4k R3D from 8k sensor? Full frame, no crop?

[Jarek Zabczynski]

Ok, so I know this was never possible with raw on Red cameras. But now since we've moved to an 8k sensor, wouldn't it be much easier to do now with some sort of line skipping etc?

I'm currently waiting for my Helium 8k upgrade, but I notice now how much I struggle sometimes with my 6k Weapon when I crop down to 4k, something I do pretty often when I don't need all the extra resolution. I'm thinking I might shoot more 4k prores with 8k Weapon, but the sweet spot would be to get full 4k r3d glory off the full sensor.

Thoughts?

 

[Phil Holland]

Shoot 8K REDCODE RAW export at 1/2 or 1/4 debayer?

It's been said a lot, but REDCODE RAW is a Compressed RAW format. No scaling.

Best solutions are what I mention above or a 4K Intermediate Codec in camera like ProRes or DNxHR.

 

[Jarek Zabczynski]

Yeah, I figured that. I thought maybe with an 8k sensor, it might open up some new opportunities for shooting 4k at full sensor.

 

[Graeme Nattress]

RAW really doesn't downsample well. For best results shoot 8k and downsample afterwards.

Graeme

 

[Andrew R Lewis]

RAW really doesn't downsample well. For best results shoot 8k and downsample afterwards.

Graeme

The biggest problem I am having with many clients is them just wanting to shoot 4K Raw with no crop. They want a single 4K Raw file, no duel recording. It's become an issue. I push for 8k and downspling but doesn't always work. Guess I need more media to help them rest easy.

 

[Jarek Zabczynski]

The biggest problem I am having with many clients is them just wanting to shoot 4K Raw with no crop. They want a single 4K Raw file, no duel recording. It's become an issue. I push for 8k and downspling but doesn't always work. Guess I need more media to help them rest easy.

Agreed. I always shoot the highest my camera can do for my projects. But I'm also running into clients that want 4k raw. Shooting cropped on a 6k sensor is already limiting. 4k on Helium will be tough. I wish there was some magic line skipping mode that recorded a 4k raw image off the 8k sensor. 4k Prores will probably be my goto for stuff like this, but 4k raw would be awesome.

 

[paulcurtis]

Exporting 8K down to 4K with RWG/LogG10 is going to give you pretty much all the range from the camera in a container that could almost be pushed anywhere. It's an amazingly capable master file. And you have the benefit of an 8k -> 4K scale in there that 4K RAW would not get you.

I'd suggest showing some comparisons, all those carefully crafted IPP2 transforms will work perfectly.

IMHO 4K ProRes 4444 in that format down sampled from 8K RAW will produce a better image than 4K RAW because of oversampling...

cheers
Paul

 

[Hrvoje Simic]

Ok, so I know this was never possible with raw on Red cameras. But now since we've moved to an 8k sensor, wouldn't it be much easier to do now with some sort of line skipping etc?

I'm currently waiting for my Helium 8k upgrade, but I notice now how much I struggle sometimes with my 6k Weapon when I crop down to 4k, something I do pretty often when I don't need all the extra resolution. I'm thinking I might shoot more 4k prores with 8k Weapon, but the sweet spot would be to get full 4k r3d glory off the full sensor.

Thoughts?

You'd loose chroma resolution and have lower than 4K final resolution in RGB if that was possible.
8K Bayer scaled to 4K gives you a) clean scale and b) full 4K resolution with zero visible quantization.

 

[Antony Newman]

Jarek,

Is the problem the perceived file size, or desire to minimise post effort?

+) If recording at 8k @ 20:1 compression produced a higher quality demosaic UHD image than a 4K @ 5:1,
would your clients be happier?

+) The clips would have the same file size. Clients could use 1/2 or 1/4 or 1/8 Debayer (as Phil suggested) for speed in post, and would have the flexibility of having a thicker negative when a Full Debayer was called for.

Perhaps the above (if my understanding is correct) is a white paper best penned by RED?

AJ

 

[Graeme Nattress]

The question is why would a client want 4k raw? I guess how I think is if you record 8k raw and do a 2:1 decode (rather than a full demosaic and downsample) you get 4k out just as if you'd recorded a 4k raw but it will look better as there's no line skipping to produce it. You're just dropping the 2nd green component from the bayer quad, and that will making things a tad sharp and perhaps open you to a little aliasing. There's also not that much greater file size than if you recorded 4k raw RGB.

Graeme

 

[Jarek Zabczynski]

I understand and fully agree about downsampling later. Some clients do not however. They ask for 4k raw at the end of the day on a drive and would say:

"Why is this 6k? Or 8k? I didnt ask for that. I don't want to deal with that. I asked for 4k."

It's kinda the same argument we had about wanting to shoot prores instead of r3d back in the day, and we were told when hell freezes over! :devil: Just discussing options is all. I don't think any of us would complain about being able to shoot 4k raw full frame on Helium as an option if it were somehow technically possible.

 

[Alexander Thomson]

Line skipping is not an option. I'd drop RED like the Falcons dropped the 25 point lead if they implemented line skipping as a data conservation method. But hell would have to freeze over first.


I think what the client wants vs what they actually need aren't quite synced up here. A heavily compressed 8K file will in most cases look better than a thicker 4K file. Especially a line skipped one.

 

[jordan levy]

The question is why would a client want 4k raw? I guess how I think is if you record 8k raw and do a 2:1 decode (rather than a full demosaic and downsample) you get 4k out just as if you'd recorded a 4k raw but it will look better as there's no line skipping to produce it. You're just dropping the 2nd green component from the bayer quad, and that will making things a tad sharp and perhaps open you to a little aliasing. There's also not that much greater file size than if you recorded 4k raw RGB.

Graeme

this is exactly why, because its a process, and post production wants the least process possible in a production.
especially with TV.
the times i've shot 5k because i could when the first epic came out, i got reprimanded by post producers. now all tech specs for the shoot i get either say 4KHD R3D raw or 2k proreshq 4444.
as ive seen with the process is that we obviously transcode the exact spec the editor and post producer want to edit with, and we capture the exact spec they want to go back to do color correction with, obviously having the most time for them and least amount of data space. time and space is money.
so i have the exact same issue, im shooting with 6k weapons and can only capture 4KHD mandated from the post production producers, and this is for shows on CBS, NBC and Comedy Central.

 

[Sabovic Adis]

I understand and fully agree about downsampling later. Some clients do not however. They ask for 4k raw at the end of the day on a drive and would say:

"Why is this 6k? Or 8k? I didnt ask for that. I don't want to deal with that. I asked for 4k."

It's kinda the same argument we had about wanting to shoot prores instead of r3d back in the day, and we were told when hell freezes over! :devil: Just discussing options is all. I don't think any of us would complain about being able to shoot 4k raw full frame on Helium as an option if it were somehow technically possible.

Give'm Red One! :biggrin:

 

[Jarek Zabczynski]

Line skipping is not an option. I'd drop RED like the Falcons dropped the 25 point lead if they implemented line skipping as a data conservation method. But hell would have to freeze over first.


I think what the client wants vs what they actually need aren't quite synced up here. A heavily compressed 8K file will in most cases look better than a thicker 4K file. Especially a line skipped one.

I know that, you know that, many clients don't.

I'm not one to say I know how r3d works. But in theory, wouldn't it be possible to translate the 8k raw sensor data and using a half debayer, record it as 4k raw in camera? Or something to that effect?

I only bring up these questions since now with 8k chip we only divide by 50%, vs trying to do this with a 5k or 6k chip. If such a thing were ever possible, now it should be easiest no?

Remember, I'm only talking about this stuff as an option, you don't have to use it. Lot's of people will never shoot prores, but it's nice to have.

 

[Jarek Zabczynski]

Jarek,

Is the problem the perceived file size, or desire to minimise post effort?

+) If recording at 8k @ 20:1 compression produced a higher quality demosaic UHD image than a 4K @ 5:1,
would your clients be happier?

+) The clips would have the same file size. Clients could use 1/2 or 1/4 or 1/8 Debayer (as Phil suggested) for speed in post, and would have the flexibility of having a thicker negative when a Full Debayer was called for.

Perhaps the above (if my understanding is correct) is a white paper best penned by RED?

AJ

Again, you're preaching to the choir. If a client asks you for 4k raw, you don't give them a lecture on why they should want something else or how I'm gonna shoot something else and then tell them how to work with it later.

 

[Mike Finegan]

I know that, you know that, many clients don't.

I'm not one to say I know how r3d works. But in theory, wouldn't it be possible to translate the 8k raw sensor data and using a half debayer, record it as 4k raw in camera? Or something to that effect?

I only bring up these questions since now with 8k chip we only divide by 50%, vs trying to do this with a 5k or 6k chip. If such a thing were ever possible, now it should be easiest no?

Remember, I'm only talking about this stuff as an option, you don't have to use it. Lot's of people will never shoot prores, but it's nice to have.

Lots of extra circuitry to do in real time!!!$$$
In an ideal world there would be realtime interpolation where you could capture full sensor but save scaled down r3d - so expose 8K but save 5K (same aspect). Unless simple drop every other pixel to get 1/2 spatial resolution it requires non-trivial calculation. Some cameras (a7r2 for example) can do simple nearest neighbor 'interpolation' but only for one preset output resolution (FF 4K out) - for S35 they just crop 4K center cut.
Of course we would all want that you would not have to crop unless high frame rate.
But for your specific application just suggest prores 4K - will they even notice prores versus raw if they only want 4k master?

 

[Jaimy Soares]

Again RED is on the train again earlier than enyone else.

Just crop to 4K, don't say anything use wide lenses your done.

Raw 4K.

I know sometimes people force us to do things you don't want. But sometimes there is no other option.

If you/they can't live with the crop go scarlet, raven or epic MX.

 

[Alexander Thomson]

What's stunning is 8K HD @ 10:1 and 6K HD @ 6:1 are similar in data rate, and yet the 8K file will typically yield a better image.

You can lead a horse to water but can't make 'em drink. This whole "can't work with 8K files" feeling just seems like FUD. For those clients, there's RedLogFilm + 4K ProRes.

You can't say a RED isn't flexible.

 

[Marc Wielage]

Ok, so I know this was never possible with raw on Red cameras. But now since we've moved to an 8k sensor, wouldn't it be much easier to do now with some sort of line skipping etc?

I think you're worrying about theoretical problems that don't really exist in real life. Talk to your post crew and ask them what they need to get the job done. I think for most studios, 4K DPX or EXR debayered and downrezzed from the Raw is going to be more than enough.

It never hurts to shoot tests, if you really want to confirm the workflow.