Home made camera designs?

[Obin Olson]

a reply email when I asked about the micron:

I say. We have discussed this chip. A lot. Did you notice it is a 10 tap, 10 bit sensor. That is 100 parallel data lines. Over 500Mpix/sec. Even in 8 bit mode, this exceeds a 64 bit/66MHz bus bandwidth.

[Obin Olson]

my reply was:

"but can't you limit the datarate to only what is needed for say 60fps at 1280x720?"


I am waiting for a reply....

[Laurence Maher]

Okay, what about the idea of Final Cut Pro HD? It may be good enough if not alot of fx yes?

[Wayne Morellini]

I don't know much about the different video editors, I can't even remember which of the top companies announced a free standard version recently. But I have picked up Linux Format, with a section on video progams for Linux, whch I will be talking about, after I read the thing over the next couple of days, in the low cost Viper thread:

http://www.dvinfo.net/conf/showthrea...477#post181477

If there is a good freeware editor for Linux, there maybe a free Windows version, and these people might possibly get interested in supporting custom formats for new alternative HD cameras, like we are hoping for.

The advantages of a true, completely, loosless codec, is that it is easiest to add editing support for, as all decompressed footage can be edited raw, and recomrpessed, as many times as you like without generational degregaion.

[Rob Scott]

<<<-- freeware editor for Linux -->>>

There is a free/open-source video (and audio) editor for Linux called Cinelerra.

http://www.heroinewarrior.com/index.php3
http://cvs.cinelerra.org/

I played around with it a few years ago, but haven't attempted a project with it yet. It's not as mature as the commercial NLE packages, but I understand it has a fair amount of power.

[Steve Nordhauser]

Obin,
This seems like a better place to reply since you are asking general information about the monster Micron chip. Yes, you can limit the data rate by slowing the clock and doing a region of interest. The problem is that it only makes it incrementally more interesting than the 1280x720 you can do with the 1.3Mpix Micron.

We are working on a number of new cameras, due in 8-16 weeks that will address HD and global shuttering beyond what we have already. One of the reasons that I want to watch this group is to see what features the Indie market is needing.

Regards,
Steve

[Filip Kovcin]

<<<-- Originally posted by Steve Nordhauser : One of the reasons that I want to watch this group is to see what features the Indie market is needing. -->>>

so maybe someone should say what is needed...

what I will definetelly need is posibility to work in 1280x720 resolution with faster than normal frame rate - like 50 or 100 or 125 fps (i'm from pal country, so i prefer speeds which are connected with n*25fps formula, but if the option is to work normally in 25p and have 60 or 120fps it's also ok for me as long as typical frame rate for pal (in my opinion) is also possible.

i beleive that in ntsc countries the wishes are very similar but of course connected with 30/60/120 fps solutions.

steve, thank you for watching this community. it means that we are not alone!

filip

[Obin Olson]

Steve the only thing I care about on that chip is GLOBAL shutter..it HAS to be done if you want a product that will sell...I am going to use your chip/camera as a "test" for the whole idea...but I am sure I will want a global shutter camera for a final version and the highframe rate is a very good option..one that I need ALL the time for slomotion work

[Steve Nordhauser]

With most global shutter CMOS sensors there is a leakage even when the shutter is closed. On the Fill Factory, it is about 1.5% - we have seen some smearing especially when the illumination is high and the readout time is fairly slow. Will this be a problem?

The Altasens (Rockwell) HD sensor was made for this market and it is rolling shutter, but at a high frame rate. Is that an acceptable solution? The rolling shutter artifacts (time skew from top to bottom) is reduced at higher frame rates.

Also, I have been wondering, has anyone experimented with using a single sensor Bayer camera with 4x the resolution and combining four values (red/green/blue/green) into one RGB 24 to 36 bit value?

[Obin Olson]

Steve that is a very good idea...if you know how that can be done, it would solve alot of the issues that single sensor cmos/ccds have in color resolution..we need more resolution from the bayer chips. Maybe a 3mp sensor scaled down to 1.3mp? I will have to see the camera your sending me...IF I can set it to shoot 60fps and I capture ONLY 30fps this would work fine, BUT if I have to shoot at 30fps to capture 30fps and then get an image smear from the rolling shutter this will be big a problem

[Steve Ipp]

Hi, Steve, thank you for participating in this;

As for outputting R, G, B from a bayer sensor, I think it's much more complicated (I could be wrong, though) than using a single monochrome CMOS chip for the same purposes. Again, I might be proposing something unachievable with this type of technology, but totally utilizing the power of every pixel in an imager would be a huge advantage over 50 + K digital cinema cameras currently on the market. There was a good article in one of the scientific magazines (sorry, can't remember, where I read it) about Martian rover imaging system. They used a similar principle.
The way you could capture R, G, B with only one monochrome chip would be using a digital RGB filter:
http://www.qimaging.com/ccdcameras/sciind/#
http://www.qimaging.com/datasheets/RGBFilter.pdf
The resulting frames could be premultiplied by the corresponding color (R,G,B) on a target capturing system. The same soft responsible for premultiplying would then merge the frames into final stream.
In this scenario, you'd need to triple the number of frames captured on the camera head though - something like 75 fps for a true color representation.
Steve, all this theory is coming straight from pure imagination, - I never experimented with such a configuration; just hungry for pixels :))

[Laurence Maher]

Personally, I think 1080p would be the better option if possible. 720 looks good but it's nice to have all the resolution for the big screen.

[Wayne Morellini]

Hi Steve

Thanks for coming, but it does appear to be a problem as the viper thread is sort of a Sumix project (but they seem to be open as to where they get the sensor from) and this thread was to be a concise list of cameras and improvements rather that technical discussions. But I'll throw it open to this discussion even if I need to open another thread with the camera list.

Most of us are technical novices, so most of the assumptions and technical questions listed in the other two threads would be a good place to start.

About what features, I am interested in inde, documentry, news gathering, and commercals (variety of work). I think one camera can easily do all at a cheap price (compared to a professional HD camera) in higher volumes. I offer the suggestions from the Viper thread, and am interested in your SPIHT adaptive compression routine, as it appears to offer everything from true and near lossless to high compression ratios, which means people could pick what they wanted. If this was included in a independent capture to disk unit (the size of a camcorder body) connected by cameralink, or just the compression routine in the camera head through USN2.0/3.0, then the whole design, and cost, becomes simpler and cheaper. If the capture controller was also a modified Via nano-itx PC reference platform (running at 2Ghz), it could also act as edit unit further reducing cost. A seperate unit could also be used for any camera head.

The number one priority here is quality performance. So for me that includes raw footage (4:4:4 for 3 chip) preferably in true lossless compression form, but for most of us it is the performace of the of the sensor and the optics. We would all love to come close in quality performance to the big boys (your still camera market would feel the same). $5K instead of $50K (though some of us would go for $15-20K). The sensitivity, latitude etc of the camera, and trueness of colours and luminance (apart from all the other image problems), the response curves for the filtered colours, and vlow signal to niose. Maybe you could explain how to read a sensor/cameras data sheet, there are a few unfamiliar measuments in there? With low light performance, it is probably more important for live productions than for inde. I am also worried that using a Bayer filtered single chip will lower this perforamance considerably, and also sensitivity, compared to a 3 chip design, because the filter only transmits some of the light to make the pattern work, is this true? Having said that, a sensor with a feature simular to the latitude of Smal sensor's autobrite technology would be most advantageouse and go a long way to improve single chip performance (not to mention stuff like Foveon's X3 tchnology).

http://www.smalcamera.com/technology.html

For chip size people would like 35mm (though a 35mm lense adaptor is also good), I would even prefer medium format myself, but that is very unlikely. So I would say people would prefer 2/3inch and above (nothing below 1/2 inch as it might be considered a compromise, even with a good 35mm lesne adaptor design).

About super sampling single chip pixels. Is the best way to do it, to sample at each corner of the pixel and in the middle ( to minimise the variations caused by fine features moving withing a pixels zone)?

The resolutions I think people will be most interested in are 720, 1080, and SHD 8mp (pratically in that order). If a single chip could be made good enough, SHD could derive very accurate 720/1080 pixels (because of super sampling etc), and allow the camera to act as a high quality still camera. The higher resoluions are only really practical if compression is available (for true lossless of 5:1 (+), if possible.

For lenses, included adaptors to use any make of cheap secondhand slr manual/auto film lense (for 35mm lense adaptor), and dersired cinematic lenses, would be good.

A top notch 35mm lesne adaptor (if chip is smaller than 35mm), would be good (I think a simple static design could be made good enough). A image flipping mode to correct the orientation of the captured 35mm image would be good.

For the system, most people will prefer to work with nothing but a completely simple to setup and use integrated system. Unfortunately many pople would also like to use their own editors, OS/s, computers and the like. Fortunately most of this could be addressed by using a modular system that captures (if no hardware controller is used, plugin codecs can determine format), and plugins for popular editors and playback software.

Nothing else I can think of for the moment, apart from best wishes and good luck Steve.

Well guys what do you think of that list, anything more?

Thanks

Wayne.

[Les Dit]

Steve,
The filter idea all works OK as long is it's a still world ( mars , as far as we know ).
Otherwise, you get color fringing when objects move.
-Les

[Laurence Maher]

An adapter for still 35mm slr lenses, yes.