Sensor cropping issue

[Chris Gavrilovic]

I am certain this has been asked on here, but I couldn't find it with the search function.

Does RED ever intend on allowing us to downsample to 1080 instead of sensor crop to 1080? Obviously the cameras (EPIC and Scarlet-X) don't allow this function currently, but is this something on the table? If RED doesn't want to add it because they don't want to "reduce quality" is this something that can be hacked on the camera to have it done anyway?

Thanks

 

[Terry VerHaar]

I believe you can capture the output from HD-SDI as a clean feed to an external recorder at 1080P. More equipment and not REDcode, but...

 

[Graeme Nattress]

So, to get a downsampled 1080p output you can record the HD-SDI outputs, or you can downsample in post from the RAW file. If you record the R3D as well as the downsampled live output, you've now got the best of both words.

So no, you don't need to, nor should you want to, hack the camera.

Graeme

 

[Nick Pasquariello]

I am certain this has been asked on here, but I couldn't find it with the search function.

Does RED ever intend on allowing us to downsample to 1080 instead of sensor crop to 1080? Obviously the cameras (EPIC and Scarlet-X) don't allow this function currently, but is this something on the table? If RED doesn't want to add it because they don't want to "reduce quality" is this something that can be hacked on the camera to have it done anyway?

Thanks

The question your asking kind of lacks a lot of small pieces of information.

First, the camera can record to the whole sensor. It can record almost all of the entire sensor at a reasonable frame rate (4k at 24 fps).

The camera can feed this signal out of a HDMI or HDSDI cable (but not both at the same time) to a 1080p monitor. This is a downsampled debayered 1080p stream that gives you that full 4K view. You could also capture this feed with a Aja Ki Pro or Sound Devices Pix 240 or similar device, and bam, 1080p from a 4k sensor.

You can also just record via the camera, and end up with R3D files. You can take these files into RedCine-X Pro (free software made by Red) and transcode to 1080p files. This does NOT crop the files.

In both of the cases above, you are now working with, say, ProRes files instead of R3D raws. Sounds bad, but right now that's the workflow for most people: transcode to ProRes, edit edit edit, then conform back to the R3D raws for certain VFX work and color grading.

You don't gain anything by having a downsampled 1080p raw file that was shot on 4k worth of sensor. Except hard drive space. But gigabytes get cheaper and cheaper, so it's really a non issue.

 

[Adam Eden]

If anyone hacks a RED i think Graeme would hack both your arms off!

Joke....

 

[Chris Gavrilovic]

Haha, thanks for the input fellas.

 

[Adam Howden]

Yes, I'd be a big fan of more image color compression etc in preference of cropping the sensor. Cropping the sensor bites, let's face it! I mean if you could do something like 50 or 60 fps at something like 18:1 or similar then, for those that don't need to push our grades to the max would be very very very very very happy!

 

[Mike P.]

Does that mean, through "live view" at 5k, you could record a 5k@1080p image via HDMI/SDI on scarlet or does it still show it at 12fps? I mean, I know Scarlet can playback 5k footage, but I'm not sure what's getting spit out the backend as it passes through the sensor without recording.

 

[Eric J Kosinski]

So, to get a downsampled 1080p output you can record the HD-SDI outputs, or you can downsample in post from the RAW file. If you record the R3D as well as the downsampled live output, you've now got the best of both words.

So no, you don't need to, nor should you want to, hack the camera.

Graeme

So Graeme, are you saying that on the Scarlet we could record 4k using the full 4k frame internal to SDD cards, and simultaneously record 1080P USING THE FULL CHIP (5k or 4K size) being recorded? Not cropped sensor?

if we went out through HD SDI to a unit like the Sound Devices Pix 240 would the aspect ratio change, the sensor crop, or would it be from the metadata from the sensor which would be 4k scaled to 1080p with the same exact image as 4k?

 

[Mike Kushner]

I'm trying to record 1080p from 5K FF or 4K HD on a Nano Flash from the HD-SDI output of an Epic X. I see black borders on the monitor. Seems like the output has scaled the image a bit. Am I doing something wrong or do I have the settings set wrong in the monitor outputs? It looks like the monitor is set on "underscan" but it is not. Would I need to scale the footage back to size before edit? Any light you could shed on that would be much appreciated.

Mike Kushner