Balazs Rozsa

In some of its cameras Fuji uses a special CCD which has photodiodes with different sensitivities. The camera combines the results from the two kind of photodiodes and produce a high dynamic range image (they claim only 2 extra stops). I think this is a much better way to increase dynamic range than trying to increase dynamic range of the individual photodiodes. At least after a certain point. Because now you probably want to use all your photodiodes to make the resolution of the chip as high as possible. But as the number of pixels increase on sensors, at some point you will choose to increase dynamic range rather than resolution.

Three 12MPixel 60x40mm CCDs if we talk about the same camera from 2001. Specificationwise it is still one of the best. They were considering it for for movie making as well. http://www.arri.com/infodown/news/0309_e.pdf

A few years ago I read the D20 can output the full data from its 6Mpixel sensor (internally downsampling to HD was the other option). I haven't heard about that since then. Maybe they gave up on that feature.

That is correct.

When you shoot 1080 and 720 you have a choice of using the full sensor area or only the middle section of the sensor. When you use the full sensor you have 35mm DOF but you are limited to a maximum of 60 fps. When you use the middle section you can have a maximum of 120 fps.

If it was only the chroma information, they could unite these pairs into smaller pixels. But that would halve the vertical luma resolution to 1080 which is only the native resolution of the output. Now without uniting they can use downsampling to generate the output that will give you a sharper luma image. But yes, the chroma resolution is about equivalent to what you could get from a 6 Mpixel Bayer imager. But chroma resolution doesn't need to be as high as luma (still it is quite high resolution considering it is downsampled from 6 Mpixels).

In the Kinetta one 1.8" 40MB HDD records 110Mb/sec sustained (50g iPod HDD).

Could you please tell at least the basic idea behind this statement? Look at the Fuji extended dynamic range sensors. If you are willing to dedicate half the number of your pixels to highlight aerias, you can extend the dynamic range. That is a possibility for the future, when increasing the resolution of the image will not be as important as increasing the dynamic range. Or look what happened to CMOSes. A few years ago they were very noisy, now the Canon digital SLRs have quite low noise. Every time you can add one more transistor to a CMOS pixel cell, you can build one better amplification circuit with less noise. And miniaturization allows that. Sure the fundamental workings of CCD and CMOS imaging devices did not change too much since their invention. But they are steadily getting better. Not big changes, but noise, dynamic range, resolution getting better steadily.

Jim Murdoch wrote: "It's going to take more than "another" generation too; CCD and CMOS image sensors have been around for 35 years now, and this is about as good as they're going to get. The laws of physics can be terrible curmudgeons sometimes." Do you mean they will not get better from now on? In the last 35 years they have been improving nicely, especially in the last few years. What laws of physics would stop them getting better now suddenly?

The reason ?10 years ago they were predicting that soon ? and look after ten years still nothing happened? sounds good. But, if somebody was predicting 10 years ago that movies would be shot digitally soon, he could only hope that big companies like Sony and the like will come up with a new big cheap tape mechanism that can record 4K or 8K images (which was unlikely). Or he could hope that movie makers will be happy with 2K resolution (which was obviously not the case). Now the situation is different. Computer technology is getting near the point where it will allow the recording of very high resolution images economically. Please! Theoretical limits are much higher than what is available now. And there are new technologies like laser interference volumetric storage and who knows what else. But of course you cannot base your prediction upon these vague things. Instead just look what the current hard drive manufacturers are doing and saying. The technology you will find in the shops in the next three or four years already exists in the laboratories. And even after that they have a fairly good idea how they will increase storage capacity. Capacity is so high already that you do not need to go that much far in the future to see how computer storage will allow high quality video capture cheaply. 10 years ago a 1GB hard drive was considered a really big hard drive, you could not even dream about recording any kind of video feasibly. Now we are very close. Ten years from now storing the video on hard drives will not be an issue. But this is the first time we can say that. And this time it is quite easy to see it is true.

If you consider on camera recording from a purely storage capacity point of view, the Kinetta shows well what can be techonologically achieved. It is 6.5kg with battery and a hard drive magazine and it records 1.2Gb/sec into a fault tolerant raid array. At about 1.9Gb/sec you can record uncompressed 2K 10bit 24fps. That surely could be put into 10kg. And it uses the old 40GB drives, the new 60GB drives are already on the market. So I think uncompressed 2K on-board recording is very well within reach. When will be it 4K? Based on the increase of storage capacity in the last 15 years (which is about a steady 1.8 fold a year), the jump from 2K to 4K will take slightly more than 2 years. The jump to 8K another 2 years, and the jump to 16K another 2 years and so on. Of course it is possible that we are just at the point where the storage improvement will slow down and then we will need maybe 10 years for 16K capture.

Thanks for the info!

Where do you get this information? I could only find that the SRW1 records in both the 4:2:2 and the 4:4:4 mode at a rate of about 440 mbps and the 880 mbps mode is used for recording two streams of video. Balazs

Yes, the Genesis CCD has 12.4 Mpixels, but the camera output is only 2 Mpixels. The Dalsa gives you 8 Mpixels. Balazs

I think the difference comes from the fact that Dalsa specifies its ASA sensitivity for 8 megapixels while the Genesis is specified for 2 megapixels. When the sensor sizes are about the same. Balazs