1080p... Not a loser!

[Häakon]

Suggestion for a possible solution
I’m not an engineer, but I would guess that RGB 720p/120fps is actually a higher data rate than RGB 1080p/60fps. Jim has stated that RGB 720p/120 or 2k RC RAW/96fps is an either/or situation – both are not possible. There seems to be many people OK with losing 720p/120 to gain 2k/96fps, but they also want to keep 1080p/60. If 1080p/60 is a lower data rate than 720p/120, it just may be technically possible to finalize the specifications with 2k/96fps and 1080p/60 and still keep within the sensor limits using VBR (variable bit rate) manipulation...

...I think RGB 1080p is very important to keep in the camera specs for many of the reasons myself and others have posted on the “1080p and 720p…losers” thread. I'm fishing for a compromise that would allow 2k/96 and 1080p/60 to both be in the final specifications.

I agree with you completely Gibby; 1080p is essential - aside from instant deliverables, it's the only way (at this time, anyway) to keep (onboard) 60fps alive from the full 4K sensor. That's a big deal to many people here.

However, (and I'm not an engineer by any means possible - so take this post with a grain of salt), I would speculate that it's not the bandwidth of the recorded frame that's the problem (after all, you wouldn't be recording 720p/120 and 2K/96 at the same time) but just space on the FPGA itself for coding instructions/format choices. In other words, while the sensor is potentially capable of doing 96fps at 2K AND 60fps in 1080p RGB AND 120fps in 720p RGB, there may not be room on the FPGA to embed and deal with all of the conversion instructions. As long as you have a fast enough pipeline (CF card, hard drive, whatever), the bandwidth isn't the issue. That's how I'm interpreting it, anyway.

And you're right, we haven't heard back yet if nixing 720/120p will still allow the provision for 1080/60p - which is the critical question. I think if enabling 2K/96p is possible - but only at the expense of both 720 AND 1080 - many people will have a problem with that. Here's hoping to hear back from RED soon!

 

[Poi Boy]

Shooting 720 at 120fps you are windowed as with 2k at 96fps. At 2k you are giving up 24fps but are getting much higher resolution and not giving up raw. Off course you light and balance when you shoot but you have so much more control if you stay raw.
Aloha
-A

 

[donatello b]

"take away 1080 RGB, I cannot shoot the overcranked scenes I need "

ok you cancel your RED and replace it with ??

or you could do what many will do - rent a hi speed camera for the days you need it = 120fps is no longer your limit ...

 

[Blair S. Paulsen]

Love it RAW

Love it RAW

One bit of clarification - several posters are comparing 1080P downsampled from the full sensor versus 2K RAW windowed. I thought the two available choices were 720P downsampled from the full sensor @120fps versus 2K RAW @96fps windowed.

Assuming a 2K or 1080P finish, the 720P @120fps option would require an up-rez in post which the 2K option would not. Without testing there is no way to know just how the up-rez from 720 would impact the image but...

Until we can test it's just a guess, but I am thinking that intercutting 4K RAW and 2K RAW overcrank will be easier since both have the latitude and gamut of RAW color space. DoF issues might require some adjustments but since the faster shutter will generally require a bigger aperture with the same light levels it should be doable.

I still think that if you need to go beyond 96fps you should just rent a Phantom - horses for courses.

 

[Poi Boy]

According to the faq 720@120 is s16 sensor crop.
-A

 

[Tom Lowe]

Häakon, let me expand on the point you made about a downsampled 4K-to-1080 image having much less visible noise than a cropped/windowed 2K image. This tends to be especially true when shooting in low-light conditions, like during sunsets. My guess is that 4K downsample to 1080 will be the superior image vs the 2K windowed.

Only way to know for sure is to run some tests. Gibby, any chance you could incorporate such a test in LART? Maybe turn Mlullen loose for some exterior sunset shots?

 

[Peter McCully]

....And you're right, we haven't heard back yet if nixing 720/120p will still allow the provision for 1080/60p - which is the critical question. I think if enabling 2K/96p is possible - but only at the expense of both 720 AND 1080 - many people will have a problem with that. Here's hoping to hear back from RED soon!

I tend to agree here. If only because of the amount of 1080p production that my Red would be used for. It's another reason for producers to say yes. Even if the advantages are percieved rather than real. Naturally 2K and 4K are the big daddys but I can foresee much of the future output being 1080.

 

[Bruce Allen]

Gibby,

1920x1080x60 = 124 million pixels / sec
1280x720x120 = 110 million pixels / sec

So, uncompressed, they are comparable.

When you compress them, which one is bigger depends on whether your compression occurs primarily in the spatial or temporal dimension. It's possible there will often be less drastic frame-to-frame changes for a lot of 120fps footage. But the 1080p footage will probably have less detail per pixel than the 720p.

REDCODE is spatial only, right? So I'd expect the 1080p stuff to compress better.

Bruce Allen
www.boacinema.com

 

[Häakon]

According to the faq 720@120 is s16 sensor crop.
-A

Further expanding on that, according to the current format options page, it is possible to scale to 720p from the full sensor - but only up to 60p (as that's the max framerate the full sensor is capable of).

So perhaps that's the missing piece? Since there are actually two ways to get 720p out of the camera (currently, or at least according to the website) - perhaps getting 96fps out of the 2K mode means nixing the scaled-from-the-window flavors of RGB. Just another thought.

 

[Poi Boy]

I think we have beat this to the ground, we need some JJ clarification.
Aloha
-A

 

[Jim Arthurs]

My guess is that 4K downsample to 1080 will be the superior image vs the 2K windowed.

The only way that this wouldn't be true is if the on-board hardware downscaling/processing winds up only being of "monitoring quality". I firmly hope this isn't the case. Maybe that is a behind the scenes reason behind some of the re-thinking of legacy HD formats? Again, I hope not.

I've been a strong proponent of the downscaled 1080p RGB since announced. It's the closest thing RED offers to a "hand over and walk away" deliverable.

 

[Häakon]

One bit of clarification - several posters are comparing 1080P downsampled from the full sensor versus 2K RAW windowed. I thought the two available choices were 720P downsampled from the full sensor @120fps versus 2K RAW @96fps windowed.

Those are the two options Jim put out, but he also mentioned that both "720p and 1080p are losers," and some of us are just concered about losing both RGB formats in order to enable 96fps in the windowed 2K mode. Since the 1080 variant is quite close in size to 2K - and it allows for up to 60fps in that mode while preserving the image characteristics of the full 4K sensor - it's the one RGB option that many of us are concerned about. If 1080p/60 RGB is not in danger of being removed, then the choice between 720p/120 and 2K/96 is really just a personal choice... what's more important to you, high speed or image quality? That of course completely depends upon if you have a need for high framerates in the type of shooting you do as well as if you plan to do a lot of windowed shooting. For me, the 1080p/60 scale from the full sensor is more important than any of the windowed formats... but that's just my personal preference.

 

[Bruce Allen]

No, AFAIK, the 720 @ 120 is also downsampled from a cropped sensor. I don't think Red is capable of reading out the entire sensor at 120fps.

If you look at DSLRs you'll see a similar phenomenon. You can read out twice as fast if you window.

Bruce Allen
www.boacinema.com

 

[Häakon]

AFAIK, the 720 @ 120 is also downsampled from a cropped sensor. I don't think Red is capable of reading out the entire sensor at 120fps.

That's correct, but the format options page shows that up to 60 fps is possible at 720 from a sample of the entire sensor. So perhaps they can keep 720p/60 (and along with it, 1080p/60) to enable the magic 2K/96 barrier and only have to sacrifice the windowed RGB options. Hence, what do you prefer - 720p at 120, or 2K at 96?

 

[Poi Boy]

My ideal would be 1080p60 and 2k96; lose 720 all together.
Aloha
-A

 

[Jeff Kilgroe]

One bit of clarification - several posters are comparing 1080P downsampled from the full sensor versus 2K RAW windowed. I thought the two available choices were 720P downsampled from the full sensor @120fps versus 2K RAW @96fps windowed.

720p @ 120fps is only possible from the 2K window (s16mm) area of the sensor. It can not scan the entire s35mm 4K area at rates higher than 60Hz.

The 1080p RGB scaled from the 4K sensor area is a must. It's the only way to get the full 35mm sensor area at 60Hz recorded onboard. It's also a practical format to be able to record for EFP / Broadcast applications and even cinema depending on certain factors.

I think we do need some clarification though. I've interpreted Jim's posts a bit differently than most everyone else it seems. I took it as he was considering the elimination of onboard RGB recording. As in do we really need onboard ability to record 720p and 1080p? Many people said they were interested in these modes, primarily 720p because of 120fps capability.. To which the question was put if the RGB modes were eliminated, would 2K windowed RAW recording suffice for those in need of overcranking? -- particularly if it were capable of up to 96fps, which looks to be possible.

Anyway, I think I've seen several of us (myself included) post the same sentiments in several threads, perhaps it's time to start locking some of these down.

 

[David Battistella]

Anyway, I think I've seen several of us (myself included) post the same sentiments in several threads, perhaps it's time to start locking some of these down.

AMEN!

This has been a RED marathon!

David

 

[Casey Green]

1) Can a software app. come with the Camera that allows the User to flash the firmware and thus allow for individual choice of supported modes? (this is based on the idea of the programmable FPGA which we have been told we can upgrade with firmware already, no?...... then no one loses functionality; those who want 2K@96 change the firmware for that mode, those who want 720, or 1080 use a different firmware rev. Also, this may allow for other possible 4K modes... )

2) If not, if 720p is dropped and 1080p is still kept, will this still allow for 2K@96fps? (if so, this is not a bad compromise.)

3) What is the RedCine down-res processing time? (And what factors go into this calculation? Is it different on faster CPUs?)

I know Jim wanted to let this sit for a day or two to get our responses... when we get the answers to these questions, it will make the decision a bit easier to make.

Your "Big three" questions summarize the core of the issues well Casey. Let’s review what Jim said…and didn’t say, plus a comment about variable bit rate form Stuart English...

...Suggestion for a possible solution
I’m not an engineer, but I would guess that RGB 720p/120fps is actually a higher data rate than RGB 1080p/60fps. Jim has stated that RGB 720p/120 or 2k RC RAW/96fps is an either/or situation – both are not possible. There seems to be many people OK with losing 720p/120 to gain 2k/96fps, but they also want to keep 1080p/60. If 1080p/60 is a lower data rate than 720p/120, it just may be technically possible to finalize the specifications with 2k/96fps and 1080p/60 and still keep within the sensor limits using VBR (variable bit rate) manipulation. I’m outside my area of core expertise in making that suggestion, so I’m just asking of it would be possible. If not, can a slightly lower fps in 2k enable the keeping of 1080p/60?

I think RGB 1080p is very important to keep in the camera specs for many of the reasons myself and others have posted on the “1080p and 720p…losers” thread. I'm fishing for a compromise that would allow 2k/96 and 1080p/60 to both be in the final specifications.

Food for thought…

Thanks Gibby,

(not going to quote all the sources here, however...)

I agree with Haakon, where I'm not so sure the variable bit rate is a factor here. And this is well beyond my expertise, but it seems as if the FPGA can only hold so many instructions or "format modes" if you will. If my understanding is accurate (it may be WAY off) and that is the case, perhaps the Firmware mods are possible, and that would be just great... Have the Camera ship in a standard mode (possibly in the state that was advertised), and then include the software app which allows the user to upload their own customized modes...

That could mean eliminating ALL non-4K modes for some and increasing the 4K fps to the max, including higher 2K modes, or even possibly allowing only the highest 720p or 1080p framerates.

I suppose there would be some marketing issues to work through, but we all know RED is great in that dept.

OK... I think I'm done on this one. Anxiously awaiting RED's response.

And thanks again to RED and this amazing community for presenting us the opportunity to be this involved in the development process. (I've been charging $5 a letter for my posts, how about you guys?) :wink:

 

[Michael Lindsay]

1080p @ 60 = 1920x1080x30x60 = 445MB/s then compressed
4k raw @ 30 = 4096x2304x12x30 = 405MB/s then compressed

Couple of thoughts:

There is perhaps some more capacity to be squeezed out since already the 1080p image is both higher bandwidth and more complex in process... Maybe Red could give us a 3k image (windowed) at 60fps it would be about the same pre-compression (post matrixed) data rate as 1080p60?.. you'd have to use 35mm glass but it could be a nice compromise???

Also a 4k windowed image that had a 2.35 to 1 ratio at 45fps would have a very similar pre-compression data rate to 1080p60fps..

Perhaps it is possible to record short bursts of 4k@60fps without a fridge even if sustained many minute takes are not possible....

Also since larger images compress more gracefully I would like to see the quality of the RGB 1080p image compared to a 2kcrop...

regards

Michael

 

[mezmo]

Hi guys,
I'm not a reservation holder here so I don't have much clout,
but I do plan to hire two of the early cameras for a project
next year.
I need cameras that will deliver excellent pictures a 24fps and
high speed.
96 fps would be fine, the intercut between these framerates
must be seamless as post ramped shots will be intercut with 100%
24fps dialogue shots.
Lets face it, Red is not a high speed 4K digital film camera.
Without testing it's hard to determine the quality of highspeed 2K
intercut with 4k.
Loosing 35mm D.O.F. to shoot highspeed I see as a major problem
and don't see this as any sort of option.
I also see this as an important issue with this camera if it's to be used in a
high end professional enviorment.
We can do all this with film, the benchmark. It's as expensive as hell
running two 35mm cameras at high speed on a film set but it's simple
and works well with no noticable quality loss.
Red needs to achieve this with the same results if it's going to compete
in this area,
and this I think should determine what the camera is and where it should
be in the marketplace.
A second cheaper model for 720/1080p could also be an option for the
video based guys.
Cheers Mezmo