Redcode and s35 Aspect

Stephen W

Stephen W

Well-known member
I was thinking about Redcode Raw 4k, which will shoot at up to 30fps in 16:9, then got thinking about s35 ratio (let's call it 2.4:1 for the sake of argument!) and how best to use the full image sensor.

The thought that occured to me is that (using a windowed mode) would it be possible to take advantage of the full sensor width (4520) in a 2.4:1 ratio and still record using Redcode?

It seems to me that, for that big widescreen cinema experience, it'd make sense to shoot say 4520x1890 - making full use of the frame width whilst saving on the height. Compared to 4096x2304, I believe you'd actually have a slightly lower data-rate (it's actually about a million pixels less). It seems at the moment if you want to shoot 2.4:1 using Redcode, you'd have to do it 16:9 and then crop it, which seems a waste of data.

If we could get a slightly higher horizontal res but at a lower data-rate, surely it'd make sense?
 
Valid point. I would suggest maybe since RedCode can handle the number of pixels in 4k, it might be worth using that full data rate in 4.5k 'wide'. That would be about 4520x2080 (2.17:1). I know that's a non-standard format, but I believe so is 2540p.

Doing this would alow for on-camera recording, but with the maximum resolution to allow for re-racking in post, both horizontally and vertically, and still producing a 4k master.
 
I have been wondering about this too. It makes a lot of sense to maximise imaging area on the sensor, though I wonder if the lens is going to be the limiting factor to resolution in this case.

If you use the full sensor area with a S35 lens you will get a wider FOV. Can most S35 lenses support this or are you going to start getting some vignetting at the lower focal lengths. Or is it only really appropriate using the full sensor area if you are using still lenses?

Martin
 
I would have thought it is the full sensor that is s35, so cine-lenses should cover it with no probs. In fact, the stuff Jim's been shooting it 4.9K I believe and he's used the Red 300mm, Cooke s4 and (I think he said somewhere) Zeiss lenses.
 
Stephen W said:
I would have thought it is the full sensor that is s35, so cine-lenses should cover it with no probs. In fact, the stuff Jim's been shooting it 4.9K I believe and he's used the Red 300mm, Cooke s4 and (I think he said somewhere) Zeiss lenses.
Click to expand...

I think you are probably right. So if you shoot 4k windowed you are cropping the S35 frame
 
That makes sense. Looking at the Red tech specs page it says:

Physical Size: 24.4mm x 13.7mm (Super35mm)
Active Pixel Array:4520 (h) x 2540 (v)
Full Pixel Array:4900 (h) x 2580 (v)

Matching up the aspect ratios, it makes sense that the 24.4mm equates to the 4520 pixels, not the 4900. That does mean that only 2540p is 'true' Super 35 frame size. 4k is technically only the centre 90% of a Super 35 frame.

The fact that the stills we've seen come from the full 4900 wide certainly seems to imply that there is a reasonable amount of 'overscan' to use a video (sorry) term on both the Cook and Red primes.

Nick
 
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