4:4:4 12-bit Uncompressed DVX100

[Charles Papert]

Yeah, my assessment of the DVX at 320 ASA was fairly casual and besides, the exposure curve of video vs film means that EI ratings are fairly meaningless. As was noted here, the underexposure characteristics are quite different, video will "see" a lot more into the shadows in the same way that it doesn't see into the highlights. It's just part of why I don't use a light meter with video unless I am pre-lighting a set without the camera in hand.

Also, the mode being used with the DVX would dictate the EI. Moving between different cine modes, you can easily note shifts in exposure.

This is not to dispute Barry and Jarred's findings, it's just interpretive. If the camera had a -3 db setting like the XL1, I would use that as much as I could to try to keep the noise down.

[Juan P. Pertierra]

Does anyone have an image of what the DVX looks like with the 35mm adapter on it? The current device occupies the bottom of the camera and is as big as the body of the camera itself. The probe cabling can be routed sideways along the bottom, but i'm not sure how long the cabling can be made without signal degradation.

Juan

[Juan P. Pertierra]

by the way Charles...

The A/D's in the DVX supports gains from -6dB to +42dB. Whether the camera actually uses the full range, i cannot tell from the schematic. The gain setting is set through a serial interface on each A/D so modifying this would be extremely tricky.

Juan

[Phil Rhodes]

Hi,

> If the camera had a -3 db setting like the XL1, I would use that
> as much as I could to try to keep the noise down.

Well, looking at these data captures, it would seem that "default" would be at least +6dB and possibly much more, considering how under they look. I presume this is probably so Panasonic can scream about the low light sensitivity in the ads.

Phil

[Charles Papert]

I'm inclined to agree with you, Phil.

Juan, check out our sponsor, ZGC, for a good picture of the DVX and Mini35.

I would think that a rear-mounted system would allow the camera to become a better handheld rig by itself (allowing for shoulder mounting) and still keep it compatible with the Mini35, etc. Although this would eliminate the rear viewfinder from use. Perhaps having the flexibility to mount both ways?

[Brent Douglas]

<<<-- Originally posted by Charles Papert : <<<-- Originally posted by Brent Douglas : II've been thinking that if you attach the JPWonderBox (ahem) to the bottom of the camera will this still work with the Mini 35 adapter? I'm not so sure how the adapter mounts cause I don't have one (or a DVX for that matter :( ) but they look like they mount on tthe bottom. I thought this would be important cause I recon if anyone is crazy enough to spend $6000US + lenses on the camera to get (from what i've heard) a marginally better picture and slightly shallower depth of field then every single one is going to be jumping on the bandwagon for this baby here.>>>

Brent, as one of the "crazies" who has spent the $10K it actually costs for a Mini35, I can tell you that the adaptor indeed mounts directly to the bottom of the DVX100a, so a breakout box would indeed need to be relocated for use with the Mini35. And while I'm at it, I can also tell you that the ability to use cine lenses introduces factors and possibilities unknown to most video users; focal lengths longer or wider than stock video lenses: better resolution characteristics and flare handling, not mention the world of specialized lenses such as swing-and-tilts, 2:1 anamorphic lenses, boroscopes, etc etc etc...and as far as "slightly shallower" depth of field, it's far more than slight. And yes, this particular crazy will probably jump on the bandwagon for this system once it becomes practical, so I'm watching from the sidelines and looking forward to seeing some frame grabs.
-->>>


Sorry Charles, I didn't mean to be offensive with the word crazy. The meaning is probably changed in context (Australia to US). Perhaps I should have used enthusiastic instead? I myself plan to get one (and a camera to go with it :P) when I can afford it which is why I mentioned it but I did also say I did not know that much about them. I probably should not have posted without researching what i was talking about more. I only did because no one else did and as a prospective buyer (one day) of both products I was hoping they would be compatible. I was not intending to slight the Mini35 or it's owners at all.


Brent

[Phil Rhodes]

Hi,

My concern is how easy this stuff is going to be to postproduce, especially in a more professional context (this may concern Mr. Papert as well.) I'd very much advocate at least a basic form of metadata, such as tagging each frame with a timecode. This is how digital effects are done with DPX sequences for feature production, and it would allow you to more or less easily conform your high-bandwidth uncompressed material to a cut based on either DV downconversions or tape that you also ran in the camera. Sound is also an issue.

Sure, there are ways to fiddle around all this stuff in FCP or Premiere, but I think at least a few bytes of metadata per frame would be useful. I imagine the problem would be obtaining it - I'm guessing that the DVX100 lacks an easily-read digital timecode output, where the 1394 output need not apply for "easily read."

Phil

[Bob Tasa]

Hi read through the entire thread with some excitement.
Like WOW you are one brave dude.
I am a software/hardware graphics person.
I was wondering if catagorize your device as
a Digial I/O interface that transfers image data to the
hard disk?
Also saw you mention that you could do this to other cameras
and I was wondering how since each camera uses slightly
different I/O interfaces dont they?

I find it MOST intresting. Were ever able to
eliminate the noise? I grabbed as many images as I could.
Sorry for all the questions just excited to see you push the
envelope.

Thanks,
Bob

[Juan P. Pertierra]

Phil,

Providing timecode is not a problem, the issue is how to provide it. We discussed using DPX files but a lot of people voted against it, just because TIFF seems to be more commonly supported.

Implementing DPX/Cineon files is not hard...i could include a feature to pick your format and have the timecode included with DPX files. However, i don't think programs like FCP could import them? This was a while ago, don't quite remember what conclusions we reached.

So far Shake seems to handle the raw files perfectly. FCP handles them as well. The only thing to remember is to set a compressed format for rendering while working on the clip, otherwise the files are too huge to handle.

Bob:
My device handles raw digital data, it works with any A/D in every camera i've encountered so far.

Juan

[Phil Rhodes]

Hi,

That's why I suggested the filename thing. Normally in film postproduction files are given a name based on the total frame count represented by the timecode.

01:14:03:21 is 106,701 frames from 00:00:00:00 at 24fps. An example filename might be myshot0106701.tif

You might choose to allow the user to define a prefix.

Because the largest valid timecode is 23:59:59:29 (the length of one day) and the largest number of frames per second in a standard motion picture format is 30, this number is always <2,592,000 and never more than seven digits.

Of course on NTSC DVX-100s this becomes a nightmare of trying to derive the same timecode from the 30-frame camera as will eventually be created by Final Cut once it's unwound the 3:2 pulldown, but I leave that one up to you!

DPX options would be good. I can see a camera assistant with a laptop wirelessly linked to the device tapping in the notes for each shot.

Phil

[Nick Hiltgen]

metadata seems to be a buzzword I've heard a lot these days, I agree with Phil's advice and think that if this camera wanted to be more useful to compositors and CGpost effects, it would be very useful to inculed lens numbers (f stops, focal length, focus setting etc. But I have no idea if that is possible. I wonder if it will be with the xl2's sdk? (I'm beginning to think that the canon SDK will end up being like the 3d lens...)

[Ben Syverson]

That data is already encoded on DV tape (at least on my GL1 -- it records at least the time of day, the gain setting, the Fstop, and the zoom level). So if you record DV along with RAW, you should be able to reclaim all of that data.

[Juan P. Pertierra]

Yeah, all the data is in DV tape as well, so as long as the tape is rolling the data can be used for the raw data.

The only issue here is that it would need user intervention in order to sync the raw and DV footage. There is a way around this, to sync the device record to the camera record, but it will take another probe.

For now i'm going to assume the user will pick which two frames correspond to each other. Once i'm done with the prototype I can add that feature. I'm sure there will still be some bugs to work out as well.

Juan

[Laurence Maher]

This is some CRAAAAAYAYYAYAYAYYYYYYYYYYYYY stuff man. All I request is that this magnificent thing end up being compatable with FCP . . . becasue I just got a mac system, so PLEEEAAASSSEEE.......

[Bob Tasa]

Juan,
As I cruised the internet looking for parts.
I gather that if you can get A/D output from a CCD you
deliver the digital data into a Raw RGB format.
I am a little fuzzy what you are sending it to.
A hard disk? Or a firewire stream?

Then I can use that data recorded to my hard disk
and with my computer?

I am sure you are busy if you can answer thats OK
Maybe someone else can answer in your place.

Just trying to fill in the gaps.
Why I am asking? I was thinking of looking for an OLD unwanted
SVHS camera and using your method to get the data into
a much more exceptable format.

Thanks,
Bob