1080p Camera Design

[Mike Metken]

Hey guys,

I have been following this and couple other boards for last couple weeks. It is a lot of information toabsorb. It is all very fascinating stuff. Here are my opinions:

You must follow some proven techniques and take into consideration what was tried and what works. Also there is no need to reinvent the wheel.

1. On digital cinema production you, as a rule, use 1. a viewfinder or a small LCD and 2. a full resolution monitor. You have lights and whatever that you neet to use outdoors even during the day. You drag along a lot of stuff. You should considering on including a computer. Maybe initially it would be a large one but as soon as some small ones that are powerful enough become available, the concept would stay the same, only the computer would change.

1a. You should consider what is out there and how it fits into the budget. And you need to consider price/performance ratio. I started a thread on use of available equipment and it seems that everyone wanted to keep the system cost under $10,000.

1b. You need NLE. But the NLE can also double as a recording device and it can feed your monitor.

1c. How much quality do you need? As everyone, including me, is very cost consceous, would the same quality satisfy you as satisfies major movie studios? The same quality as in Rodriguez' films Spy Kids 2 and Once Upon A Time In Mexico? Those films were recorded with $100,000 camera that records 1440x1080/24p at 110 Mbps, 8 bit, 3:1:1, with 4.5:1 compression. Varicam that costs $60K and is used for indie film production compresses 6.5:1.

1d. You must realize that 10 bit systems are expensive, that uncompressed is very expensive, and that Mac is generally more expensive than PC.

1e. I would suggest to record on PC, uncompressed, then transcode the footage to Aspect HD in the high quality mode. That will be the codec that you will store the images, codec that you will use on the same computer for editing, and for making your final cut. Maybe the camera manufacturer, or some computer outfit could arrange OEM pricing on the Aspect HD/Premiere package.

1f. What quality will you get? 8 bit, 6:1 compression, 4:2:2, 1440x1080p. Overall the same or beter quality than CineAlta $100K camcorder.

1g. That leaves the camera to be the limiting factor to quality. Camera with one AltaSans 1080p 60Hz chip will output effective 1440x1080 pixels. So you will get the same potential quality as with the $100K camera, considering the image is well adjustable on the low cost one.

1h. The camera LCD can be monochrome; that takes care of the color correction problem. The Monitor should be at least the Sony 16x10 aspect ratio large CRT monitor that sells on U Bid refurbished for a few hundred dollars, when they have them. It has 1920 horizontal pixels. It is large and heavy, but it is a must. Once you use a monitor like this, you see that adding a computer is nothing. But to get accurate color, you would need to use special, a lot more expensive broadcast monitors.

2. There is no need to design a local storage with some processor if there may asoon be a mass manufactured solution soon that will make the design obsolete. I would instead use what is available.

3. You need local camera controls. You need to control the basic functions locally. You need at least tungsten and daylight color corection setting. Auto white balance would be very desirable. You can then zoom onto a white or gray object to set the white balance. Or you can use a white trnslucent cover on the camera and aim it at the loght. You need shutter control, manual and auto exposure control. You need to modify to exposure curve to give it more cinema gamma. You should have a switchable gamma curve with settings for knee control at the top to prevent blowing highlights, etc.

4. You need to take care of defective pixels. If you get a name brand camera and you fly in a plane with it and cosmic rays hit the CCD and you get defective pixels, or if they just go dead, the standard manufacturers has a solution for that. This needs to be addressed. Otherwise the low cost cameras have no long term value, because pixels do go bad.

5. You only need one sensor. But it needs to be the best avilable.

6. Concentrate on design of the camera. The system needs to be upgradable and modular. Maybe today $4K industrial camera is good enough. But there is also a Sony HDC-X300 camera that is 3-chip 1080p and costs $15K. There was no such thing until recently. If you wanted 1080p you needed to use $90K studio camera. So maybe in a year another manufacturer will come out with a similar camera as the Sony, but with one chip, for $5K. What do these major manufacturer cameras have in common? HD SDI interface. HD SDI PC cards drop in price in half about every 6 months. Now you can buy one for about $1K. A year from now they mey cost couple hundred dollars. The coax can be 200' long. So we should go by the video industry standards and use HD SDI, not some non-standard interface. It will make the camera also sellable to the pro market. The Red Lake camera is nice, has a control box with adjustments, etc., but no standard industry interface. You know what that means? No video, broadcast or digital cinema sales.

7. Come out with some kind of 35 mm adapter and have it mass manufactured. Don't each of you guys make your own. Someone should come out with a standard design; then we'll find some company in the Far East to mass manufacture it. Or we can start calling them now. They can carry on the design beter than we. You need to keep the distance from the GG to the lens constant. I think that vibrating design would work the best.

8. Use C mount lenses for wide angle and 35 mm for longer focal lengths. There are plenty of high definition, high contrast, megapixel C mount lenses available, including macro lenses, that could be used in the adapter. For longer than standard focal length, 35 mm SLR lenses will be more cost effective and will be better for do follow focus. 35 mm to C mout adapters are cheap..

9. You need to look at the cost of a whole system and make sure that it will not be obsolete soon. I started a thread on available low cost HD solutions. I listed there system costs. Even if you don't use local hard disc array and record to the NLE PC, you can't keep the total price as low as many here imagine. Check that thread. There are some comments by some movie people who shoot 16 and 35 mm film stock, who talk on a differnt wavelength. Just realize that.

10. You need to know at where is the pro and prosumer HD market heading to make sure that you don't make today something that will become obsolete tomorrow. I say concentrate on the best one 2/3" camera, 1080/<30p, with HD SDI interface and C-mount. Forget anything else for now on. If you can create a plug and play device, your sales will be high. If you create a non-standard solution, realize that the majors will be creating quality low end HD products soon. Their not so good HD product that will be easy to use will make your a lot better non-standard product gather dust on a shelf.

Mike

[Mike Metken]

On a digital cinema production you use normally the camera output to feed a monitor. So the camera is connected with a cable to a large and heavy monitor which needs to be powered. Feeding the camera to the computer and from the computer to a monitor does not make the camera any less versatile/free.

Capability to record 2 cameras to the computer simultaneously would be very desirable. You can record a two camera shoot or you could set up the cameras side by side and create a 3D movie.

[Obin Olson]

You don't want or need white balance, all that does is mess with your image BEFORE post...bad idea.... you need to record RAW just like any professional photographer knows about his digital still camera.. never mess with your image BEFORE post UNLESS you want to stay with what you shoot as-is onset with some bad lighting on your preview screen...this is a new world, in this world you need RAW as far into the process as you can drag it

[Mike Metken]

Obin,

Sorry, I disagree. Technically it does not make any difference if you do the correction first or later. Why do you think that all the cameras, except for rare exceptions, correct color before recording? Because that is what the director and DP want. It makes the work a lot easier.

You mean that you don't mind watching some uncorrected color on a monitor? That makes production very difficult. You look on the monitor for color composition problems, among other things, unless your film is B/W.

To make the camera a profitable sellable product, the manufacturer must give the buyer what he wants.

Mike

[Obin Olson]

Do you white balance film? no.
Why would you white balance digital film?

You don't understand how it works at the RAW level...Have you ever used a professional Digital SLR camera? If you shoot in RAW you have NO white balance it's something you "set" in post and you can change in post ..I understand why you say this, so would I a few months ago but trust me what I am saying is right...RAW captures LIGHT and only light in the Red Green and Blue spectrum, that is ALL it does NO image processing happens until AFTER you transform the DATA to an IMAGE

White balance is for cameras that record an image and make decisions about what to keep from it and what to throw away to compress it down to a small size for tape recording etc....


Not to say that you could white with a raw camera for PREVIEW on set..that would be a good thing but you want RAW recorded images to deal with the BEST quality you can get for your final product.

HTH

[Obin Olson]

BTW Mike, I plan on making a 1080P version...it will take alot more disk speed and space so I will start with the 1280x720 for now..after all that is the res of the Panasonic varicam and a standard for HDTV. I would think 1280x720 is enough to start with as a "test" project at 10bit 4:4:4 RAW

[Rob Lohman]

Obin: actually you do white balance film. Only in that case you
choose between indoor stock or outdoor film stock. This is
already "balanced" to a color temperature. All the lighting etc.
is matched to that so you will know what you get.

Personally I would want to color balance at least the viewfinder
picture but probably the RAW image as well. As you indicate it
does not matter. It is simply shifting colors around which you can
always undo without any loss if you want.

If you can at least balance (the viewfinder) to some level you
can see how well colors look in relation to each-other etc.

But that can certainly be an option. If you/we/whomever does
decide to add (white) balance you can also make a setting that
does nothing to get the original picture as it is coming off the
chip.

Personally I'm not sure why everyone wants and is thinking
so much about 1080p. It will be a really tough job to get 720p
to work reliably and in a camera system together with a file
format that an NLE can actually edit. Let's focus on that first
and then see if 1080p is doable. I'd much rather have good
working and affordable 720p variable frame rate recording than
1080p with problems and heavy price tag.

[Mike Metken]

DP is normally using incident light meter, narrow angle spot light meter and a color temperature meter. You color balance film. With video it is less critical because you can change it easier in post. Still you color balance it during production.

The viewfinder image is not enough. You need a large full resolution monitor too, and it should be color balanced.

Why would not 1080p be doable? The chips are available; inexpensive megapixel HD lenses are available. You can compress it real time on a PC so storage cost is not high.

Mike

[Rob Lohman]

As you say you either compress it or you don't. If you do not
compress it (like most people here want) then you are going to
need massive amounts of storage and speed (more important)
to store it all (which eats a lot of power as well).

I highly doubt you can effectively compress a 1920x1080 10+
bit image running at 24 - 48 fps in realtime with stuff we can
afford.

[Mike Metken]

Rob,

I spent a lot of time communicating on this with Boxx Technologies. Also David Newman of the HDV NLE forum has all the info and could be extremely helpful. We should get him involved.

CineForm used Prospect HD to compress Viper real time at NAB.

Check out Prospect HD, Aspect HD, Premiere, Boxx Technology RT systems, Boxx HDV systems, CineForm. Some interesting info.

Prospect HD is 10 bit, Aspect HD is a light version, 8 bit.

Prospect HD requires dual Opteron processors.

The results are amazing.

What this means is that we could have a $5K or so PC with Aspect HD, feed the camera into it, hook up the monitor, record uncompressed and then encode with Aspect HD for storage and NLE. With Prospect HD you can do it real time via HD SDI input. With Aspect HD you could do it real time too if you could feed the computer the signal Aspect HD works with.

I think that this would be a nice solution. You will drag a computer with Aspect HD to the set; 2 TB storage will give you some 30 hrs capacity. The quality will be about equal or better than if recorded on Sony F900.

If the manufacturer could come out with a camera that has 1440x1080p, 4:2:2, 8 bit output, you can use an inexpensive PC to compress it real time 6:1 in a highly transparent codec. I think that this is what we should concentrate on first.

As to HDV quality. Wno needs 19 Mbps HD. Our compressed solution will have many times bigger bit stream.

I sincerely believe that the Aspect HD is the way to go now. It is here now. The next step could be the internal storage.

Mike

[Mike Metken]

There is another real time compression option. If you use Mac with FCP HD, you can compress real time in JPEG or something; I'm not sure. If you record 720p, after you record it, the computer can encode real tome in DVCPRO-HD. That is about 6.5:1 compression, same as Varicam.

[Rob Scott]

<<<-- Originally posted by Rob Lohman :
I highly doubt you can effectively compress a 1920x1080 10+
bit image running at 24 - 48 fps in realtime with stuff we can
afford. -->>>

That's correct. It would almost certainly take a custom hardware solution get high quality at real time. It's always a tradeoff between performance (speed) and quality. So by doing it offline, you can get far better quality with for less cost (hardware and development costs) ... at the expense of time.

This project simply is not going to be appropriate for those who have more money than time; those people should buy (or rent) the pro equipment.

For the rest of us who have a bit more time than money (or can at least have enough time to let the thing process overnight), a non-real-time solution may be very cost effective.

[Mike Metken]

Rob,

FCP HD and Aspect HD/Premiere cost $1K each. You use them for editing anyway. There is no serious additional cost for using the NLE PC also for recording, especially if they will do real time compreasion. If they do not, fine. You can still use them for acquisition and compress overnight, like you said. But this acquisition option is available now.

Mike

[Rob Scott]

<<<-- Originally posted by Mike Metken : FCP HD and Aspect HD/Premiere cost $1K each. You use them for editing anyway. -->>>

Yes, I was just looking at Aspect HD -- it looks very promising as a space-efficient codec to compress to. I think we'll definitely need to support it in some way. Initially, this probably means offline compression, but if it's efficient enough to use in real-time, then why not? (As long as can also get good color-correction, gamma, etc. in real-time. We don't want to lose our latitude by reducing to a poor 8-bit image.)

[Mike Metken]

Rob,

Good. I'm glad I got my point accross. My problem is that computers don't like me, and I don't like them. Can you guys work with David Newman of CineForm on this issue. It is beyond my head.

I am really excited about this. What also needs to be investigated is which NLEs computers will allow you to record and display at the same time. Otherwise we'll need another output on the camera for a monitor. The viewfinder is not enough. And it needs to be in proper colors. Otherwise, I would not want it.

Mike