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Old May 17th, 2004, 10:27 PM   #661
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Very interesting...so it's sort of an inverse anamorphic adapter? Fits a 4:3 image into a very wide CCD? Interesting trick, probably why the DVX footage looks so sharp.

If this is correct, then it would greatly help to first up-rez the raw data and then resize to the correct aspect ratio...or even better, leave it in the original aspect ratio and interpret the correct aspect ratio at play/render time?
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Old May 17th, 2004, 10:31 PM   #662
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Juan, you definitely don't want to up-rez and then downsize to the correct AR. You always want to do all your transformations in one step. So if you're going to DV, it's best to just do one transformation to DV size. If you're going to HD, you do one transform to that size. As soon as you do two in a row, you've done two interpolations, and you'll start to see generational problems

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Old May 17th, 2004, 11:09 PM   #663
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capture stills

It would actually be better I think if you not do the DV RAW capture comparisons outside like you did last time. Something there in your room is better. Something totally still and with enough detail to do indepth comparison of the channels in both DV and RAW. That outside shot was good for latitude, but if there's even the slightest bit of wind then you'll have to search tirelessly for the exact same two frames on the RAW and DV cause the tree leaves will be different... If you just shoot another Test Chart for example, you can pick any two frames of either and they should be exactly the same... that is if you don't hit the camera again ;)

John
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Old May 18th, 2004, 03:31 PM   #664
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Also

Juan,

Can your test grab include some sort of detail very close to the right and left edges of the frame so that I can compare the FOV issue I'm seeing with the green channel. I want to compare the green channel in the RAW with the green channel of the DV.

John
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Old May 18th, 2004, 08:47 PM   #665
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idea on anamorphic adapter

juan - do you have access to the anamorphic adapter for the dvx? in these discussions about the stretched image, you said something interesting, about it being "like a reverse anamorphic adapter" - i wonder if this was done intentionally, so that when you use the panasonic anamorphic adapter, it actually matches somehow with the pixel count of the CCD? it seems like the camera was designed from the start to be used with that adapter...

perhaps if you put the anamorphic adapter on, you could have a much higher resolution anamorphic image than the dvx would give you otherwise. it might be worth borrowing (or renting) one? perhaps there's someone in your area that could loan you theirs for a test.

-benjamin
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Old May 18th, 2004, 08:58 PM   #666
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i realized i didn't finish my thought... the pixels on the CCD are square, yes? so the camera, as it processes, is squishing the image horizontally, but perhaps when you have the anamorphic adapter on, the math will work out so you take those square pixels and expand them slightly to make them rectangular ntsc pixels, and we could have a perfect 16:9 camera on top of everything else!

i don't know how to test this, mathematically, without footage shot through an anamorphic adapter though. any thoughts?

-benjamin
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Old May 18th, 2004, 11:53 PM   #667
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there's a math way to figure this out

I agree that anamophic was build especially for the DVX, but that's more because of the 72mm diameter thread I'd think.

I'll try to figure it out... my gut says no though.

John
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Old May 19th, 2004, 12:37 AM   #668
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registration problems; HD-SDI; EZhook?

Juan,

I hope you can resolve the rgb registration problems.

Adding the anamorphic adapter would be a good idea if that is the ideal way to use this system (and I think it is). As I recall from the literature the Anamorphic adapter is intended to let us use "all the pixels" in the sensor rather than crop to get 16:9.
Unfortunately these adapters cost $700-$900.

HD-SDI transmitter:
Xilinx has some interesting application notes of possible interest.
an HD-SDI transmitter using the virtex II FPGA:

http://direct.xilinx.com/bvdocs/appnotes/xapp680.pdf

I think this might have some data on the HD-SDI spec.

There are a no. of relevant app notes on this site if you plan to use this part. There is also a ref. design for a SD-sdi transmitter.

I would still like to know what you are using to clip on to the altera chip? I would like to experiment with my DVX100. I would also like to try hooking up to the chip in my Sony DXC750 and DXC950 (these camera's make 700 lines resolution interlaced).
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Randall Larsen
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Old May 19th, 2004, 07:27 AM   #669
 
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I have just finished shooting a feature with the DVX-100 with the anamorphic adapter on it. Will it help you guys at all for me to upload a clip?
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Old May 19th, 2004, 01:16 PM   #670
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SDI info

Juan,

You'll find additional info on the SDI spec at:

http://www.xilinx.com/xlnx/xweb/xil_...lication+Notes under SDI.
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Randall Larsen
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Old May 19th, 2004, 08:05 PM   #671
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Anamophic

Laurence,

do you have a raw frame grab as DV 720x480? That's all we'd need to see.

John
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Old May 20th, 2004, 01:01 PM   #672
 
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Well, you're going to have to pardon that I'm not as technically proficient as you guys are. After reading around this site for a bit, I've come to the conclusion that my version of a frame grab may or may not be what you need. When you say you need a RAW capture, I truthfully don't know if I am capable of doing that or not. I recorded the movie footage with the DVX-100 & the anamorphic adapter attached, and the camera mode in 24p advanced. The footage I have was recorded via the DVX onboard recording system (so that's what we're starting with. My method of accessing that footage is a typical dv camera (sony vx-1000) that I can either output a signal via s-vhs or of course standard 1394 small firewire. I bought a non-linear editing system back in the day (6 years ago) from matrox (MATROX DIGISUITE LE) that had s-vhs and BNC component I/O, but no firewire, as firewire was not as popular then (used that system to edit a feature with 16mm film footage transfered to beta-sp). I'm using a PYRO 1394 Drive Kit that says it transfers rates up to 400 Mbits/sec. It came with some cheesey software called SONIC DVD. So I connect the camera to the external Pyro drive via a firewire cable that I assumed was standard small firewire (Hey, but maybe since it says 400 Mbits/sec, it's actually firewire A or B whatever? - - - hope I learned something already). And then I capture with SONIC DVD software. Then maybe send you guys the file here? Is this the right direction or is this useless to you guys? Maybe I can capture with some other software that would be better? Not sure what you guys would recommend. Let me know and I'll be happy to do what I can.
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Old May 20th, 2004, 02:52 PM   #673
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RAW

Actually I didn't mean to confuse you. When I said RAW I just meant a frame of the DV as it cam off of the tape and out of the camera through firewire. I realize in a discussion like this one the word RAW can get confusing.

Anyway, when you capture to Sonic DVD is there a way to export a single frame as like a Tiff or PNG or even a JPG.

John
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Old May 20th, 2004, 10:39 PM   #674
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Hey guys,

Sorry for the short 'dissappearance' :)

I'm well on my way working on the prototype, and already have all the FPGA's and programming stuff, along with the other components. I have a design for the casing which I will probably make in my milling machine/lathe but that comes later.

I DID find a green posterboard but I left it at work today. So, i'm going to hook everthing back up and do some tests using DV tape and RAW capture of a resolution chart and maybe some other indoor shots.

I'll make sure that i don't bump the camera this time.

Also, to answer Benjamin's question, i am almost 100% that the pixels in the CCD's are NTSC, (or some other aspect ratio) but not square. This is because the RAW images clearly look stretched when viewed with square pixels on a computer.

I do not have an anamorphic adapter, and even though it is something that i've always wanted to purchase i can't really do it right now since i'm working on this project. But i guess if anyone lives somewhere in/adjacent to Indiana and wants to help that might work. :) I drive all over the state all the time anyway.

Juan
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Old May 20th, 2004, 10:55 PM   #675
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Another quick question...

About the SDI implementation, what use could it have? If you want to use it, you're going to need a computer anyway, in which case you can just plug-in a FW800 cable and watch the preview/capture with that right?

In either case, the video coming out the SDI port would not be the full RAW data.

I'm just curious if this would really be a useful feature. As for a monitor, analog S-video seems to be the best option, or do most people actually use SDI monitors???
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