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http://obin.weet.us/outdoors-1.wmv
No, but we would also not shoot with a 35mm ARRI this view. Obin, i think there is a differently "look" we need. You compare all images with a normal video camera. But i dont want video look. I love cinema, and so i love your earlier images. But my main problem now is the rolling shutter -->>> I don't care what you would shoot with a 35mm Arri...that is NOT the point. The point is this thing has bad artifacts in the shadows, period. end of story how you can talk about my SHOT is beyond me.. As if that shot has any meaning beyond showing dark artifacts...what gives? I don't compare this camera with a "normal" video camera, how could I? I have thought about it and the idea makes me sick..this is so far BEYOND a "normal" video camera it's not funny at all. So Rai, take it easy, I am hear to HELP you. I could just as well design a camera system like Kinetta and NEVER talk with you about it or anyone on the boards..this is my decision to SHARE and I don't like it when people start giving an attitude in here..it's not worth it..so don't even start. If you want put me on your payroll I am happy to send you pictures every day and work all the time on this and NOTHING else. Until then CHILL OUT...Shoot your movie on FILM and WAIT a few months for my camera or buy a Kinetta.. I would NOT recommend you use anything on this board for a FEATURE that you have pressure shooting, not until we have a better workflow for all the HD stuff. not bad Ben, but I would still want to start out with the MOST color I could for that much more range when I "push" it around in Combustion |
Yeah, no doubt -- I'm just trying to show that it's not as dire as it seems...
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Hey guys,
I did some dynamic range tests with those MacBeth charts. Anyways, what you see there, after gamma correction, is just about correct exposure since the third square from the bottom is middle grey, and should line up with around 50% grey, which it does when gamma corrected. So the good news: These cameras are uncompressed The bad news: You aren't even close to the Viper or even the F900 (newest /3 upgrade) in dynamic range. If you'd like to see a Viper test chart, here's one, and it spans 9 1/2 f-stops (there's another 1/3 of a stop in the highlights according the the cinematographer who shot this, so almost 10-stops total for the Viper). These Macbeth charts are only showing maybe around 5-6 with around 2-3 stops over 18% grey cause the shadows look really bad and the highlights clip awefully hard. Now it could be the lighting not being even enough, but from the looks of things, you're not getting something for nothing. There's still a reason the Sony F900 and Viper cost $$$$ :-) http://home.mindspring.com/~jrod/ViperChart.jpg This is a test from the F900 with the film gamma curves. I've applied a reverse log-lin LUT on the image, and as you can see here you're getting around 6-7 f-stops (4-stops over, 2-3 stops under), although I've crushed the shadows down a lot, so there's another 2 fstops there for a total of 9. And I've done other tests witht the F900 and gotten 9 legitimate stops out of it, so this is about right. http://home.mindspring.com/~jrod/F900Chart.jpg Quote:
The Kinetta has one of the finest minds in video hardware design behind it, as well as a number of top DP's from the ASC, BKTS, and Jeff himself is a Sundance award-winning Documentarian and has filmed with some of the top names in documentaries such as D.A. Pennebaker, etc. There's A LOT more to the Kientta than just a chip with a PCB and hard-drives attached to the back. And as I hope you check out from the Macbeth charts above, you need to be getting a lot more out of your chips before you're on the scale of the Viper or F900/3. |
Can't wait to see a Kinneta sample. I wonder why they are so shy about posting one? I commend Obin and Ben for posting numerous clips on here ! This is all a learning process, and yes, sometimes there are critical comments. From me as well. If my comments seem criticizing sometimes, pleas understand I'm talking about the images, not the efforts of the folks shooting them.
I noticed Steve had a Dollar bill in the back there, on his new test shots! ( My Idea to use that as a res chart that is easy to get! ). Any chance Steve shot that as well, I'd love to see it. I'm wrapping up an engineering class I'm teaching this summer, so I'll be able to spend a bit more time on projects. I'll shoot that $1 on my JVC HD10 real soon. As well as some 35mm lens tests on the same camera. Cheers -Les |
The JVC Altasens camera, posted before, claims to fix image skew in panning by directly accessing pixels, I thought this was a global shutter methord?
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Provide you pack, and frame buffer, Gigbe and firewireb (and even guarantee 24fps capture on USB2) has plenty of bandwidth for single chip (3chip if you compress). I guess I have been getting too caught up in the cameralink vs HDSDI cost savings, and SHD/UHD possiblities, but you're saving hundreds on the capture card. Gigabyte sent me some email saying it's new motehrboards has Firewire B, so the firewire revolution is continueing. Quote:
Still if Steve can tell us how gain affects range, we might be able to get a couple of stops more. Quote:
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Resolution targets:
Money is one of my favorite targets for testing cameras and lenses, although newspaper isn't bad. Here is a test image from our monochrome SI-3170: http://siliconimaging.com/Samples/3170M%20Jackson.jpg Rob on SI-1920HD single chip: Yes, first pass is a single chip. We we can handle 300MB/sec, we will consider a 3 chip. We are not adverse to using larger format lenses if required - we have a camera coming out with a big sensor soon (too slow for here) and will either go T2 or F mount on that. You are correct though that the optical path through a prism is too long for most c mount applications. |
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Jason if we use the Altasense then our camera will take the same picture as the Kinetta! I would not put the Kinetta on such a high seat ..it will be great I am sure but nothing is "GOD" anymore IMHO...even if we want it to be it will fall sooner or later because in a world of? what 8B people or so it's hard to have an original idea for long ;) anyway the Kinetta has nothing to do with my efforts..I had no idea it was a pcb camera untill after I started on this quest..
Although if this effort fails I guess I know who to give my $60,000 too!! Do you have any idea how much $$ Jeff has spent sofar on R and D for that camera? Steve N: Will we get a better dynamic range from the 3300? if Jason is right 4-5 stops is not that good |
Wiki
Just a quick update -- I've had to lock down the ObscuraCam wiki. Some jerk went in and deleted half the topics. You can now read the "static" pages, but if you want to edit you'll need to e-mail me for a un/pw.
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Obin,
I have no idea how much Jeff's spent so far. One thing though is that image quality is not the end-all-be-all. You have the bayer demosaicer, all the electronic in the camera, portability, durability, etc. Have you read his article in Showreel Magazine (it's on the website in PDF format)? He's got a lot of really good ideas, and it's in a very nice compact, cameraman/cinematographer friendly package. Great OLED display, RAID 3 hard-drives, and to boot he's got one of the pioneers of video equipment design making the electronics for the thing. Anybody can shoot film from Kodak and get the same "image quality". There's only one Arri or Aaton though. |
Re: Wiki
<<<-- Originally posted by Rob Scott : Just a quick update -- I've had to lock down the ObscuraCam wiki. Some jerk went in and deleted half the topics. You can now read the "static" pages, but if you want to edit you'll need to e-mail me for a un/pw. -->>>
Typical, hope you have a backup. |
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Steve,
The flower image from the 3170 is overexposed.It isnīt a good test image.The whites are clipped. The dollar image looks amazing to me, I canīt see noise. Also when I work with video I never let whites to go over 90 %. Could you test its sensitivity? Get a photometer, shoot a grey card or a TEC (TEC should give you a final image after gamma correction and the rest with these values: 4% for Black, 50% for Grey and around 97% for White) Also If I'm not wrong, I guess the values for a ĻnegativeĻ should be 4, 36,72.... Obin, I'm curious about your pedestal settings, how do you manage them? In IRE scale Black for NTSC is 7.5 and for PAL is 16... I ask this because on the images that show the streaks I see washed out blacks... Thank you for all your work and courage :) |
I get a kick out of terms like pedestal and IRE black, when they are applied to computer images!
They even use "Mhz" to talk about resolution sometimes! -Les |
@Les: I get a kick out of terms like pedestal and IRE black, when they are applied to computer images! They even use "Mhz" to talk about resolution sometimes!
Pedestal and IRE black, along with IRE white values, are totally and completely irrelevant with these cameras. It is much more like exposing a negative. The "pedestal" is controlled by an "offset" control (in my case, two offset controls -- one for each G channel). You generally set your main offset once, to the black level of your liking, and then adjust the other offset every once in a while to make sure it's matching up with the first offset. It's relatively easy to overexpose if you try to make the on-screen image look "normal." Like Jason has mentioned many times, the raw image should look pretty dark. Only specular reflections and bright highlights should be approaching the max value (be it 255 or 1024 or 4096). I adjust my camera so the brightest thing in the scene is just under 255, so I can be sure that I'm not clipping them at all. In post (or on the camera hardware, at least partially), you apply your gamma and move your white points down to increase exposure. This is where 8bit starts to fall apart. You really need at least 10 bit to make these corrections gracefully. After that, you increase the chroma/saturation however you want to do that, and then you should have a fairly "normal" looking image. This is pretty much what consumer cameras do internally. Mhz has been used to talk about resolution on some HD cameras, but I think its a poor benchmark. The idea is, the more pixels, the faster the sensor/camera's clock has to run to read them all out. So rather than say 2.1 million pixels, you say XXmhz. The problem is that no one but engineers care what clock rate the camera is running at... People just want to know what the final resolution and frame rate is. :) - ben |
Rob: I would be very interested to know what problems there are with standard lenses with a 3 chip. The only issue that the prism manufacturer discussed with me was the length of the optical path vs the back focal distance.
Juan: Can't do that right now - I have to work on the 1920HD to get it out. The Jackson shot was taken with very good lighting and gain and offset correction. Obin: I guess if you can saturate the sensor without smears, you can get better dynamic range by shooting the full range but they are both 10 bit cameras. |
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Well, I undertand that we are not working with normal video, but for film the IRE standard is also used.TEC from KODAK gives its values in IRE scale so I stick with that.
When you go from digital to film you use TEC, too. Anyway if it isn't correct it works very well.... :) |
So that is why they cost so much (as well), puts a whole new spin on keeping single chip.
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4-5 stops is like a bad video camera
You can see in the images I posted what 9-10 stops looks like (Viper). |
Jason I don't think I am getting 4-5 stops...how on earth could I shoot that windos shot and have the inside room with NO lights and the outside in the range it is??
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I donīt know what time of the day it was, but that shot wonīt give better results on 35 mm...
I still think it isnīt correctly exposed (nothing personal Obin, just my point of view).I've been playing with the 16 bit tiff in Combustion with no success, shadows too deep and highlights too high....:( |
That's what was in those MacBeth charts-about 5 stops.
You could do some comprehensive tests yourself, check out the shot of the different charts with the Viper. In that shot, they set up three charts with three levels of light in between with a light meter setting for each. The one on the left was lit 3 1/2 stops lower (according to 18% grey), the middle was at EV 8, and the one on the right was a little over a stop hotter ( according to 18% grey again). That would put the white chip on the right hand side one stop hotter than the center white chip, and the black chip on the left hand side is 3 1/2 stops lower than the black chip in the middle. Because you have a 4 1/2 stop lighting difference between the dark and the light, and the black chip is another 2 stops below the EV 4.6 of the dark side, that gives you 6 1/2 stops. On the highlight side you have another 3 stops above the middle grey chip, for a total of 9 1/2 stops in that scene. That's quite a bit of dynamic range. You can try that test too and see what you get. That should give you a pretty objective measure of what the chips can and can't do, instead of thinking you're getting a lot by shooting hot windows. |
Steve, is there a camera with global shutter available?
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Rai:
At the resolution/frame rates that are being used in cinematography, we only have IBIS-5 cameras - the SI-1280F in USB 2.0, camera link and gigabit ethernet. If Ben gets everyone revved up on IBIS-5, we have a 12 bit version using an external A/D for faster rates and lower noise. The only other global shutters we have are a VGA at 250fps and a 2Kx2K large pixel, 15fps (2Kx1K@30fps) MONO ONLY. Gosh darn. Something like $1M to get a color mask done and fabbed - the sensor company has no plans to do it. It would make a bodacious 3 chip camera though...... We have to see what the image quality looks like. It is in layout now. |
Steve,
Could you tell me what's the usual way you use to remove the FPN from a sensor? |
Juan, what does a 2 chip camera get you? Would that be 2 bayer-filter sensors, each recording at a different exposure setting in order to form 1 HDR image? Clearly there's no way to get color from 2 b&w chips, so you must be talking about HDR from 2 color sensors...
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Jason your right! and untill we get our software running IN COLOR I will wait to test...
I have an update today that has the software PREVIEWING in COLOR! awesome...but the framerates are very low when I hit record...so I will give my coder a bit more time to get that up ;) |
Hey there,
Just thought I'd put something out there. Just wondering if there was a 'cheap' compatible camera available that could capture at say, PAL resolution (or slightly larger). When I say cheap I mean at least 1/4 of the cost of the HD camera you are looking at here. There is a 640x480 camera on the site but due to the high framerate it gets, I'm assuming it's still expensive. I'm pre-empting the modularity of the 'Obscura' system. The idea that you could cheaply use the same software etc. to capture video comparable to higher end prosumer cameras (eg XL1) then be able to upgrade to the HD camera with little pain. The idea of being able to get a progressive scan system with the ability to swap lenses for $1000+ US, plus the abilty to upgrade to HD for the price of a new XL1 would be attractive I think. Is there such a camera and would the stuff learned here translate over to the said camera. Raavin (Use my handle to save confusion with the other Jason) |
Raavin, the PAL or NTSC-res cameras I've looked at haven't been much less expensive than the HD camera I'm using (which was around $1000). It seems that 720p is kind of the "sweet spot" pricing wise -- more resolution makes the price go up very quickly, but less resolution doesn't cost very much less.
Steve might have more info on this, but I've seen a lot of NTSC-res cameras that are actually much more than $1000, and I'd imagine that the average price would be at least $800. Basically, if you're going to go to the trouble of doing all this just to get an image, why bother with SD? - ben |
Sorry to be a pain Ben, but what camera are you using?? I just got through all of the posts after 3 days and it's going to drive me nuts. I thought the camera setup that Obin was using was around $4k US.
Here in Australia, a new XL1 is around $8k plus AUD and a lower range 3CCD camera like the XM2 is still $4.5k. As long as it was under $2k I think there would be heaps of interest. That's as much as a reasonable handycam. Raavin |
Raavin,
I'm using an SMX-150c from Sumix, which operates over USB 2.0. For right now it's 8bit at 1280x1024, up to 27.5fps at full resolution (and 40fps at 1280x720). However, the company is developing new firmware and software for the camera to enable it to do 10bit -- possibly 10bit log from 12bit data. Anyway, it costs around $1000. I think Obin's camera is actually around that price too -- it's just that his camera necessitates the purchase of a CameraLink PCI board and some expensive software (if I understand correctly). Although he's working on his own software too. If Sumix can get 10bit out of my camera and address a few usability issues with the software (they're working on it), I think it would be a great alternative to prosumer gear like the XM2 for certain projects. Even at 8bit, downsized to DV-resolution, the images I'm getting far surpass what you can get with prosumer cameras. Juan, that sounds like an interesting setup, but it would necessitate the creation of an alternate bayer filter for the sensor, and from what Steve just said, it sounds like that's in the US$1,000,000 range. A bit out of my league. :) - ben |
"http://obin.weet.us/color_8bit_cinelink.jpg
---a capture with CineLink...opened the RAW file in photoshop convert to 8bit and apply a bayer filter plugin Original RAW file: http://obin.weet.us/Rec00001.raw Ben can you write a plugin that allows AfterEffects to open that RAW file and apply a Bayer filter on it? I think it's a 10bit file...not sure..should be the same as the last RAW file I posted |
If you can get it into AE, you can apply my filter. But I've never coded an import plug-in before...
It should be relatively easy to write a command-line converter for your RAW files. All you need to do is slap a 16-bit TIFF header together with the data, and you've got a valid 16-bit TIFF. Could be coded in an afternoon... |
want to take a stab at it Ben...it would help out this project a bit...;)
I am NOT a code writer ;) Or maybe Scott? what about a format that is native 10bit? or is the 16bit tiff just as good because the extra bits are zero's so no extra space is taken up?? ? |
BTW, really nice image!!!
Also your last outdoors clip looks really good.There are detailled highlights and shadows.Well done Obin!! |
Hey Obin,
What bayer filter plug-in are you using? |
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ok here is a raw convert into BMP 8bit...what is causing this streak? it's not the sensor it has somthing to do with timing I think...ideas anyone? Rob?
http://obin.weet.us/streak.bmp |
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