Ben I love your plugin! but in the end after all is said and done I got a much better key from y/c capture direct to disk then I ever could from your plugin....and I really really tried to make yours work...for many shots your plugin is great but some the y/c capture just worked better...you don't have to challenge anyone, I KNOW dv is "better" but sometimes it's keys are not...

Ben, y/c out has no chroma blockies like dv does..that is the ONLY reason I could pull a better matte...i'ts not that y/c suppresses them,,they just dont exist period...i talked with Panasonic and they also told me that y/c does NOT hit dv compression on the way out... Peter y/c sucks Juan's 4:4:4 digital out is MUCH MUCH better then Y/c.....

Since all the Svideo capture is doing is massively smearing the chroma, one thing to try when dvmatte is not working out is increasing the chroma blur. You should never see the "blockiness" of MiniDV chroma after dvmatte is done with it. Besides blurrier chroma channels, there are really no other reasons why keying Svideo would work better than MiniDV.

Especially if you're using dvmatte pro, you should have no trouble getting a better key from MiniDV than with Svideo footage....

Sorry, I know this is OT -- I'll shut up about y/c capture now. :)

- ben

Move this thread to Alternative Imaging?
 

There's a new forum Chris has but up (Alternative Imaging) and I'm wondering if that might be a better home for this thread for several reasons:

(1) Due to it's popularity and longevity, most DVX100 users here are quite familiar with it. Juan could post results later.

(2) The technology he's developing could apply to any camera (e.g. XL1s with mini35, JVC HDV etc).

(3) Input from other "alternative imagers" might enhance the thread

What does everyone (esp. Juan) think?

Stephen,

I think it's a good idea, either way I will post results in this forum later.

Update:

That last complete frame i posted had much less precision than 9-bits, at least in the blue and green channels...you can tell from the color shades on my hand that it's pretty decimated. The partial frame i posted before had a bit more precision.

Today I am working on fixing this problem to get the full 10-bits out of each channel, it's only a physical contact problem, but these are pins less than 0.5mm in width, so it takes some time to work with them.

The continous capture is working, so this is the only hurdle to getting the full quality video my capture card can handle. A second capture card would allow me to capture the full 12-bits per channel, but it costs ~$700 so this will have to do for now....

Will update again tonight.

Juan

Got really quiet suddenly. Did I miss something and this topic was moved?

Looking forward to seeing the continuous capture.

Run into any problems?

Pete

I just moved it to it's new home here.

I don't understand. Is there any new location of this thread?

Peter:

I've reset the chip probe and will hook it all up again tonight to see if I got all 30 bits this time. I've been slowed down a bit by a nasty toothache...

Milosz:
This thread is now in the Alternative Imaging Methods forum, it used to be in the DVX100 forum.

Juan

Milosz: yes, the thread was moved to another forum. It is now
in "Alternative Imagine Methods". I think it was in the Film Look
forum.

The thread identifier hasn't changed. So if you have the thread
bookmarked for example or have notifications on the thread,
those will still be in place and working! So no problems.

juan, any news? any pictures? movies?


filip

Sorry for the lack of updates, i have been working on a better solution to the probing problem, and i'm almost done with it...now it's just snap-and-go, and hopefully all intermittent bit connections will be fixed.

I have also been working simultaneously on my software which now spits out 16-bit/channel RGB individual frames in a new directory, takes care of flipping over the blue channel, etc.

more to come soon.

Juan

Update...
 

Allright! So after much time experimenting i designed a new method of easily probing the pins. The good news is that i'm pretty sure I am getting all 30 bits(10-bit RGB). The not so good news is that there is still some noise, which must either be related to the bad cables I am using, or somehow related to the missing lower bits. However, i beleive it has less noise than the images i've posted so far.

Right now the whole thing sits in the same place, so if you'd like to see some boring frames, let me know what you'd like to see(coke can, magazine cover, etc.) as well as lighting.

Tomorrow i'm going to finally move it all to the window and take a decent clip of a car driving by. If it's sunny, it's bound to be a good test, there's plenty of color around. Right now because of my setup i don't have control over exposure(controller disconnected) so everything is at full open, hopefully the ND's will do the trick.

Another note:
While working on the camera I was amazed once again at how much space there is behind each CCD chip, and I realized that an incredibly easy and useful mod would be to mount thermoelectric coolers on each chip! These are only about $15 a piece, and I can adhere one to each chip, run them off a battery. This should have a great effect on the S/N ratio, it's a similar technique to what is used in astrophotography, to reduce the thermal noise to a minimum...i'm not even sure why some manufacturer hasn't included it.

Juan

Interesting!

Ok, let me see how to explain this...

While looking through the viewfinder in my current scene, there are clearly areas in the scene which are overexposed(allwhite).

Now, i would expect this to be the point at which the CCD's clip, and like so i would expect to get white or close to white in those areas in the RAW feed...

HOWEVER, i am getting values in those areas as if the A/D's actually topped off the 12-bit but instead of giving me the max 12-bit value(i.e.white), it's going around and starting over at the bottom, giving me a dark value, but which really reflects what is in that white area! I'm not sure what is going on, but the way it looks now i think i can use this to pull detail out of the areas that clip out in standard DV footage...

Juan

glad to hear from you again! are you talking about Peltier coolers? how much would that effect the s/n do you think?

keep at it..I am sure you will figure it out....I would love to see a pic or 2 of your setup on the test probe and how it connects to the chips...not that I would ever do it but just to see how it works ;)

<<<-- Originally posted by Juan P. Pertierra : I'm not sure what is going on, but the way it looks now i think i can use this to pull detail out of the areas that clip out in standard DV footage...

Juan -->>>

Great. Expecting to outfit at least 3 XL's with your mod (whenever finished), and the only remaining problem i have with emulating/duplicating film quality, is the lack of latitude in exposude on digital.. so if you can improve that, all the better!

So, Juan? It seems that my prediction was right? The same as in my friend's Canon D300 the RAWs give more dinamic than standard pictures. And I'll tell you I think this would be the biggest advantage of RAWs among all (4:4:4, no compression).

Suggestion on how to prepare the test situation to shoot. You dont need to move your dvx to the window to obtain some movement, you just may use your hand to move something. Put a doll or something in front of the camera with a lot of colorful things. And the most importatnt: light it with much contrast: put a light to the side of the scene and light to overexposion: we would like to see what is the behaviour of this RAW thing in such conditions.

Just rememer to film not a planar thing (wall, book) but a real 3D something that could give shadows and so on.

Good luck.

Adam: what makes you think this will work with an XL1S? Juan
is building this with a DVX100 as you can see from the thread
title. I would not assume (automatically) that:

1) the XL1S has 12 bit stuff in it (I don't know it if has)

2) someone knows how to get to it

3) someone has tested whether it will work

4) someone will ever do any of the previous points

etc. A better question might be to ask whether someone knows
if this will work with an XL1S and/or can test that....

wrangle him rob ;)

how much more dynamic range does film still have over the current crop of cmos and ccd cameras/video cameras?

None. E.g. Canon D300 mentioned by me has dynamic range not lower than film while in RAW mode, and I guess even better.

what?? are you sure about this? last time I looked film had like 500% more dynamic range then video...I am sure my canon 10D has less then film and it's a professional SLR 6mp camera.....

I think there are two different things we might be thinking about...one is the smallest difference in color(luminosity for one CCD/CMOS) that can be represented...in scott's book Film is shown as 16-bit RGB equivalent, so if you had 16-bit A/D's, technically you should have the same precision in luminosity,

however, another difference is what maximum level of brightness can be shown which i think is somewhat referred to as latitude(?), i.e. at which point film shows 'all white' versus a CCD. In this case, i think all CCD's and CMOS so far clip at a much lower brightness than film...i think this is in part due because film has a logarithmic response to light intensity while CCD's/CMOS are linear.

I have heard over and over, though, that the more precision in a digital aquisition system(i.e. wider a/d's) you can get a better result when applying a logarithmic(or 'S' curve) because you can pull more detail from the darks which would otherwise not be there on a lower precision system.

Once again, i'm not an expert on this, this is my best understanding of it so far....

Juan

that sounds right to me Juan...it is the brightness I was talking about.... I want to see some frame grabs at 30bit!

ok, i am almost 100% this is a 30-bit capture. Note that there are still 6 bits missing because of the limitations of my capture card, so this image has 83% of the total information.

Recall that this is 0.9 pixel aspect ratio, so it looks a bit stretched unless your viewer compensates for it.

There is a hefty amount of noise, which is NOT due to the standard thermal noise in the CCD's, but it is due to my test setup. it's less than before but still there.

I tried to make a large range of illumination, and all i can say is that on the DV footage I cannot see anything in the dark area. I can't see any thermal noise, but that is probably due to the lower 6 bits missing.

Also, this is my 'best guess' in color balance. This is probably completely off, i know nothing about colorimetry. Maybe someone can offer to put the three R,G,B frames together correctly?

http://expert.cc.purdue.edu/~pertierr/dvxcap1.tif

Juan.

For best comparison, please attach a 8-bit normal DV frame to EACH 10 or 12-bit frame you present. That would let us see the difeference. Just simply grab the DV footage and transform it to BMP with all the limitations and arfifacts it has.

PS. The 16-bit TIFF frame that you showed us is not correctly lit. Just pay attention to the histogram of it. most of the information is has in it's lower tonal parts. Please be more correct adjusting exposure of your dvx.

well, this is why i wanted someone who knows what they are doing to put together the image from the RGB frames...also, i think i mentioned it before, i do not have control over exposure yet, because the camera is open and that control is disconnected, so all i have is the 100W bulb i was using for lighting, and i made it as bright as possible without clipping.

Juan

Juan.

Just pay attention to the lighting. Can you properly read the historgram? Check it. So far the image is clearly underexposed. If you have just one light, try to take it closer to the subject so to get more lighting. And don't be afraid of overexposion as this could tell us much when comparing the RAW frame to DV frame.

And grab the DV frame for comparison.

The best test comparison frame would be preparing the scene that one part of it would be overexposed in terms of tipical DV footage; the second part of it would be quite good exposed and the third part of it - underexposed. Prepare it:
1. as a DV frame
2. as a RAW frame.

Don't care about balance as it is a second rate thing. We could correct it in photoshop for our own.

Ok, here's an attempt at what you ask.

These are exactly the same frame, captured through DV and captured RAW.

Now, along with the exposure scroller, the WB button is also disconnected so that is why it all looks so red, but you can see the difference anyway. The menu button is also disconnected so i couldn't take letterbox mode off.

I lit it from the side and had one section overexposed(in the DV viewfinder).

Note there's a lot of speckled noise in the RAW capture as usual, and this is 30bits of 36.

http://expert.cc.purdue.edu/~pertier...aptest1_DV.tif

http://expert.cc.purdue.edu/~pertier...ptest1_RAW.tif

Juan, thank you. That made it.

So it looks as if indeed the tonal dynamics of the RAW exeeds the DV dynamics and as hell it is a good news, making your work Juan not only a hobbyst play but a serious serious thing to turn a prosumer camera into a real high end thing.

I notice there is a lot more additional tonal range in the overexposed area than in underexposed area. Actually, the shadow information in RAW and in DV is simillar. I think this is easy to explain and is not a problem in further shooting using your equipment. The engeneers working on the camera had to make a decision of what part of this wide 12-bit tonal range put into the 8-bit DV output. What would be the choose? Of course the lower part as it makes the whole camera most sensitive.

I guess while shooting in 12-bit it would be best to overexpose the image by 1 or 2 f-stops to gain some more shadow details while still keeping some additional details in light areas over the DV. After all everything could be corrected in post production.

AND THAT IS GREAT.

Juan - tip: When you light the scene, the viewfinder of the camera as well as zebra and all the camera measure tools would be misleading. Actually to properly expose the 12-bit image you should overexpose (in terms of DV) your scene - otherwise we will not see any advantages of the 12 bit image over DV in terms of dynamic range. Just set the lighting with the HISTOGRAM!!! It is clearly seen on the histogram that the RAW image that you sent is still underexposed!!! MORE LIGHT!!!!

Of course, this will damage the DV footage but to hell with it.

OK I just mastered the RAW frame that you sent.

The noise. The thing I found out is that it is NOT random, some distingued areas are just clearly covered by it and others not. Actually I guess this has something to do with spatial frequrency. Those dots are more in areas where color changes most. So, is it really problem with capture card or something deeper? Would capture card react in such a way to high frequency changing not of data rate but information itself??? And pay attention that the noise is made of a pixels wich somewhat lacks R or G component. I never found a noise pixel that lacks B component!!! Maybe that could be a hint?

Milosz,

I have noticed the pattern too, so maybe it is still an intermittent connection? It seems like the speckles happen when a specific bit just goes to zero, and it seems to be only higher-end bits such that when they go to zero, it sets the color very dark...also the fact that it is a specific bit goes along with the fact that it only occurs in areas of similar color, or areas where the color changes through those values.

Maybe I can still fix this problem....if i could only find an exact pattern.

Juan

My suggestion is find out why this happens only to R and G components while the B component is always ok.

Actually you don't need to overexpose the camera by two stops, that's the whole point of using a higher bit-depth image. There's a TON of shadow detail to lift up if you apply the correct curve to the image. Using curves, you can get a really nice image that keeps both the shadows and the highlights. Also if I'm not mistaken, there's probably another stop in the shadows if he's missing the lower two bits of the image. Either way, I think you should be using the zebras, as they will give you an exposure that will capture all the shadow detail without burning out the highlights-maybe you could overexpose by half-a stop over 100 zebra, but I wouldn't go much futher than that, because you don't know when the highlights in the RAW files will burn out, and when they do that's bad. And you don't have to worry about banding with the 12-bit images when you "lift" up the shadows. So I don't really see the harm in underexposing by a bit.

not a DVX100 mod but cool none the less
 

http://www.dv.com/jive3/thread.jspa?...1061&tstart=15

http://home.teleport.com/~gdi/vancecam.htm

Here’s a guy who, like many of us, thought the off the shelf offerings just wouldn’t hack it.

His approach is a bit different but he has a lot of good ideas. His approach is to treat the camcorder for what it is a cobbled together collection of technology, a systems approach.

When he finished he had something that was actually useable.


Just a bit off topic because it's not a DVX100 based system but its cool none the less.

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.

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:)

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.

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

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.