4:4:4 12-bit Uncompressed DVX100

[Juan P. Pertierra]

There's probably going to be a remarkable amount of color precision in those missing 6-bits. Right now there are 1024 levels per channel. When the lower 2-bits/channel are available there will be 4096 levels...technically there should be (4096 * 3) colors available which is a lot of color, but i think RGB has a lot of overlapping information such that the actual number is less.

However, i'm not sure if there will be that much more latitude in the lower bits, just because they are low-end bits. For example, right now adding the two bits will only add a value of 3 to the maximum number of levels that can be represented per channel...however these lower bits add 4 intermediate levels between every two levels available right now in the 10-bit RGB, which is a very considerable amount of additional precision.

I never expected the raw output to have more latitude than the DV output, but I stand corrected! I guess the people at Panasonic had to do some incredible compromises just to make it look half decent on DV.

It's like buying a ferrari with the hand brake permanently set.

[Milosz Krzyzaniak]

Jason:

I would wonder if you are right. By >>overexposing<< I was refering to the DV footage, but in terms of RAW image - opening some f-stops would turn the image from >>underexposed<< to >>properly exposed<<.

There is some thing that tells me that you don't understand the thing at all: you are talking of exposing to zebra - but the zebra's standard DV 100% of exposure is actually at the level of about 30 percent tonal in the RAW image. Grabbing RAW, and adjusting exposure to this standard DV 100% of zebra would be wasting 70% of RAW capacity. Actually if you talk about zebra, we would rather need a sort of "RAW ZEBRA", that could tell us when the whites are clipping not in DV range, but in RAW range that we work on.

Of course, I'm kidding with this "RAW ZEBRA". It would be just enough to - firstly - set the exposure to the standard DV zebra 100% and then lift the exposure by a factor of 1 or 2 f-stops, how much this should be - that would tests of Mr Juan show.

And why to expose with more light?

1. More information in shadows (while not clipping whites!!! - so no loss of information in highlites)
2. LESS NOISE IN SHADOWS.

Of course there is always a question if those upper 70% space of exposure in RAW is sort of the same quality as the lower 30% in which the camera exposes normally to DV. It could turn out that this upper range is somewhat inferior to the "normal", I don't know - not linear or something, but right now no one of us knows this until Juan makes some test (preferably with a person's face, or maybe showing a sunny street would be a good idea anyway). If it is not inferior, than I'm sure on my point.


Juan:

And this is frustrating that buying better model you overpay just for the brake to be turned off:)

[Justin Burris]

When I follow Juan's links to the DV and Raw files, I can get them in my internet browser, but I can't seem to find a way to pull them out into any other program to play with them. It loads in Quicktime, and when I click on the image, it just gives me quicktime options.
Is there a trick to getting them to check them out?

I feel like there is probably a really easy answer to this, and I am just overlooking it. Thanks for the help.

[Milosz Krzyzaniak]

Try to download the file with a download application as GetRight or Dowload Accelerator.

[Rob Lohman]

I've activated the links so you can right-click on them and then
download to your harddisk for opening in other applications.

Juan: to do this yourself in the future take a look at this page
in our forum guide. It explains how to add url tags around your
links so they get hyperlinked.

[Juan P. Pertierra]

Thanks Rob! I meant to do it but totally forgot, will do it next time.

I'm in the process of moving the camera right now...

[Juan P. Pertierra]

I managed to move the entire thing, computer and all to my sliding door window, but i got done pretty late last night...it's a nice day out today so i should have a clip soon.

I'm also taking a stab at reseating the probe to see if the speckles are related to the connections. As far as i can tell there are two bits one in the green an another in the red which somewhat randomly goes to zero and sets the pixels to a dark color...

if someone can take a stab at looking at the speckles and seeing if they agree, and which bits are causing the problem, i'd appreciate it just to have some other insight. I checked them by looking at adjacent pixel values around the speckles and then seeing what was missing from the speckled value...think about it in binary numbers, and if a single bit is causing the problem all over an area....

Thanks
Juan

[Juan P. Pertierra]

Ok, i have a couple of clips. Not much just a car driving by my house and a friend of mine waving. I also have DV counterparts. Like the previous frames, the difference in latitude is obvious. In one shot, the sky, concrete road, and several other areas of the scene are just straight out white on the DV footage, while nothing clips in the RAW footage, and even captures the different tones in the sky.

However, a 3 second clip is well over 100MB, and I do not have the web space. What does everyone suggest? Also, i have a stream of frames which i can use as an animation in Shake, or FCP but does anyone have any suggestions as to what video format to use? The best I can do with what I have is 4:2:2 uncompressed 10-bit MOV i think.

I've got all 30-bits, but the speckled noise is still there...my main task now is to try and figure out where it is coming from.

Juan

[Stephen van Vuuren]

I've got space but no bandwith left because of my test clips. I know DVInfo does or I could take donations for extra bandwith if they don't have space.

[Rodger Marjama]

I may have about 4~5 gb bandwidth a day to spare for a while. Let me know if you need it and I can setup an ftp account for you.

-Rodger

[Juan P. Pertierra]

I have posted 30-bit RAW and DV versions of the same frame, from a clip i recorded today. Unfortunately, the speckles affected nearly all the fine details in the RAW capture, but nevertheless it is a good example of the added latitude.

The color is waaaaay of(can you guess from the red sky?), but this is because I am posting the unaltered output from the CCD's...if you want to take a crack at doing color correction please do so and email me the result so i can post it.

http://expert.cc.purdue.edu/~pertierr/cap2_DV.tif

http://expert.cc.purdue.edu/~pertierr/cap2_RAW.tif

I am hard at work now trying to figure out where this video-pox is coming from. :)

[Peter Plevritis]

Juan,

The R,G,B channels in the RAW data don't seem to be lining up.

In Shake view the separate channels of both the DV and the RAW and you can see the shifting in the RAW.

That would explain the colored edge fringing.

Shooting a b&w chart would help figure out the pixel shifting.

Great work. I monitor this thread very closely.

Pete

[Juan P. Pertierra]

That's right! Thanks for pointing it out.

It's tricky to find what is the correct alignment, so i decided to post the photoshop file for that frame, with the R,G,B as separate layers. If any of you can take a look and let me know what you think is the correct alignment. I beleive the infamous pink line on the left of the DVX output may be just an artifact of shifting the R,G,B frames for alignment, so it might be a hint as to what is correct. This psd file works well also if any of you want to try to color correct this thing:

http://expert.cc.purdue.edu/~pertierr/cap2_RAW.psd

[Rob Lohman]

I'm assuming the color issues is due to the camera not doing the
whitebalancing to after you captured the RAW footage? If so,
some on the fly color shifting (something else than correcting)
might be interesting to have...

[Rob Lohman]

I did a little manual color balancing in Vegas (somehow it doesn't
seem to have a whitebalance filter and neither does Paintshop
Pro, weird!) and came up with the following:

manual white balanced cap2_RAW