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November 25th, 2005, 08:46 PM | #1 |
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My little DIY camera project
I thought I'd post some of my progress on my camera project. I mentioned it in other threads a while ago but not in much detail. I wanted to contribute to this forum since without it I wouldnt have been able to do any of the cool stuff ive been playing with and I'd probably know about half as much about cameras.
I'm working on building a cheap DIY HD camera based on the sumix M73 camera which uses the same micron sensor as the si-3300. It made sense to me since when it comes to box cameras, its just about the only one that can get good pixelrates (up to 48MHz) and stream it over an inexpensive interface (USB) for under $1000. Plus any other manufacturer charges for the software development kit ($500 usually), wheras sumix's has a pretty nice easy to use c/vb api. I'm developing software in VB.net and vb6 (im no programming pro, but vb is so intuitive its quite easy to learn as i go). And I have a small intel shelton embedded computer board that was cheap on ebay, passively cooled for quiet operation and low enough power to use 12v nimh batteries through a fanless dc-dc psu. It remains to be seen how much the limitation of a 1GHz CPU will effect what kind of video I get. At very worst I will be using 1024x576 (2048x1152 subsampled) which is still almost dvcprohd res and would make for nice sharp dvds, because I know that this little computer can display that at 24fps with only about 45% cpu usage leaving enough for writing to disk. At best I would go for about 1600x900, which works over usb and seems ok on my 2ghz AMD cpu (my development box) except for its slow shared harddrive. The trade off is that 1024x576 uses the whole 1/2" sensor and 1600 uses a little more than a 1/3" area. Of course I'll probably end up being lucky to get 720p on the little slow intel board. Really, using usb works out since with a max pixelrate of 48MHz, to reduce rolling shutter I wouldnt want to use more than 30MBps of the 48MBps coming in anyway. So as it is im waiting on a lot of parts for the ABS plastic housing im building among other things. I'm going to morocco in 2 week so dont be too surprised if it takes me a while to let you guys know how it all comes together in the end. Here are a few pictures of/from the project (sorry all the pictures are of me, but when you are running a camera tethered on a 4ft usb cord theres not a lot else to take pictures of): http://community.webshots.com/album/490353121bgxuMK youll notice some have no color or very little color, thats because they were mostly taken without UV/IR filtration. my B+W UV/IR blocker should show up soon. Let me know what you think or if you have questions. |
November 27th, 2005, 12:37 AM | #2 |
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It took me about a day to figure out what you are doing. Now, I am very impressed. My questions are this:
How good is the light sensitivity of the camera? How noisy/clean is the CMOS sensor? What file format are you converting the video? This thing could be a great base for a 35mm adapter camera. Imagine, 35mm lenses with great DOF and High Definition for under $3000. If computers get faster, this system would only get better and cheaper. |
November 27th, 2005, 04:45 AM | #3 |
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Wow I wrote a nice long reply but dvinfo logged me out so i lost it when i tried to send it.
To sum up, though, the sensor isnt great with light sensitivity, but it has a lot of pixels which make for a lot of flexibility with frame size/resolution. The other micron sensor with bigger pixels gets better light performance but I hear has smearing problems. at high gain, the sensor has a lot of vertical fixed banding noise which comes out in photoshop subtracting a dark frame but I dont know how practical that is for video (I regularly shot static grain on a 35mm adapter for subtraction in post for a short I shot, but never ended up really being able to use it for various reasons) The program stores raw bayer to a dedicated harddrive (realtime encoding wasnt within my processing power), bayer video can be parsed and viewd in my program and converted to any avi format. I prefer sheervideo 8b 4:2:2 since its faster and gives better compression than any other lossless compressor I've tested. Should be even better when its done with beta. I figure 4:2:2 should be plenty to store video thats from a sensor that is basically physically 4:2:0. It's all costing me about $1700 including lenses, mattebox, rails, 7" lcd, etc. Might need to invest in a computer upgrade to get more data/resolution. Probably a low power amd venice or palermo, but microatx isnt that small and that will all mean using (loud) fans and less battery life. If all goes well I will shoot test footage in morocco in 3 weeks and I'll be sure to post what i can. |
December 8th, 2005, 12:32 AM | #4 |
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Oh yeah check out that photo album again for pictures of my camera housing and $20 mattebox and $20 rod support system and the camera housing. I havent had the chance to take/post pictures with my new lcd mount and handles or with my nice new UV/IR blocking filter (much better color now) but I will try when im not so incredibly busy.
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December 8th, 2005, 05:40 AM | #5 |
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Hey, it's turning into a camera package! Nice work. What is the black material used in the case and rod support? How do you keep the pieces that clamp onto the rod support in place? Are those hose clamps glued to the crossbar pieces?
I really need a rod support and battery box platform, so this post is perfect timing. |
December 8th, 2005, 05:48 PM | #6 |
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Strange that this isn't a huge thread. It's very much over my head, this whole thing, although it sounds very simple. So how much does the sumix M73 cost?
One other thing, it seems that it wouldn't be suited to use in combination with a 35mm adapter when it comes to light etc.? |
December 11th, 2005, 05:33 AM | #7 |
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Yeah I sort of expected more interest, but I guess the whole diy HD has died down a lot perhaps largely due to the introduction of new, affordable HD cameras.
To answer your question, the m73 camera head cost me $800. As for 35mm adapters, I agree about the relatively poor light performance making it a bad candidate for such an adapter, but then again, somehow I just got an amazingly sharp schneider-kreuznach (sp?) 17mm f0.95 c-mount lens on ebay for $1+10sh which on a 1/2" sensor aint too bad for getting shallow DOF AND better exposure. in theory it is pretty simple, only problem is its not simple and its gonna get complicated if i have to start moving away from sumix's easy to use functions for some of their undocumented ones or even programming registers myself since some of their functions can be lacking for my purposes (their fps setting function doesnt care much about minimizing rolling shutter or necessarily even keeping framerate consistent or accurate, for example) oh yeah and if anyone knows how to set windows at one resolution and scale it and output it to a vga monitor at a different resolution (some scaling utility or something?), i could really use that since the 7" lcd i got that said it could take 1600x1200 actually cant and i dont have the time to return it. |
December 11th, 2005, 06:20 AM | #8 |
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I see you are building a portable PC for the camera, but I was also wondering, if you could (if the right software is there) record the m73 to a laptop, or maybe such a tiny new mini-Mac?
Anyway, if I was wearing a hat, I would have taken it off. Keep it up. |
December 11th, 2005, 10:29 AM | #9 |
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I considered that, but first of all laptops and mac mini's generally have 2.5" hdd's and usually not more than one (kinda need a dedicated drive to keep all the disk writes linear and uninterrupted), making it tough to get the disk write performance required for raw data and high resolutions (they usually cant sustain much more than 10MBps, maybe 20MBps for new 100+GB drives, and proabably a lot worse if you are sharing it as a system drive). As for the mac mini, sumix only has drivers for windows and I only know how to develop for windows anyway (and hardly even that but im learning :P). Plus i like that it all goes together and is modular, on a laptop id be paying for a nice screen that cant move around and might be pretty unusable when shooting handheld.
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December 11th, 2005, 03:31 PM | #10 |
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Of course. I didn't mean to ask why you weren't using a laptop, that's absolutely clear.
I just wanted to know if other people could give it a try (with a laptop)without having to know how to put together such a difficult thing you are building. |
December 11th, 2005, 04:20 PM | #11 |
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Oh yeah its certainly possible and i imagine for certain uses even better. Perhaps with a firewire or USB (on a separate USB bus) hdd, or even on a notebook harddrive. Actually the limitations on processing power and hdd performance might be pretty well matched on a notebook hard drive and a slow system like mine which seems to be maxing out on CPU power displaying and capturing about 15MBps worth of video simultaneouly which is unfortunately quite a bit lower than my target bitrate but thats what i get for thinking a passively cooled 1ghz intel with no cache would be enough. If I perfect the software/prototype I'll eventually also upgrade the computer.
But thats the beauty of a diy camera, you dont need to get a whole new camera to get a better camera, just upgrade the poorest component. |
December 11th, 2005, 04:49 PM | #12 |
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Noah, congrats on trying to put this together. It is a lot of work but it definetly can be done.
Some people might feel that these threads have resulted in nothing but failure. That doesn't hold true at all IMO. Reel stream started here, and The Drake camera was shown here, my project and Obin's started here and are both now something that isn't ready (but doesn't mean that they have been given up on at all). The reel stream is successful and people are getting it modded. The Drake camera works but never went commercial, and it still might. So the primary groups that were here are either working on stuff that is (no offense) to complicated to be discussed here or have not gone commercial. Things at embedded hardware and circuit levels so it makes it hard to discuss things here. So I'm keeping an eye to this too thread. So just a suggestion, their was someone who mentioned a cameralink card with onboard scsi controller. This would eliminate the need for the computer to do the storage processing and you just need to program the software to preview and select when to write to disc. Just a suggestion.
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December 11th, 2005, 10:27 PM | #13 |
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yeah i recall hearing about various cameralink cards that would do such things, as well as ones with built in ram slots for solid state recording to many large ram chips. Of course all these, including cameralink even at its most basic level I deem too expensive for my project, my entire computer section cost in the range of $500, a simple pci cameralink card costs about that much by itself. Those special direct recording solid state/scsi cameralink cards i imagine cost in the range of $1000-3000, not to mention cameralink versions of cameras may cost more and have difficult (and expensive) programming interfaces.
I think such options are great solutions but thats not what im trying to do. If i had $5000 to throw around on high end hardware, it probably wouldnt feel right to use homemade $20 matte box, $20 rods, and $40 case on it, and oh yeah i might actually have bought some tools instead of putting it all together with my uncle's screwdriver and hammer and a drill i borrowed from work for a day :P |
December 12th, 2005, 06:07 AM | #14 |
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I'm sorry, I thought you were using the SI-3300 in cameralink. Forgot it was the sumix M73. That is definetly my mistake, sorry, I shouldn't have been so careless suggesting a higher end cameralink card when your not even using cameralink.
Didn't realize you were so far along, just checked out you webshots and you've pratically got the whole camera setup built. Congrats on that. For people who haved seen it check out the link at the top of the thread.
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December 12th, 2005, 11:47 AM | #15 |
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I'm just writing out of curiousity...but which cmos camera heads (usb) are suitable for these projects? I see allot of these cameras for machine-vision and medical applications etc.
I know the Drake thing has an IBIS5A with stunning results, but that's not usb is it? |
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