At full quality 4:4:4 36-bit RGB 24P, with no compression, it consumes about 40MB/sec. I am working however on lossless compression such that the number can be greatly reduced while mantaining full quality. If you drop the color precision down to 30-bit RGB it comes to ~33MB/sec uncompressed.

Now that you mention it, there ~is~ a chance that this might all work over Firewire400 after all. I went with FW800 just to be on the safe side, but the total bandwidth was always a bit under the FW400 bandwidth. Given that the host drive can handle the full 400Mbps rate, it just might work with standard firewire drives.

Do note, however, that i've seen older firewire 400 devices that do not operate at the full rate, plus the main point is that the actual drive that is in the Firewire casing can handle the bandwidth.

I'm confident that all new drives can handle it fine.

Juan(Pablo) :)

Whoa . . .
 

144GB/hour . . . so nothing lest than a terrabyte oughta do. . . :)

Where's that URL, Juan . . .??? Need some help with the web design? I can help ya out . . .

Hello Juan and all the lovely think tank!

This is my first post here although I've been checking this thread almost every day since early February (hey, better late than never).

Anyways, fantastic work... I don't care if hell freezes over, I'm gonna buy this thing.

I've done a lot of color grading work (both film and video) and I've had lots of fun playing around with the stills you've posted. A graded image off the mod looks surprisingly pleasant at 2k and 4k resolutions, it doesn't feel forced at all and the extra bits give a lot to 'tamper' with. Beautiful...

Juan, I'm sure your fanbase will grow fast after you get your web page running... screaming girls, paparazzi... you know the drill :)

OK, a couple of questions:

1) Did you get the RGB alignment problem sorted out? BTW, most prosumer 3ccd DV cams I've worked with have their channels very slightly misaligned. The compression usually hides it well, so it hasn't been that much of a
problem (until now). Fairly impossible to detect on a SDTV monitor, but uprezzing gives it away.

2) You have mentioned that it is still possible to record simultaneously on standard DV tape (to use as dailies/backup). As uncompressed capture requires wider aperture than standard recording (due to added stops), shouldn't the DV video be totally overexposed?

3) The Mini35 issue still bugs me. I'm gonna be shooting a movie next year (budget around $2m), and I would
definitely like to use your mod (or several of them). But Mini35 is pretty much a necessity here (gotta use
anamorphic primes). It would be good if they didn't null each other out. There seems to be enough space
between the support rods and the camera base attachment, but I'm not sure.


Thanks again and keep up the good work!
Chris

Not to speak too soon (yah, I know I am) but if this works out on the DVX, maybe he'll make one for the XL2, so you won't even have to bother with the anamorphic primes (can use more accessable standard primes) and you won't even have to worry about the down-sampling of all this prime Canon pixels to fit on a miniDV tape.

Hint, hint...

Also, I've been following this post fairly regularly, but I must have missed the part where the uncompressed image adds stops to the recording... Is there a simple answer to why that is?

Non-downsampled XL2 - now there's something intriguing! Now if only I could afford one!

Chris: This is sort of off topic, sorry, but what do you use to upsample video/images?

Chris:

1.Yes, the alignment problem can be perfectly fixed with some shifting and slight resizing. However, since I only have one DVX I leave open the possibility that the corrections that work for my DVX might not work on another, so my code allows the user to experiment in order to obtain the right alignment.

2.Depends on the scene and settings, but yes it does happen. There's no way around it unless I heavily modify the camera. Most of the shots i've posted however, didn't use the full dynamic range, and thus the DV output was still usable. I've found that to really get a nice film look to it, I under-expose the scene to avoid complete white-outs and then take advantage of the color resolution and apply a gamma curve.

3.That's a tricky one. I completely understand the need for it, but the problem is twofold: the wiring coming out the bottom has to be kept as short as possible, and in addition the box is pretty large so it would be hard to mount it elsewhere. The only option I can think of is a side-by-side arrangement. It will be huge, but it will allow the mini35 to be mounted.

Eric:

The DV process limits the dynamic range of the CCD's in order to comply with NTSC standards. My mod actually uses the full latitude of the CCD"s, which in my tests has resulted in about 2-4 additional F-stops of latitude.

Cheers,
Juan

Come on Juan!!!!!!!! What's the URL?!!!!!!!!

Thanks Juan. Sorry to go over this again if it already has been. Are the stops your mod adds on both sides evenly or does it stop down more than it opens up stops?

Regarding the mini35 mount, would it be feasible to to make your box wider, but shorter so that it could mount to the rods and fit between the camera and rods? (not sure what the longest wire length would be).

micmac chez les mac cormack
 

Hi Juan and everyone.

Lots of people think you're a lier and a psychopath.
For people interested about that go on cinematography.com :
http://www.cinematography.com/forum2004/index.php?showtopic=1887&st=15

I don't have a personal opinion about it.

I think what you've done is possible even if I don't understand what you don't give the so long awaited URL.

The only thing annoying me is your price.

8500 $ is too expensive.
Especially when you know that some amazing HD will appear soon.
So, is it your last price ?

---

Chris Rubin if you have a 2$ m dollars budget what you spend time with Juan's mod ?

Flax, all i'm gonna say is that you have the wrong person. I checked the link and they are talking about someone called Pete, who wants to do some low-cost HD solution.

And i haven't announced the price yet but it will be waaay lower than $8500 that's for sure.

Juan

I read into it further, and it seems it was all started by a person called Pete Wright. In his listing, he used a lot of innacurate information, including random prices for my mod(thus the $8,500), and even incorrect resolution sizes.

If you have any questions whasoever, please post them here or feel free to email me directly as much as you want.

I can email Pete Wright but there's always going to be someone out there that posts incorrect information.

Cheers,
Juan

Thanks Juan
 

It was clear when I read those posting that this guy was a little off.

So . . .the moment of truth . . . how about that URL? :)

thank you Juan for the answers.

Eric:

I'm not eager to embrace XL2 just yet. But I'm not gonna rule it out either. I definitely do not like the way the available screencaps look (esp. 16/9), but as this is just the beginning, I will not (yet) blame Canon.

Aaron: I use algolith for upsampling.

Flax: I have many reasons for going DV, not least of which is that it enables me to put a great deal more money in front of the camera, so to say. And I get to keep the gear as opposed to taking it back to the rentals. Before Juan's mod came along, I was planning for Cinealta, which is the usual fare around here.

Cheers,
Chris

who's right ?
 

Hi Juan,

Thanks for answering.
My purpose is not to spread bad rumors...

David Mullen on this topic on page 2 is just saying that Pete Wright and you are the same person...

...

Btw, this is a good news to hear that the price will be lower than $8500.

:)

Flax.

Flax,

I read that whole thread, and at no time does David Mullen - or anyone else for that matter - say anything about Pete and Juan being the same person.

If it is not your intention to spread bad rumors, please take greater care before posting, or you may unintentionally spread them anyway.

Hi Justin Burris,

You're right.
This topic started on dvxuser confused me :
http://www.dvxuser.com/cgi-bin/DVX2/YaBB.pl?board=Events;action=display;num=1092616258

I guess I was very surprised to see this guy knowing the price of Juan's mod before the website was done.

You know, I will be the first happy to see the Juan's mod available.

Be sure I will take greater care in the future.
Thanks for your trust.

This subject seems to make
people react with a lot of passion...

Chris, thanks for your answer. When did you plan to shoot ?

Here's something similar but upwards in the $60K price range.

http://www.kinetta.com/

An interesting venture by filmmaker Jeff Krienes.

For everyione trying to figure out the URL www.waylowerthen8500.com does not work.

Okay Juan, here is my guess it is XRS-1.com, xrsone.com or xrsjuan.com or xrsjuanmod.com (.net, .org. etc...). If I guess right, how about a discount on the mod.

www.Juan-is-da-man.com

People need to chill out a little. Why would Juan be ignoring you or this project? He is probably busy sorting some things out that are taking longer than expected. There are a lot of considerations, and if you haven't noticed by now from this thread, Juan tends to be ever so slightly over-optimistic with his timelines.

I'm working on all of this as fast as I can, and i want to make sure the site is working as best as possible before I make it public. I'm not a big fan of "under construction" sites. :)

It's very close, i'm working on some images to better illustrate the content.

Juan

www.joelcorkinisrightandweshouldbackoffonjuan.com doesn't work either.

Nick you're killin' me over here!!


es

Hi everyone,

Juan,
will the FW HD need an external power source or is there a way to use the
camera battery?

great job!

can't wait to send you my dvx100a pal cam.

As for the design right now, all it cares is that the drive is an external Firewire 800 drive and it is fast enough to handle the bandwidth. It has no means to power the drive from the camera, because all Firewire 800 drives have different power supplies, so it would be impossible to predict what kind of drive the user will buy to use with the system. I would have to limit what brand/model of drive you can use with the device in order to provide power for it, and I don't think that is a good idea.

One idea is to provide batteries for different drive systems. They all have different plugs and voltages and such, but in the end it is not terribly difficult to put a battery system together for one of these drives.

We could even provide a small adapter, one end which plugs into the power of whatever drive the user has, and the other end plugs into one or more generic batteries such as RC Car batteries. I did this once for a portable radio application and it worked very nicely, specially for demanding applications. The batteries and drive can then be carried together in a shoulder bag, with only the firewire cable exposed.

Juan

Since the NTSC pixel yield is 773 X 494, am I correct in assuming that without using the ana, or in-camera squeeze or letterbox, you can get a 773 X 435 16X9 image by cropping in post.

Also, since the resolution is higher than DV, is the CCD picking up more than the viewfinder/monitor would show, or does it pick up the same image and downsample it to DV? And if it's a larger picture area than a monitor would show, how difficult does that make framing shots?

Close enough:

773 divided by 1.78 (otherwise known as 16 X 9) = 434.27




Yes your monitor wouldnt show the entire picture that the CCD is capturing. I would think a overscan monitor would work fine but then again thoughs may not farther then showing you the edge of a NTSC standard frame (720 X480). Anyone?

Looking at example frames Juan has posted, it seems the 773 X 494 resolution does not represent correct aspect ratio: the images coming from the ccd have a sort of backwards effect of an anamorphic adapter. In order to correct it, the image has to be resized to 720 X 540 (or any othe size fitting the 4x3 aspect ratio.

peace,
Chris

edit:

I'm speaking in terms of square pixels here... on an NTSC monitor with 0.9 pixel ap, the image should appear 4x3. I do not have one (PAL country), so I'm not sure.

the 773x494 image still uses non-square pixels so you actually only have 687 x 494 raw square pixels. 16x9 HD uses square pixels so a 853 x 480 HD frame is square pixels. This is why cameras such as the XL2 have 960 pixels for 16x9. 960 equals the non-square size for 16x9. Once you convert the 960 to square pixels you get 853. yes you could use every pixel as is in 773x494 but then your actors would hate you because they would look fat.

So as you see we are only gaining an extra 47 square horizontal pixels in the image from the raw capture. 687 compared to 640.

Remember you can't really compare 853 to 720 because they are different pixel formats. 853x480 has to be compared to 640x480 or 720x540 if you want to blow up your vertical resolution with interpolation.

Ok, I need everyone's help here:

In the latest tests i've been doing, I am getting a properly exposed DV image of a well-lit scene at F16, with some minor washout areas, but I am getting the same frame properly exposed with NO washout at F6.8 for RAW.

I highly doubt that I am getting 7 F stops of added latitude, so perhaps this method is not accurate? Any suggestions? Anyone?


About the frame size, on the DVX the CCD"s yield 773x494, in NTSC aspect ratio. But the lens itself stretches the image a but horizontally to take advantage of the wide CCD. So, after applying a 0.9 ratio for NTSC, the image needs to be compressed horizontally until a 4x3 aspect ratio is reached, plus the overscan area.

Juan

That's not seven stops the way I count.

The best would be if you could post another example where you put side-by-side of DV-out vs. RAW-out at a bunch of different exposures on the same scene,

You did one of those before in the thread, but before the white balance was working, so it gets pretty goofy.

Try to get something with insane dynamic range. An unlit room looking out towards the window at daytime or something. Like:

http://www.theasc.com/magazine/image...cts/Prod3D.jpg

Although I can understand if you don't wanna bother with the model and the macbeth chart. :)

Yeah, f6.8-f16 is three-and-a-half stops.

I concur with Kevin. That sort of test would tell us much more. If you happened to have a lightmeter on hand to tell us what the different areas were reading, then that would be even more useful.

Ok...well it just happens that I found a local camera shop, so I'm just gonna invest in a light meter and solve this once for all.

Although 3 1/2 stops sounds about right.

Juan

Cool. This type of notation makes it very clear:

http://www.theasc.com/magazine/image...cts/Prod3A.jpg

You probably already know this, but just in case: if you are going to get a lightmeter, a Spotmeter is the way to go for these tests.

Filesystem
 

Hi,

Just out of interest, what filesystem are you using on the hard drive? I ask this because I don't know what hardware you have in the device and if it isn't a full microprocessor system, implementing different filesystems is presumably quite a lot of work. What's ideal for a WinNT user (NTFS) won't be ideal for a Mac user. I believe both can read FAT32 formatted volumes, and that filesystem has been implemented in embedded systems before. You aren't just doing raw sectors?

Phil

f-stops
 

the difference between f6.8 and f16 is 2.5 stops (5.6, 8, 11, 16). of course that's assuming that the dvx100's fstop ratios are truly at a doubling ratio... i have no idea if video cameras are expected to be accurate in that realm.

and the difference in latitude (between the raw and dv25 frames) based on fstop may be misleading. more than likely, there is indeed extra lattitude beyond the total black and pure white of the dv footage being laid to tape. but the chances that it exceeds 10 stops is very low.

i would assume that the raw frames (that appear darker) are being sent to the dsp (or whatever it's called) and are having the almost blacks and almost whites clipped and the gamma adjusted (to make the midpoint brighter). the clipping of toe and shoulder are probably a built-in quality control issue to compensate for slight variations in the ccds from camera to camera. and the gamma correction/midpoint brightening is standard proceedure for dealing with linear images.

so basically, i'm guessing that if you take a raw frame and adjust the white/black points and adjust the gamma, you could result with a frame that has similar "exposure" and shadow noise as the equivelent dv frame.

if you think of a semi-equivelent in shooting film, exposing at f6.8 would be overexposing, thus minimizing shadow noise, and increasing color saturation particularly in the shadows, but at the potential cost of blowing out highlights. exposing at f16 (based on the fact that the camera considers this a "correct" exposure) would be like a "normal" safe exposure that is balancing between maintaining highlight and shadow detail. just keep in mind that the raw frames are (i'm 90% certain on this) linear, so they will by default look dark. raw frames are not intended to be viewed by human eyes without gamma or color correction, so exposing your footage based on how the "straight out of the box" raw footage looks is probably not a good idea.

i would liken the raw frames to a film negative... it contains more image information than you will probably ultimately be using in your final piece, so exposing for the freedom of options in post is usually the best choice.

i was a cinematography emphasis in college, am fluent in the zone system, have shot negative, reversal, and dv professionally and for personal work and also have done post color grading professionally. i'm more than happy to try and help settle the latitude issue and/or the raw-to-dv exposure discrepency. if you'd like my input juan, just send me a raw frame with considerable luminance variation (the asc image kevin posted is a great example), along with the dv frame equivelent.

i'm not at all bashing juan's work or his mod -- i'm probably more excited about this than anyone else. i'm just trying to help everyone with whatever knowledge or experience i have. and regardless of the mod's true latitude, i can say that based on tests i did with the old frames juan posted, the raw frames give us incredible flexibility in color manipulation and the ability to adjust the luminance in the shadows and highlights with minimal side effects (banding, noise, etc.), especially when doing color correction in floating point or 16-bit software. in my opinion, that's way more valuable than having 10+ stops of latitude.

and juan, if you are going to do a scientific latitude/exposure test with a spot meter, i would highly suggest you ask an experienced professional photographer, preferably fluent in the zone system, to assist you. though it's perfectly possible for anyone with a spot meter to do it correctly, there's a lot of ways to accidentally taint the results.

hope this helps,
jaan

How's the website going, Juan?

The code is done, I am ironing out the content...for example I want to get an accurate measure of how much additional latitude I am getting. i do not want to make false claims on the site, so I'm trying to make sure everything is as acurate as possible.

Also, i'd like to take the chance to thank everyone for their continued interest, support and patience. I'm trying to do this as fast as I can, but it's just me :)

Somebody once said: fast, good, cheap...pick two. Hopefully this will give good(great) quality for a cheap price, but it takes a while.

Juan