April 20th, 2008, 07:46 AM | #346 |
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Biel,
I think you cannot really speak of 4:4:4 because every 2nd pixel has a green filter, every 4th a red one and every other 4th a blue one. With a very good debayering software, you can get about 75% of the theoretical resolution (1920*1080) out of the bayer image. But, arguably the perceived resolution (what you see) is close to 1920*1080. And the perceived colour resolution is pretty close as well. A Sumix frame would be like a 2 megapixel crop from a raw digital SLR image (eg. cropping the middle two megapixels from your Nikon 80D raw file). For me, that would be heaven. Jose Antonio, Thomas is an extremely common name in Germany ... and Probably in the rest of the world, too :-) Farhad, you said mass producing is not your core competence. What about developing a "pc-less" module that links to the cam via gig-ethernet. Design such a module and have someone else manufacture it for you. Depending on the price point, you could sell thousands - which means even more of your cams get sold. Other option, I think there will easily be 10 filmmakers on this forum ready to pay 1.5 times Scarlett price (= 4500 USD) to buy a pc-less integrated solution. That would get the first batch rolling ... Exciting times - best thread since Drake :-P, Thomas |
April 20th, 2008, 08:26 AM | #347 |
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"I'm afraid I'll have to buy an HV20...Being the Alternative Imaging Methods freak that I am that's something I hoped I never had to do."
Jose, I know just how you feel! Last year I was experimenting with the MX72 and MX73 camera heads, but realised that I wouldn't be able to iron out some of the problems in time for a film planned for the summer (of 2008). So reluctantly, I was forced to buy a Canon HV20 to familiarize myself with it in good time for the shooting. Not surprisingly, my focus went off the box cameras and onto the HDV workflow (I had to get a different NLE and learn how to use it), along with other planning for my first full length no budget project. In the meantime my work on RAM recording through USB 2 starts to look increasingly obsolete compared to the promise of this latest GigE Sumix, so maybe I've missed my chance with those cameras? Like you, Jose, I was disappointed that I had to ultimately use an interim HDV camcorder, but I'm hoping it will be my last! I don't knock the ultimate straight-from-the-camera image quality itself, because in 1080p25 mode I am impressed at the step forward compared to my previous use of SD DV. What I do miss from my brief experience with the Sumix is a chance to use manual prime lenses, and to know that what I'm shooting (however unimportant it turns out to be!) is nevertheless originated on an uncompressed (or almost lossless) format. Which, apart from the credibility angle regarding future sales opportunities, will also take reasonable post processing. In that regard HDV is just as fragile as PAL DV (it's still 4:2:0). I have collected several C-mount lenses over the course of the tests and these can be migrated to whatever system I can afford to use for a future project. That is the beauty of these modular systems, you can take things with you to the next camera (just like traditional still SLR cameras; I like that ethos). Sorry I can't contribute much lately, I'm busy with my project, but I follow the thread avidly (it's very inspiring) and hope to contribute something practical later on. All the best, John. |
April 20th, 2008, 12:39 PM | #348 |
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what is then the sampling of the camera? 4:2:2?
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April 20th, 2008, 01:15 PM | #349 |
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I took my 12A2C camera to a film shoot last week and shot some on free time in between setups. Got some dolly shots a little hand held and tripod.
I'm not happy with the way it video turned out. Looks very soft to me, even after careful focusing. I blame the TV zoom lens I was using wide open. I just bought 2 Carl Zeiss lenses, should have them in within a week or two. Hopefully they will be sharp enough to render a great image. The attached picture was not white balanced. Did not have time. |
April 20th, 2008, 03:00 PM | #350 |
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To my understanding, colour sampling is an attribute of the codec, not the sensor. You can debayer a raw image to 1920*1080, then either compress it 4:4:4 or 4:2:2 or 4:2:0.
The debayering will have interpolated luminance and colour information that is, in fact, not there. You will have some interpolated full HD image, with every pixel having (interpolated) full luminance and colour resolution. Yet, I don't think you can call it 4:4:4 or 4:2:2, because that only depends on the codec you then use to compress it. Hope that helps - please shout at me if I am getting it all wrong ;-) Thomas |
April 20th, 2008, 03:02 PM | #351 | |
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Quote:
In camera debayering? That may be another source of softness. Last edited by Thomas Richter; April 20th, 2008 at 03:35 PM. Reason: block artifacts due to me playing with monitor gamma setting - reference removed. |
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April 20th, 2008, 03:57 PM | #352 |
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Did you use laplacian to debayer? The other filters are quite soft.
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April 20th, 2008, 04:25 PM | #353 |
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It would have been the default "Bilinear" setting.
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April 20th, 2008, 04:45 PM | #354 |
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Then I think your lens combined with the bilinear filtering softened the image.
By the way, which Zeiss lenses did you buy? Where? And how much did they cost? |
April 20th, 2008, 05:05 PM | #355 |
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Zeiss VarioTevidon 2/18-90mm APO lens Super 16 c-mount
http://cgi.ebay.com/ws/eBayISAPI.dll...:B:BCA:US:1123 Carl Zeiss Tevidon 2/10mm APO lens for Super 16 c-mount http://cgi.ebay.com/ws/eBayISAPI.dll...EOIBSA:US:1123 They are not ideal, first one is a bit too long and other is a bit too wide. But I have a hard time finding good quality lenses especially super 16 c-mount. Its possible I may have paid too much. Have been watching ebay for a while and just have not seen anything I like. Finally acted when I saw this. Honestly, I know little about them. I would appreciate it if someone could comment on them. |
April 20th, 2008, 06:48 PM | #356 |
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Knowing the general price of Zeiss glass and the condition these babies seem to be in, I would say you struck a bargain.
Probably a set of carefully selected machine vision primes will be the only thing that may match the quality the same pricepoint. But that would involve so much trial and error that you would have to be very lucky. My opinion - and I am from Zeiss country ;-) |
April 20th, 2008, 09:33 PM | #357 |
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I just shot a Bilinear vs Laplacian test. You are right, laplacian is much sharper.
But with laplacian enabled, FPS falls to a maximum of ~11. |
April 21st, 2008, 04:01 AM | #358 |
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But that's just the preview. The same happens with my camera. When recording it's actually at 43fps.
You don't have to search so much for good machine vision primes. Some of the best and sharpest out there are the 5mp certified 2/3" Fujinon primes. They're also quite cheap (about $300 each). If you're looking for tack sharp images, go for them. |
April 21st, 2008, 07:54 AM | #359 |
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I'd add another vote for the fujinons. I would also like to see the schneider ones (cinegon and xenon). They're expensive which may mean they're higher quality (of course that's not always true).
Daniel, how do you gauge exposure when you are out shooting? The image has a lot of blown out areas. I found when playing with sensor heads that getting a good exposure is very difficult especially if you're not previewing via a LUT. What's the level information like in the original frame? What's the status on getting RAW frames out of the camera? You should only need simple debayering for preview and deal with the main processing later on (where you can choose different solutions for different types of images). cheers paul |
April 21st, 2008, 08:34 AM | #360 |
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how does the raw video look lime without debayering? is it possible to see a example of raw video data from the cam?
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