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Old July 25th, 2004, 04:55 PM   #1066
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Juan, I'm just saying that it's best to use a lens that was designed for your sensor size. Can you find me a 25mm SLR lens at f0.95? How about an 8mm at f1.4?

Jason and I are looking into physical low-pass filters to deal with the moiré -- I'll keep people posted on that.

@Juan: "I don't understand what's the relation between a bad white balance and an Altasens chip."

Okay -- let me explain it. This is an 8 bit camera. The RGB gains are software, at 8bit (not hardware at 10bit). This means there's no way to adjust the color in hardware. Which means that in order to white balance, you need to adjust the image with software. With 8bits, this is simply not possible. When you shoot indoors, you get a yellow-orange image. If you don't want that, you must use an #80 blue filter, because that's the easiest way to color correct the shot.

The Altasens will run at 10 or 12 bit, giving you a bit more flexibility to white balance with software.

That is the relationship between bad white balance and the Altasens.

@Wayne: "You could work around it, but it will need specialist USB drivers (and system setup) like Steve does with GigbitE (ask Sumix)."

Or we need a FW800 camera, like Sumix may be developing...

@Anhar: "why not make they priority set to the highest and shutdown all other programs/ internet connections etc.."

This is a dedicated machine. There are no other programs ever running.

"and have a "clean" defragemented harddrive?"

I'm recording to RAM.

"Also @ Ben once you have your captured file (AVI?), is it ready to play?"

No -- it captures RAW video files, and then their software converts it to a lossless AVI.

"i'm thinking of getting this cmos camera:"

That's the same exact sensor (looks like the same exact camera) as the Sumix 150c. I think Sumix developed the 150c, so they must be reselling it to other companies...

- ben
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Old July 25th, 2004, 05:52 PM   #1067
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<<<-- Originally posted by Ben Syverson : @Wayne: "You could work around it, but it will need specialist USB drivers (and system setup) like Steve does with GigbitE (ask Sumix)."

Or we need a FW800 camera, like Sumix may be developing...
-->>>

well tell me more ;), I'm sick of waiting for a HD camera (I have been waiting since before the HD10 for a better camera that will do 25fps for PAL HD markets).

<<<-- Originally posted by Anhar Miah : @ Ben

why not make they priority set to the highest and shutdown all other programs/ internet connections etc..

and have a "clean" defragemented harddrive?
And lens + USB cable, what software will i need to start capturing video
P.S i have a 2.6GHz Toshiba laptop (i hope its fast enough) -->>>

Actually you can make a difference setting up the computer, as windows runs a lot of service programs in the background (aswell as thrid party anti-virus, secuirity, firewalls, and unistaller monitors). These play havoc with smooth performance, every time they task switch is a big hit. I have posted links to optimisation guides (for realtime processing) on the technical thread, I think one site has links to setups for different processing applications.
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Old July 25th, 2004, 05:55 PM   #1068
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ugh, me too.

It seems like with every camera out there that has some promise there's always some other compromises!

.2*90 frames = 18 frames

.5*90 frames = 45 frames

1*90 frames = 90 frames

I'm not trying to beat a dead horse here, but I did want to point out that the frame rate that a recorder will be running at is 23.98 or 24fps.

I noticed in your frame rates that you were off by almost 1fps in some cases. At the end of 90 seconds that's more than 3 seconds off. Very noticeable.

I'm not trying to spaz out with this issue, but it is an issue, and there must be ways to deal with it. And again, my main wonder/puzzlement is that if this is a computer with clocks, etc. how come there is no consistent frame-rate?
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Old July 25th, 2004, 06:12 PM   #1069
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Ben and Juan. About the 35mm adaptor benefits and problems.

From what I've been told the only benefits are: GG 35mm adapter, cinematic/arty shallow DOF, and softening of the image with far better optical properties than standard consumer video lense (cheap secondhand). The problem is that yuou ussually loose 1 to 2 stops of light from using the projection plane, but they are working on diffferent methords that might gain (I'll stop there, because last time I said this I got a long thread full of irrate people not understanding what was being said arguijng seimantics?? arguing with people that actually knew what I was talking about).

I only suggested the version without the GG to increase the image brightness in low light situations, using a seperate 35mm lense. As far as I can figure out the aperature ratio tells you how well lit every piont is over a set area. 35mm has, 4 times more area than 2/3"???, so concentrating a good F1.0 slr lense onto 2/3' chip (though yours is 1/2") would give two stops more light than a F1 2/3" lense. Is that right?

Now what Ben has said about putting a lense inbetween producing problems (I think they are discovering that over at the adaptor threads, but I haven't been keeping up with them) is true. It increases variouse chroma abbervations etc, but I think they are using achromatics?? (dual lense type lenses) to correct this. So you can get your cake and eat it. Then again, I am not an optics or production expert.

Thanks

Wayne.
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Old July 25th, 2004, 06:16 PM   #1070
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Wayne,
Achromatic or Apochromatic.They are design to avoid color aberrations.In no way anyone can put a single lens system, because this (as a magnifier or Lupa) will ruin the image.
The light transmission for a good quality lens is around 98%.So you just loose 2%.
No problems here about resolution cause they usually resolve more than 200 lp this days.

Ben, after tweaking carefully the Dollar image, to white balance it I needed to increase Blue 30%
The same happens with the Tomato shoot.
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Old July 25th, 2004, 06:38 PM   #1071
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Is this a proper workflow?

Hey guys. I'm very elementary at this and I realize you guys aren't! So , if you have a chance, please let me know if this is good and proper. I'm ready to try this and was wondering if there is anything I'm missing here. Here are the links for the goods...

Camera...
http://www.edmundoptics.com/onlineca...=2490&search=1

Lens-to-body adapter for Canon EF lenses...
http://www.birger.com/html/ef232_home.htm

Hard drive for CameraLink connection...
http://www.leutron.com/english/product/lvmpc_d.htm

Now what am I missing? Something to view it with! Or, should I just capture to a laptop?

What's missing here to make this work?
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Old July 25th, 2004, 06:49 PM   #1072
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How bad is the rolling shutter? I know you said not bad, but I'm wondering at 1/48th of a second how it compares to Obin's camera.
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Old July 25th, 2004, 06:55 PM   #1073
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Ben, Jason:

I have a CC version of the Dollar image with almost all the color moire removed.Can any of you post it?
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Old July 25th, 2004, 06:57 PM   #1074
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yah, email it me at jrod@mindspring.com
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Old July 25th, 2004, 07:45 PM   #1075
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Ohh, you are good. I can't really help you, (Obin, Rob, Jason, Ben and Jaun could) but thanks. I can't keep up with all this research, but in the other technical thread I've posted links to cameralink home pages products registery. If you, or somebody else, would like to go through them looking for good cameras, cheap frame grabbers, and good pro video control/caputre software and report back to us it will be helpful for us and you.

So far this is what is happening, two groups are trying to work on provide/cinema freindly software to link any cameralink camera to any codec to any popular supported NLE. It's not finshed, until it is we can't select the minium configuration for certain, or say exactly which system is best for what level of aquisition (but you can allways get something that is more powerfull than needed). This is because continouse optimisations of the software will significantly boost it's performance.

We also are not really selecting the best hardware peices until the new cameras are comming.

A few people are going to try a FPGA compresion accelerator, and seperate codecs are being developed/adapted.


I've got a request, we need volunteers to find suitable components for the system:

We really need to pick up our game. I have done a load of research here, a number of others have too. But it is too difficult to do everything, and I have had to leave a lot of things undone. Steve N has suggested this before, and if you think I post too much, that is because I do lots of research compared to most, and have a lot of technical knowledge because I have looked in to making variouse products in the past. I would like to spend time on other aspects of the project, and other things. I would like volunteers from people who aren't allready doing a lot on the project. Anybody interested?

What we need:
  • Pro video capture/control software for the cameralink, usb2.0 and gigabit cameralink cameras.
    Cheap capture cards.
    Good cameras.
    The fastest hard drives raid or normal ata/sata, 3.5 or laptop.
    The best/cheapest motherboards, big, small, or low powered for the capture interfaces above.
    The best/cheapest small computers and laptops.
    The best/cheapest system workflow solutions.
    The best/cheapest power supply/battery options
    The best/cheapest sound options.
    The best/cheapest case options.
    The best cheapest monitors.
    The best/cheapest software/codecs.
    Facts and figure calculations for target performance (advanced).
    Remote controlled (robotic) lense system and camera mounts.
    etc.
Collect the links and information and post to the technical thread and the wiki. A good place to start is all previouse posts and links here, in the viper thread, in the homemade camera design thread, fpga thread and techncial and general threads.

http://www.dvinfo.net/conf/showthrea...threadid=28781
http://www.dvinfo.net/conf/showthrea...threadid=28779

This would require objective scientific investigation and evaluation of the options, specifications, stats and performance, and would suit technical people or engineers. It needs to be a systematic, logical "checklist" investigation down every avenue and option. If you can self organise, and group organise to divide up the work, it would help.


Thanks

Wayne.
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Old July 25th, 2004, 07:58 PM   #1076
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Hey Obin and Steve,

I read this over on the Micron site:

Quote:
No Artifacts, Smear, or Blooming Means Higher-Quality Images


With our active-pixel architectures, the RMS input-referred noise is comparable to the very high-end (and expensive) CCDs. Both technologies provide excellent imagery compared with other CMOS image sensors. Our active-pixel architectures use intra-pixel amplification in conjunction with both temporal and fixed-pattern noise suppression circuitry (i.e., correlated double sampling), which produces exceptional imagery in terms of dynamic range (a wide ~75 dB) and noise (a low ~15 e-RMS noise floor), with low fixed-pattern noise (<0.15% sat). Our active-pixel sensors achieve a quantum efficiency (sensitivity) that is comparable to high-end CCDs, but, unlike CCDs, they are not prone to column streaking due to blooming pixels. This is because CCDs rely on charge domain shift registers that can leak charge to adjacent pixels when the CCD register overflows, causing bright lights to "bloom" and leading to unwanted streaks in the image. In our active-pixel architectures, the signal charge is converted to a voltage inside the pixel and read out over the column bus, as in a DRAM. Our sensors have built-in anti-blooming protection in each pixel, so that there is no blooming. Smear, caused by charge transfer in a CCD under illumination, is also avoided.
So Obin, how come you're getting smear with your sensor?
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Old July 25th, 2004, 09:28 PM   #1077
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my chip does not have this feature??
best guess..sorry ;)

my chip looks like a $20 cmos security camera when you get a really hot spot in the frame..like try shooting a scene with a lamp in the frame :(

uggghhh....maybe Steve will ask Micron about this issue
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Old July 25th, 2004, 09:36 PM   #1078
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Here's what I'm talking about Obin.

This is one of your original images, there's no smear even though you have a very hot image in the BK.

http://home.mindspring.com/~jrod/frame2.jpg

Maybe playing around with the gains screwed things up? I just remember your earlier images looking pretty good-no streaking.
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Old July 25th, 2004, 10:36 PM   #1079
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well have you pushed that a bit?

gain is worse..yes
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Old July 25th, 2004, 10:44 PM   #1080
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is this the camera with the altasens chip that everyone is talking about?... and is it really less then $2000? when will it be available? will it record directly to computer?... for the love of god... i need answers.

http://videosystems.com/mag/video_shoot_tools_26/
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