]

To answer TJ, (sorry for the late response, this thread somehow got lost in this increasingly massive forum), there was talk, at some point, that shooting with the B4 adapter was limited to 1080x1920. Actually that's still what the format options chart indicates, see below, the link to Red's web site is here (http://www.red.com/formatoptions.shtml). I do however believe things have changed and that this chart is not accurate (message to Red !).

To answer David Newman, I recall, if I'm not mistaken, Graeme saying wavelet compression is more efficient on larger images than smaller ones, hence 2K Red Raw ≠ 1/4 the file size of 4K Red Raw.

As to the quality, I would think it to be the same. I believe the goal is to have no visible loss first, small file size second. One of the reasons I want to shoot 2k is smaller file size, so I don't want less quantizing, but user control would be great.

Cheers,
Damien

[David Newman]

To answer David Newman, I recall, if I'm not mistaken, Graeme saying wavelet compression is more efficient on larger images than smaller ones, hence 2K Red Raw ≠ 1/4 the file size of 4K Red Raw.

Technically we are both correct. The same image frame for 2K and 4K, the 2K wouldn't be 1/4 of the data rate of the 4K, as there is more redundancy in a 4K image. The amount of "image data" per pixel depends a lot of the number and sharpness of the edges in the frame. The same FOV yields a similar amount of edge data. On average we see 2-2.5X increase in data rate for every 4X increase in image size. Yet if you point at blue sky, you are primarily encoding sensor noise, the 2k image will be a quarter of the data rate (with the same quantizer.) Problem will letting the data rate naturally fall for 2K, is 2K will be stressed more than 4K, without the oversampling 4K you will want more detail stored per pixel at 2K then you would at 4K. User control over data rate is best.

[Damien Molineaux]

Indeed, we agree. Thank you for your detailed post David. I was actually hoping for the difference between 4k and 2k data rate would be 1/3, if it's only 1/2, I'll have to plan on taking more drives along for travel shoots.

User control would be great, but in my case, quality comes first, file size second, (but I do hope the difference wil be more along the line of 2.5 times).

Cheers,
Damien

[TimothyD]

Hi folks,

My 2 cents: I would definitely hope and pray that it is either user selectable from a few qualities, or that they increase the data rate for 2k until it knocks out any and all comers in the 2k realm (and 1080 for that matter).

Big thumbs up for that idea...

Tim