1080p... Not a loser!

[number6]

The real issue here is DOF. 2K windowed won't have the same DOF/lens characteristics as 1080 scaled.

Jason, wasn't the increased ISO numbers supposed to help with the DOF limitations?

 

[Michael Ragen]

I remember a while ago Jim said he plans to shoot almost exclusively with the Red-Ram and I would imagine he would want to shoot higher than 30fps sometimes at 4k for races and whatnot. It will be interesting to see what the near future holds...

 

[Andrew Kimery]

Brainpouer is like a lense... turned one way it concentrates light to it's highest intensity, while turning the lense around scatters it.

And if the "scattered" beam revealed something useful in a shadowy corner that the "focused" beam did not...


-A

 

[Tom Lowe]

The #1 issue I have been talking about, over and over and over again, since day one, is being able to overcrank. My dream would be 60fps at 4K REDCODE RAW onboard. But I am willing to settle for 1080 RGB scaled down from 4K, even though this means I will have to lower the overall resolution of my entire movie to 2K (lowest common denominator), so the 4k RAW and 1080 RGB will match up.

This is a compromise I have made peace with. But if you take away 1080 RGB, I cannot shoot the overcranked scenes I need (dozens of very specific shots I have in mind for my feature next summer) with my 35mm lenses. I am planning to buy or rent a set of very fast 35mm primes for the shoot, and I have no interest in renting a second set of 16mm primes.

I guess in theory that I could use really wide 35mm primes on the windowed sensor...? I don't know...

 

[Poi Boy]

I understand what you want; for me I would rather have the higher quality and higher frame rate of 2K@96 in exchange for having to reframe my shot or renting a lens on occasion. We will have to wait and see but it is exciting that higher rates are being talked about as a possibility.
Aloha
-A

 

[Costelloe Michael]

Guys,

Whatever your theory about the best way to deliver or dof issues 120 fps makes the camera marketable in the real world differently to 96fps. 120fps would be a real bonus for TV work as a high speed camera in special applications such as stunts, esp in the UK.

You may think the % is small but the perception is large. I can see it would make a difference in marketing for this application.

Having said that I don't intend to use it for that purpose but I can see that others will.

Mike C

 

[Tom Lowe]

I like higher frame rates, for sure, but I'm not so sure that 2K windowed is going to be a higher quality image than 1080p downsampled from a full-size sensor. If you use DLSR images as an example, a downsampled 2K image from a 4K Canon 5D shot will be far superior to cutting/cropping out a 2K image from a 4K image, if you follow my meaning.

Some tests should be done on this, but my guess would be that the downsampled 1080 RGB image should look beautiful and would probably be better than a windowed 2K image. A windowed sensor will not have the benefit of downsampling, nor will it have DOF to match the 4K REDCODE stuff.

I could be totally wrong about all this. I'm not an expert on such things.

 

[Poi Boy]

I don't think anyone will not buy Red because of 96 versus 120.
-A

 

[Häakon]

Jason, wasn't the increased ISO numbers supposed to help with the DOF limitations?

Higher ISO means being able to close down lenses (and in effect, expand your DOF). This may "help" you or not, depending on your preference. It makes focusing easier as you have more room to play with, but the shallow DOF is what many people are wanting from the 35mm sensor in the first place. Also, higher ISO means more noise; what is an "acceptable" level of noise will vary from user to user, but many will want to shoot in the cleanest space they can - lenses permitting.

 

[Poi Boy]

with 1080 rgb you don't get raw, that is bigger for me than the cropping. I don't think the cropping will degrade the image significantly.
-A

 

[Costelloe Michael]

I don't think anyone will not buy Red because of 96 versus 120.
-A


I think you're probably right, but it would be a shame to exclude a feature that attracted people to the camera in the first place...

Mike C

 

[Poi Boy]

I don't think anyone will not buy Red because of 96 versus 120.
-A


I think you're probably right, but it would be a shame to exclude a feature that attracted people to the camera in the first place...

Mike C

I take your point. Speaking for my use I'd give up 24 frames to avoid 720 and still get great slomo at a higher resolution; I'll be a pig in shit either way.
Aloha
-A

 

[Costelloe Michael]

but the shallow DOF is what many people are wanting from the 35mm sensor in the first place.

Surely we are talking about the difference in dof between 35mm and 2/3rd inch chip cameras being an issue? ie the 'video' look we all hate? Or am I missing something here?

Mike C

 

[Tom Lowe]

with 1080 rgb you don't get raw, that is bigger for me than the cropping. I don't think the cropping will degrade the image significantly.
-A

Hard to say. RAW is awesome, but again, you then lose the DOF, plus you have to deal with a focal-length magnification factor on your 35mm lenses.

I would really be interested in seeing a Pepsi Challenge of 2K RAW windowed footage vs 4K downsampled to 1080 RGB. Generally speaking, downsampling seems to work far better on these types of CMOS sensors, rather than windowing/cropping.

 

[Costelloe Michael]

Higher ISO means being able to close down lenses (and in effect, shrink your DOF). .

Haarkon Surely closing down your lenses does exactly the opposite of this. It increases your dof.

Mike C

 

[Costelloe Michael]

you have to deal with a focal-length magnification factor on your 35mm lenses.
.

Funny this... we've been dealing with this in the UK for quite a while. Domestic TV S16mm and Features 35mm. I've got so used to it it seems second nature to calculate all the variables.

Mike C

 

[Häakon]

with 1080 rgb you don't get raw, that is bigger for me than the cropping. I don't think the cropping will degrade the image significantly.
-A

That's interesting; I think we'll have to wait and see the results to determine that (and even then it will be subjective). I'd personally much rather have an oversampled image than a center slice - even with the RAW benefits - as I don't do a lot of VFX work and I prefer to light and balance as much as I can when I shoot as opposed to creating the entire visual feel in post. And that certainly isn't to say that an RGB image (especially a 10-bit, 4:4:4 one) can't be pushed around with good results after it's "in the can"). Benefits of oversampling are reduced noise (which can equate to increased sensitivity) and higher quality anti-aliasing, which can result in a far nicer picture. As Tom pointed out, a downsampled 2K image from a 4K Canon 5D shot will be far superior to cutting/cropping out a 2K image from the center of the 4K original.

Going with the center crop also means losing the 35mm DOF characteristics, the wider FOV, and potentially needing a completely different set of lenses. Again, not necessarily deal breakers - some will find this way of shooting to be preferable for what they do and others won't. But it is important to factor in all of the variables when making the decision - it's not just as simple as "RAW or RGB."

It also may come down completely to budget, time restraints, client demands, lens availability, and an array of other external factors.

 

[Steve Gibby]

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.)

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:

“We don't have to change anything... it was just a thought. But we don't have the space to do everything. We can leave the spec as it is OR we can get creative at the last minute. I don't really care either way. I'll shoot 4K at 24fps to CF or either 720P @ 120fps or 2K at 96fps to CF. My personal preference is 2K @ 96fps, but I'm just one customer. If the majority wants 720P @ 120fps... that's what we'll do. We can't do both. In hindsight, we would have put in a bigger FPGA (not available when we started) but then the price of the camera would be $4K more expensive. Choices... choices.”

Jim Jannard
7/30/07
RED User
http://www.reduser.net/forum/showthread.php?t=3450&page=7



In answer to this Shawn Nelson question: “Why is it one or the other? Why can't you enable both 720p120 and 2k96?” Jim said:

“FPGA space... imagine what we are giving compared to the competition. Think of the box size. Just think about it for a moment. There is a limit to what we can do. I know that seems an impossible concept since we are offering so much, but trust me... there is a limit.”

Jim Jannard
7/30/07
RED User
http://www.reduser.net/forum/showthread.php?t=3450&page=9



Then add into the mix this recent comment by Stuart English:

“You got it right Chris - relative to the video data rate audio is trivial.

The hours per mag discrepancy is just that the codec's AVERAGE and PEAK data rates are still being tweaked. In addition, some comments fall on the conversative side of that equation, some comments reflect the assumption its 27MB/s as per our IBC estimate.

Unlike tape decks that have a requirement of a fixed data rate, we have a lot of flexibility in using constant or variable bit rates and / or higher bit rates as may be most appropriate to the task at hand.

More later ...”

Stuart English
5/4/07
RED User
http://www.reduser.net/forum/showthread.php?t=2225


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…

 

[Poi Boy]

Thanks Gibby,
I think we need the big guy to chime in here.
Aloha
-A

 

[Häakon]

Haarkon Surely closing down your lenses does exactly the opposite of this. It increases your dof.

Mike C

Yes, of course. The rest of my post spoke correctly as I intended, I was just thinking of the stop numbers decreasing. Always mixing that up in my brain!

I fixed the original post.

Surely we are talking about the difference in dof between 35mm and 2/3rd inch chip cameras being an issue? ie the 'video' look we all hate? Or am I missing something here?

No, there are a few different methods of shooting with RED being discussed; in 4K mode, you shoot with the entire s35mm sensor. in 2K mode, you're shooting with a center crop of that sensor - they're referring to it as the "windowed" portion of the sensor. When you shoot 2K windowed, you can use 16mm lenses on the camera in order to preserve your FOV, but at the same time you expand the DOF. Some may not prefer to do this or find it acceptable.

The final option (right now anyway, that's what this topic is discussing) is to shoot with the full sensor but then shrink it to a 1080p frame in-camera. This means you are still shooting with your 35mm lenses and retaining that DOF, but your overall image size is smaller (it's much closer to that of the 2K windowed frame).

When you shoot in full 4K or the 2K "window," you record with RAW functionality. When you shoot 1080p in-camera, the footage becomes RGB, cutting some flexibility in post (but again, retaining the DOF characteristics and arguably getting a better image as it is an oversample from the full 4K frame). It's all about the different options the camera is offering, and we're just discussing which ones may work better than others in certain situations.