Retrofit Panny DVX-100A to uncompressed HD?

[Ken Hodson]

Thanks for the detailed reply Jaun. A few questions if I may:
How do you get around the 4:3 of the DVX? Does one need an anamorphic adaptor, or does it end up being a HD 4:3 image?
What is the reason that you have chosen a Mac laptop only, why no PC? One last one, why so long to market? I have been following you guys periodically for quite a while, when are you going to ship, if not now, what is holding things up?

[Juan P. Pertierra]

Hello Ken,

To answer your questions:

1.)You are correct that the sensors on the DVX are approximately 4:3(actually they are 1.4:1). However since there is a significant increase in resolution, to get a wide image you can letterbox or use the anamorphic. Do note that because we are recording areas of the CCD that are normally cut off by the camera, the Anamorphic yields a 1.85:1 image, and 1.4:1 without it. The maximum frame size without up-rezzing is 1540x984.

It's very similar to shooting full-frame film. The Sculptor software has reticules similar to the video-assist on high-end film cameras, such that you can frame correctly even while recording the entire frame. This also allows the freedom to pan and scan later.

2.)The reason why we chose the mac is because the Powerbook and Mac Mini can do something that few(if any) PC's can do, and that is sustain the required ~30MB/sec over USB2 while being portable and/or tiny package. PC's have a very wide variety of hardware configurations, and even if there are (just) now a few machines that can do this over USB, we would need to write low-level drivers for each machine, and test each PC model independently. With the mac, there are only a few models and implementation was a lot simpler since there is no low-level drivers required to get the maximum performance out of the hardware. Plus, for about $400 you can buy a mac-mini that can do the job.

I know that in the consumer world "common-knowledge" is that USB2 can do 480Mbps, but that is not accurate as far as transfer rates. The common USB2 card you can buy now days does about 30MByte/sec max. Many do less.

3.)If you were following our original discussion here on DVinfo, then yes, it has been a long time. The main reason is that this really only became a commerical endeavour about a year ago. Given that, we had our first beta units out in about 6-7 months from the beginning of product design and development.

Considering that I single-handedly did all the design and development of both the hardware and software that's not too bad is it? :)

We are currently taking pre-orders for our first production batch which just arrived. Sales are scheduled to begin early January.

Hope this helps, let me know if you have any other questions.
Juan

[Tomas Chinchilla]

...This is out of the DVX arena but bare with me....

Considering the Cost of a new/used DVX out there and the cost of a new/used FX1, would you consider doing something similar for the FX1?

I don't think is far fetched but then again you are definetly smarter than most of us in terms I would not even dream of making something like you did and wouldn't know how to start.

Given the amazing quality of the FX1/Z1, could you in theory be able to tap into the system and grab the raw image data to be able to record the shot in 24p/30p on the laptop? somehow I remember seeing an article stating that the FX1 recorded progressive and interlaced the image, I'll try to find the post.

I am dreaming here?

Please don't shoot me guys, its just a question.

[Juan P. Pertierra]

Hello Tomas,

The concept applies to any digital video camera, however it has to be re-designed based on sensor size, etc.

That said, it is very unlikely that we will do a version for the Sony Z1/FX1 for several reasons.

First, the DVX100+Andromeda already yields more resolution and a lot more dynamic range than the Z1/FX1 in any CineFrame mode.

Second, the Sony has interlaced chips, and we've had almost 0 requests for uncompressed interlaced video. The grand mayority of the input we have received is for Uncompressed 24P which can be easily molded for a particular look without having artifacts, decimation or low dynamic range in the way of filmic color timing and fx work.

Hope this helps,
Juan

[Ken Hodson]

Any particular reason why only USB2 and not firewire? I am still a little puzzled about the claims of Apple powerbooks having (more usb bandwidth) is that relevant to only certain PC chipsets, or all? And if so is the limitation the same with firewire? What about firewire 800?
I am also puzzled by the claims of such increased latitude from the SD cam (DVX100a) as I just do not see that dramatic an increase in latitude over the top HDV cams. If the advantages were that marked, why didn't HDV cam makers simply use their SD cams and pixel shift as you have done? Sorry for all the questions but so many things are puzzling to me in regards to this.

[Juan P. Pertierra]

Hello Ken!

There are several reasons why we chose USB. First of all, when we started talking to people and showing them the prototypes, one of them was a box mounted under the camera which would have a firewire interface. However, this box design was met with rejection because among other things, it prevented some accessories from being mounted(such as some 35mm adapters), required it's own battery, and would be overall more expensive to the costumer and for us to produce. Every single person we talked to wanted to keep the ergonomics of the camera intact, and wanted just a port added that you could connect to if you wanted uncompressed. They also wanted the lowest price possible and little if no effect on the battery life of the camera.

USB allowed all this. The board is small enough to fit inside the camera, and be invisible except for the extra port. The power is taken from the USB host, so the battery life(as well as all other camera functions) are unaffected. You can mount every single accessory in the same way you would with a regular DVX. And it is a lot cheaper to the end user than an external device with it's own battery power and firewire interface. Another point largely overlooked is that using firewire would require users to have a fast internal drive, as USB drives wouldn't be fast enough. Using a cheap external drive is a big advantage. A 100GB hard disk which can be had for under $200 will store about 1 hour of Uncompressed 4:4:4 footage. Compare this to a $2k P2 card holding 8 minutes.

About the latitude, you don't have to take my word for it. We have done quantitative tests using a backlit ND chart, using an Andromeda DVX-100A. The two frames are the exact same frame(same moment in time), but one is captured at the A/D stage with Andromeda, and the other is what the tape records after the camera processes the A/D data. We have shown these results to knowledgeable people such as Adam Wilt and Barry Green, and they both agree with our assessment of about 2-2.5 stop gain on the highlights. The charts are here:

http://www.reel-stream.com/gallery_t...gallery_type=2

The light coming through each step was carefully measured with a light meter. The Andromeda clearly conserves considerably more dynamic range than the DV output captures.

As far as the HD/HDV cams, the HVX has been reported by Panasonic to have been tested at about 7 stops which is about the same latitude as the DV output from the DVX. The XL-H1 hasn't been tested AFAIK, but everybody can see from the footage posted on here that it clearly has a lot less dynamic range than the DVX or HVX, putting it conservatively at 6 stops, probably less. Same thing goes for the JVC, although it seems to lie somewhere between the DVX and Canon.

If the advantages were that marked, why didn't HDV cam makers simply use their SD cams and pixel shift as you have done?

Remember that I said pixel-shift has advantages and disadvantages, not advantages across the board. A possible reason why camera companies would go for higher-pixel count sensors and sacrifice other performance aspects is simple:

PIXEL COUNTS SELL

Try a search in all the forums and see how many people are talking about resolution/pixel counts and how many mention, say, dynamic range. You'll see that when asked what they want from a new camera, they immediately say 2K! 4K! If you ask me, give me 16+ stops latitude uncompressed, at 720P and as much color precision and frame speed as possible. The studies done on cinema resolution show that at the best, a standard cinematic print has about 600-800 equivalent lines of vertical resolution. We've been exceeding film for a LONG time as far as resolution goes. All the current and vapor camera designs seem to completely miss these other aspects that nobody is addressing, except Panavision.

And then people wonder why it still looks like video. It's not impossible to do. Everybody seems to be just barking off the wrong tree. :)

BTW, it is likely that Panasonic is using pixel-shift in a similar way to produce 1080P on the HVX. They are also refusing to release pixel counts for the CCD's. I think this illustrates my point.

Hope this helps,
Juan

[Kevin Shaw]

Juan: any predictions on the dynamic range for video from the HD-SDI outputs on the Canon camera? If this data is coming straight off the sensors, shouldn't it yield roughly the same result as tapping the sensor on the DVX?

[Juan P. Pertierra]

SDI and HD-SDI is formatted digital video. This means that it goes through all the in-camera processing except the final HDV compression layer that would normally be put to tape. The output from the HD-SDI port is not raw, so it exhibits decimation along with all the other byproducts of the in-camera processing except compression. The difference with raw output is that it is RGB direct from the sensors(A/D) without any processing done to it whatsoever. It is the most pristine data available inside the camera.

I think it's a great step forward for them to add an HD-SDI output, unfortunately the camera exhibits such limited dynamic range. Even if we did tap the sensors on the XL-H1, I doubt it would yield nearly as much dynamic range as the sensors on the DVX. The sensor element area is so small.

BTW, Area 51???

Cheers,
Juan

[Ken Hodson]

Hi Juan. Thanks for taking the time to answer questions. Good luck with the release.
Ken

[John Benton]

Juan - thanks for all your hard work -
I am torn - it seems your solution gives a higher res/ less artifacting solution than the HVX -
Is there any possibility/ advantage to making your products compatable with an HVX
?
Thanks,
J

[Juan P. Pertierra]

Hello John,

I've been hearing that a lot lately :)

That's a hard question to answer. It might seem like making an Andromeda for the HVX would be a.)as simple as the DVX and b.)yield advantages across the board.

The truth is that, assuming we want to capture up to 60 uncompressed frames a second, the bandwidth is such that the design of the device would have to be completely different, since the bandwidth is not manageable with existing standards such as firewire. We would need to build something like a portable RAID array connected to a box under the camera, which gets complicated.

Also, because the pixel elements on the HVX are smaller, it is very possible that we might get worse dynamic range and sensitivity with the HVX chips.

However, it is too early to say, we will have a better projection when we get a chance to work on one.

It is really up in the air if we will get an advantage in resolution:

http://forum.reel-stream.com/viewtopic.php?t=363

Anybody know why we are in the Area51 section?

Cheers,
Juan

[John Benton]

thanks, Juan for your quick response -
if I was already a DVX owner, I wouldn't hesitate

I wish we could compare the Andromeda & HVX200.
The charts are interesting it's hard to copare Tiff's & Jpegs - the Sony looks better than the HVX by far with the JVC coming in second

[Juan P. Pertierra]

John,

If you are interested in seeing how the image format affects it, just convert the tif file to jpg in photoshop. Tif is lossless so it will be the same as if it was exported directly from Sculptor.

When we get the chance we'll do a side-by-side with the HVX. From the specs we know however, Andromeda on the DVX100 gets wider dynamic range(9.5 stops), more resolution, no artifacts, no decimation, higher color precision, etc.

Because the data is recorded direct from the A/D converters uncompressed, the filmmaker is free to color-correct the images and give them any desired look without destroying the footage by enhancing artifacts.

Cheers,
Juan

[Ken Hodson]

It sounds very promising Juan. How does the DVX lens hold us back with your setup? It must not in at least some respect as it was not designed for the specs your eqipment provides. Both Canon and JVC have been criticised for their HD lens (I personally disagree given cost/performance ratio (esp. the JVC at its price point)) how does the SD Panna lens hold up under zoom and or shallow depth of focus situations? How much CA? How does the sharpness hold up across the image? Any other problems you have noticed?

[Chris Hurd]

Hmm, this really doesn't belong in Area 51.

Should I file it under HD Acquisition, or Alternative Imaging Methods?