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

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

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/images/products/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/images/products/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.

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

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

Juan, I love you. j/k j/k :P

But you are a good man for doing this all by yourself and all in your free time. *Pat on the back*

Can't wait to see the site!!!!

Hi,

Yes, there are lots of ways to taint the result, particularly if you start confusing yourself with unnecessary stuff like Mr. Adams' system. The system designed with very controllable printing in mind, for use with still photography, so its relevance to even motion picture film work is at best limited - and I fail to see that it has anything to do with determining the absolute dynamic range of an imaging device.

Phil

actually the zone system is a three-fold process: controlling exposure, controlling negative density in processing (for b/w negs), and printing (which actually requires the least amount of precaution of the three steps). and like i said, it's totally possible that even someone inexperienced with a light meter could properly perform the tests, but it's simply my advice to get an experienced professional photographer who's fluent with the zone system. though the zone system wouldn't be used at all during the test, i feel it's safe to say that a fluent practitioner of the zone system will generally have a broader understanding of the way light ratios and spot meters work. basically, it's a safe indicator of in-depth knowledge.

if you were setting up a post facility and needed to setup a router, you could probably have an intern do it-- it's pretty simple and is more or less plugging cables into slots and making a record of it. but if it's something that you want to do once and never worry about it again, wouldn't you prefer to have an engineer with years of experience to do it?

also, based on years of reading ac, it seems like a large percentage, if not most, of "hollywood" dps use the zone system. its advantages in shooting motion picture (in terms of controlling exposure) are more so than still photography, in my opinion. especially when you have subjects moving in and out / to and from light sources, and have blocking changes that are being decided by someone other than the photographer/dp, in addition to the fact that it just plain gives you more control over how your images will look. i'm not trying to sound like a snob -- unfortunately, snobbery seems to often be associated with the zone system, which doesn't make sense because it's pretty easy to learn.

and with shooting video, it's completely irrelevant. all you need is a good monitor.

Hi,

> i feel it's safe to say that a fluent practitioner of the zone
> system will generally have a broader understanding of the way
> light ratios and spot meters work

That's exactly my point, it's got nothing whatever to do with ratios - we're looking at absolute range.

Then:

> basically, it's a safe indicator of in-depth knowledge.

But then:

> it's pretty easy to learn.

Um, er?

My problem with this is that it isn't a safe indicator of anything. It can be learned out of a book in about half an hour. And anyway:

> and with shooting video, it's completely irrelevant. all you need > is a good monitor.

Whaaaat? We're talking about video here! And anyway of course it's relevant! Differently-implemented, but still relevant. The system isn't tied to any way of metering light, it's a way of thinking about pleasing compositions in tonal value as well as space, which is relevant to anything that records an image.

Phil

> The system isn't tied to any way of metering light, it's a way of thinking
> about pleasing compositions in tonal value as well as space, which is
> relevant to anything that records an image."

sorry dude, but you must have the zone system confused with something else (like maybe EVERYTHING ansel adams ever wrote), because it's about the science of light's mechanical effect on emulsion, and fundamentally not about aesthetics.

and again, the zone system is indeed irrelevant for video (at least today's video) because the response curve and latitude are different from film emulsion. in fact, the zone system was developed as a way to have a mental equivalent of what video users have nowadays... a way to see the exact dynamic tonal range of the image we're acquiring (a full-res monitor).

and though the zone system is easy to learn, it requires more effort than thirty minutes of reading. and based on your inaccurate analysis and interpretation of the zone system, that's apparently how you learned it.

but again, i'd suggest juan get a pro who knows the zone system to help him out. at the very least, he'll save on not having to buy a spot meter.

for the sake of everyone else on this thread, i'll formally withdraw from this argument. sorry to juan and everyone else for wasting space.

Jaan, I appreciate your comments because I know what you are talking about. You aren't wasting space.

I think your suggestion of getting the help of a photographer/cinematographer who knows how to use a light meter could help Juan measure the range between the first visible details in a dark part of the image and the last visible details in the whitest part of the image.

A simpler way, not requiring a light meter, would be to shoot a white towel under constant, soft lighting. Stop down until you can just barely descern details in the shadows using a well calibrated monitor. Note the f-stop. Then open up until you can just barely descern details in the highlights. Note the f-stop. The difference is your usable lattitude.

Juan,

if you like, I could give you a hand by professionally grading some sample images for your website. As we all know, the main idea of 12-bit uncompressed footage is less about the appearance of the original capture and more about the expanded grading/scaling/sharpening possibilities in post. Side by side comparisons of dv footage and 4-4-4 footage (both graded for objectivity) could really make an impression on your potential customers.

Cheers,
Chris

Alright guys, here's an example of latitude for ya.


http://www.hot.ee/chrisrubin/leaves_comp_sd.psd

This is a frame Juan posted here several months ago, before he had figured out the exposure / white balance bit. It is in Photoshop format, with two layers - the original (as posted by juan) and the graded one. This image represents possibilites far beyond the scope of dv. Notice also the noise, which, although clearly visible, looks much more like film grain than digital distortion. It's pleasant to look at. I've seen lots of weakly lit 16mm material blown up to 35mm and projected on a large screen - this sample here is very similar to that.

La vita è bella,
Chris

Chris,

I can't seem to open your file in Photoshop 7. I keep coming up with an error that reads:

"could not open: .... an unexpected end-of-file was encountered"

Was this image created with Photoshop CS?

Yes, it's done with Photoshop CS. But I was able to open it in PS 7.0 as well, albeit as a flat image. I think you may have an incomplete download. Try downloading again...

Chris

PS:

here are the same layers as jpg's:

www.hot.ee/chrisrubin/leaves_before.jpg

www.hot.ee/chrisrubin/leaves_after.jpg

Thanks Chris :)

So any ideas how much this mod is going to cost. Plus what about repairs since I'm sure there will be a few bugs until everything is worked out.

Wow... I've never had the pleasure of working with a 16-bit "DV" image before. Amazing out of that "darkened" base image what you can get with a little adjustment of the levels and gamma curve. I took the darker (original CCD) image and applied to very easy tweaks to it and it came out great.

If anyone wants to see, I put it up at:
http://www.madmojo.com/leaves-edit.jpg

I am curious to see what the dynamic range of this ends up being. Seems to me that it would end up being similar or the same to what the camera normally offers, because I would guess that the camera just has a set curve/gamma adjustment it makes on the image before it gets compressed and saved to the tape. If that was the case, it would seem like if you used a similar setting, that you could expose properly for the tape and the firewire out, which would be very nice for "backup" and post processing reasons.

Of course, I may be way off base here.

"Seems to me that it would end up being similar or the same to what the camera normally offers, because I would guess that the camera just has a set curve/gamma adjustment it makes on the image before it gets compressed and saved to the tape. If that was the case, it would seem like if you used a similar setting, that you could expose properly for the tape and the firewire out..."

Eric,

This is what I figure as well. It makes sense. There might be a little gain in dynamic range, but what's important is to test and determine how much gain there is if any.

That's why I suggest the dynamic range test as I posted in my previous post. Others might have suggestions too that could be better.

Yes, that's a great idea. I'd love to get my hands on the same image taken with DV and with the mod, in the same lighting conditions, etc. to see what kind of gamma/level adjustments could be made to make them look as close as possible in terms of hue, luminance, etc.

Theoretically there should be a huge gain in dynamic range, at least 2 stops more. The reason?

With the current DVX100, you are dealing in post with a gamma-corrected, 8-bit, 5:1, 4:1:1 compressed DV Signal. If you ever try to underexpose your DVX and then "bring up the shadows", forget it, unless you like the look of those square pixelated compression arifacts lurking in the shadows. With 12-bits and the number of levels it gives you (4096), there is a lot more room for underexposure to bring the highlights down and under control, but with enough information in the shadows to then bring them back up without compression artifacts or banding.

Seems to me that it would end up being similar or the same to what the camera normally offers, because I would guess that the camera just has a set curve/gamma adjustment it makes on the image before it gets compressed and saved to the tape. If that was the case, it would seem like if you used a similar setting, that you could expose properly for the tape and the firewire out...

Yes, that will be the case, but the nice thing is, you don't HAVE TO expose like you did with DV. You now have the freedom to underexpose the picture to keep the highlights under control, but still have plenty of information in the shadows to increase the color saturation down there, and also normalize them/apply gamma, etc. without banding or other compression artifacts poking their heads up. That's why I'm saying at least 2 if not 3 more stops, depending on the amount of noise in the shadows. Now your only limiting factor in playing/color-correcting the picture is noise, not extreme compression and it's nasty side effects out of the current DV stream from the DVX.

So, how about some proper tests, Juan? It's not anything that any of us can do, even from images you post, unless you post a whole slew of DV and uncompressed images side by side. You can use a single set up either outdoors or indoors, and just run the gamut of full stops the camera has, from next to fully closed to fully open, while noting all the fstop settings of each frame you capture.

We will be able to see on what frames you just start to see shadow detail and on what frames you lose all your highlight detail. The lighting has to be constant and should be within a range that is useful for the test. Some experimentation should help figure out what that is.

hey everyone, i did some quick tests to see roughly what the potential latitude might be. the info and images are at
http://www.jaanshen.com/juanmod

though unscientific, they're very exciting (at least for me).

BTW, with anything more than 1000:1 (10 f-stops) and 12-bit linear, you're going to get visible banding in the shadows. With 1000:1 you're essentially exposing a 90% white card at 10%-that's very, very dark, and you're only giving 400 levels to that top 90% range, excluding the noise that is present that far down in the luminance range. So your 11 f-stops might be a bit optimistic, I'd say we're probably at 10-10 1/2 f-stops depending on noise. Most likely 10 f-stops is the limit with tolerable noise levels.

Joel,

I already did a test such as the one you are describing. I took a set of images at of the exact same scene with the same settings, while varying just the aperture. I took DV and RAW counterparts of each frame.

expert.cc.purdue.edu/~pertierr/LatitudeTest.jpg

You can also clearly see the artifacts in the redhat box. The only problem with that test was that I didn't adjust white balance, so the dynamic range is actually more than what you see there. White Balance works by limiting what the maximum value that comes out of each A/D is. So even though you can represent 0-4096 (12-bit) levels on each channel, you might only get an image with, say, 3980 as the maximum, washed out white on the RED channel for example.

Yes, and that makes me wonder....what color do I have to put in front of the camera such that a white balance adjustment will yield the absolute maximum range from all three A/D's? THe image color would look terrible, but it would allow the maximum resolution for working in post! It's only a little extra color resolution, but it sounds simple enough to find out.

Here's a PSD capture, uncorrected but with WB adjusted on the camera. Only thing I did was align the frames as much as I could.

http://expert.cc.purdue.edu/~pertierr/cap12_RAW.psd