View Full Version : 4:4:4 10bit single CMOS HD project
Frank Vrionis August 2nd, 2005, 09:36 PM but the Sony is only interlaced.
what exactly is pixel shift? from my understanding there's a pseudo version that doesn't yield 'true' resolution - many still digital cameras use it.
and then there's the one that the XL1 used and did produce extra detail/resolution.
Keith Wakeham August 3rd, 2005, 04:12 AM Pixel shift is only something native to 3 ccd. Most ccd's are aligned perfectly in 3ccd so that all the pixels are lined up perfectly in relation to the other ccd's. Pixel shift is when one of the ccds is physicaly moved so its no longer in line. Normally the green is "shifted" so that it lies in the middle between the red and blue, so a green pixel is overlapping 2 red and blue pixels.
Lots of info in the forums, just have to search for it and it will answer questions like this.
Régine Weinberg August 10th, 2005, 07:11 AM http://www.iwill.net/product_2.asp?p_id=76&sp=Y
it, way cheaper as a full blown laptop
Noah Yuan-Vogel August 10th, 2005, 01:29 PM Obin, you have worked with the si3300rgb, right? Do you have any samples of the video it produces that show how good/bad the rolling shutter is at a 48MHz pixelrate? Could you post some, or otherwise make available to me, such video (I have some webspace available if you need). I am considering buying a camera with the same sensor but I am very concerned about the rolling shutter, but I havent even seen what it looks like to figure out what is acceptable and what is not in terms of motion artifact. I just really want to get a good idea of what we are talking about when it comes to rolling shutter cameras being bad for digital cinema. I'm just surprised it could be so unusable, micron.com lists the sensor as being appropriate for still photography (in which rolling shutter artifacts are also not acceptable) so i would expect it to be alright for video.
I am interested in the sensor in the si1300...
kyle granger? any rolling shutter artifact samples?
Anyone else who can help out with this, please let me know. I'm sure there are other people who are also interested in seeing sample video as well.
Jason Rodriguez August 14th, 2005, 08:00 PM Unless all you do are whip-pans back-and-forth, if you get the sensor to go at 48fps and then drop every other frame, the rolling shutter artifacts are un-noticeable. You won't notice the difference on any "normal" professional pan. But like I said, if you whip the camera around, you'll see it Iif you know what you're looking for), although typically there's so much motion blur on those whip-pans, that again, unless you know what to look for, you won't notice the rolling shutter.
All-in-all, it's not a problem.
BTW, you're not going to be able to clock the chip high-enough to run the chip at full-resolution and get this "drop-every-other-frame" mode. You're going to have to run at 1280x720 (windowing).
Give Steve a call over at Silicon Imaging, he can tell you a lot more about the chip, and their camera is pretty reasonably priced.
Obin Olson August 25th, 2005, 08:21 AM back from the dead? well maybe....
still working away at our FPGA design, things are going well and we have some good hard disk control from the fpga, this has been the hardest thing to get working, and now it seems it's making great progress...so all in all we are happy and are still keeping at it full on....more later
Régine Weinberg September 6th, 2005, 04:12 PM most stills lets say photo record on a flash or microdrive card.
Is there an extender that I can hook up a normal disk to emulate an microdrive. ? ?
It's for the transfer of miles of S16mm so I dream to get the frames in my computer as the S16mm material is already over 30years old and it's time
to save to an other medium.
and maybe I can get hold on a still cam that has a good film mode but even 2 gig microdrive is not much space for recording
James Mather October 6th, 2005, 08:51 AM Hi there,
I am interested and torn between all the options - The HVX200 Panasonic and the Silicon Imaging -1920HD (which seems to offer 120fps at 720p) -
Could someone please clarify for me the following:
Can the SI-1920HD be used for practical work - ie: is there a portable system available, or a firewire and can one simply attach a LCD monitor to it and go? Can you simply shoot to a firestore and post the images later with the bayer filter?
Whats the picture and latitude like? are there any artifacts?
any thoughts or clarifications would be appreciated.
Many thanks
James
Many thanks.
Jason Rodriguez October 6th, 2005, 10:08 AM Hi James,
Your best bet for sample clips, etc. is to contact Steve Norderhauser at Silicon Imaging. I'm sure he'd be very happy to talk with you about the camera.
His number is on their website under "contact". Either that or you can email him at steve@siliconimaging.com
James Mather October 6th, 2005, 10:33 AM Jason,
Thanks for getting back. I have contacted Steve but was also hoping that someone who is impartial might fill me in on the system and it's shortcomings.
many thanks
James
Noah Yuan-Vogel October 6th, 2005, 12:28 PM If it could be used straight out of the box for practical work I think a lot more people would have them. As I understand it, the bandwidth requirements of the SI-1920HD at full res and 24p (8 or 12 bpp) are pretty high (not to be handled by firewire400 or a single hard drive without compression), and making a computer to handle that data that would be portable is difficult and expensive.
Jason Rodriguez October 6th, 2005, 04:59 PM [qutoe]making a computer to handle that data that would be portable is difficult and expensive.[/quote]
Not really. No more expensive than a pricier laptop might be. I could make a very small and portable "recorder" for the 1920 that is around $2.5K (with around an hour of storage).
"Small" would be something mini-itx based, so think along those form-factor sizes and the cases for them.
I'm just thinking along the lines of how much bandwidth you'd need-it's really not that hard to get up to 120MB/s sustained, and isn't the 1920 only around 100MB/s max because of the giga-bit ethernet? If so, then it should be fairly easy to make something battery powered and portable without it costing more than the average buisness-class Pentium M laptop.
Noah Yuan-Vogel October 6th, 2005, 06:41 PM Well what i meant was $2500 computer + $5000 si-1920 = $7500 is more than an hvx200 and quite a bit more work since you have to build it yourself and there are a lot of problems in building such a portable computer system. You have a way of making a "very small" computer that contains the 3-4 3.5" HDD RAID (necessary to capture 100MBps)? I'm also not aware of many mini-itx motherboards that have pci-x (also necessary for the 200+MBps throughput of gigE in and ide RAID out). Nor do i know of many DC-DC power supplies that would be able to handle the power requirements of 4 disk drives, especially on their spin up. How about something to display on? And what about lenses (ok they can be cheap-ish, but you have to FIND one and most c-mount zooms with any resolving power are f2+). And then once the hardware is all figured out, what about software? not a lot of great software to capture on unless you can write your own (also a ton of work, and $500 just for the SDK sometimes).
Dont get me wrong, i think DIY HD is awesome, but it isnt for everyone and it isnt as simple as buying an HVX200.
jason, i dont mean to say you are wrong, but this is my understanding of what someone should know if choosing between an HVX200 and an si-1920HD as james is. Do you have some cool ideas for capturing so much data portably that i dont know about?
Noah Yuan-Vogel October 6th, 2005, 06:42 PM oh yeah and 8bit its only 50MBps which needs about a 2drive RAID, but thats still quite an undertaking.
James Mather October 9th, 2005, 04:12 AM Jason,
Steve got back to me from silicon imaging and provided me with files - I must say the images look impressive. He tells he that you own one of these - could you tell me how you find it to use for (a) portablity (it will work with a laptop? - how long is the tether) and (b) image quality. (is the single chip or the bayer filtering a disadvantage?). Also editing, is that a nightmare?
Many thanks,
James
James Mather October 9th, 2005, 04:40 AM One thing I would say is that, certainly on my computer, the footage seems a little, well....soft. Like the lens isn't quite "biting" on the focus area. Is that their lens package or a side-effect of Bayer filtering? or just the dodgy playback on my laptop (which is entirely possible).
many thanks
James
Jason Rodriguez October 9th, 2005, 12:01 PM Hi All,
First thing in reference to James:
As of right now you can't use a laptop unless you can figure out a way to use a RAID with it.
Editing is not a nightmare. It's like working with film-scans; it's the same process. The only difference is the "film-lab" is now the rendering software.
The image quality to me is fantastic-very film like. I'm seeing 4-stops of overexposure latitude above middle grey (so 4 f-stops before clip)-try that with a video camera!
Of course not only that, but because the footage is 10-bit, your ability to color correct, do looks, etc. is really unrivaled with any other format out there unless you're working with film-scans or HDCAM-SR (say from the Viper, Genesis, D-20, or Dalsa).
The Softeness has to do with the fact that the people doing focus pulling could either not keep the people in focus, or used the wrong focus mark. We were using Zeiss MkII primes (very sharp), but we were using them wide-open at T1.3 in order to reduce depth-of-field to make it look more 35mm-like (which T1.3 on a Zeiss 16mm prime is equiv to around T2.8 on a 35mm prime). When used that way, these lenses aren't digiprimes or the new Ultraprimes and Masterprimes, so the lens goes soft when wide-open.
Also softness has to-do with the MPEG-2 codec. That footage has been compressed quite a bit. At least softness compared to what I have seen. But again, the primary reason for "softness" is bad focus. We are getting to the point of 35mm-like DOF (at an equiv of f2.8), so your focus has to be spot-on in order for everything to be "sharp". That is the side-effect of wanting that 35mm-look; you're going to have to be a pro-focus-puller if you want the same "sharpness" as a Hollywood movie-and of course use the best lenses you can buy or rent, etc.
If you want to look at the footage, you will have to contact Steve at Silicon Imaging-I cannot host it.
Nathan, if you're looking for a motherboard and don't think what I'm doing is possible, please go to http://www.win-ent.com and ask for their AMD opteron embedded system.
Thanks,
Jason
Rob LaPoint October 9th, 2005, 06:43 PM Are you using the Altasens chip Jason or one of the other ones? Are you using a frame grabber or gigebit?
Obin Olson May 28th, 2006, 03:55 PM Wow, it's been a long time.
I wanted to close this wonderful thread for good.
I want to personally thank Jim Jannard and all the people on this and other message boards that helped take my dream from the drawing board and give it wings. I am a working professional now and I don't have time for the DIY projects really anymore. I learned so much here with you guys. I deeply want to thank everyone for the help and support over the years for the vision of an image free of compression and low bit depth and small sensor size. I think the time has come that we will all have within our reach products from many people and companies that will allow or creative power to blossom and spread held back not by what we can afford, but, rather what we can dream of. It's a great time to be alive in the imaging world and I would give nothing to change a thing.
Long live my digital brothers!! May your best work flow forth for each and every soul!
|
|