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 p.6 #7 · High MP Canon DSLR on the rise? | |
snapsy wrote:
I don't think anyone doubts Canon can produce one-off proof-of-concept sensor designs. The issue is whether they have the fabrication resources/investments to mass produce them cost effectively with adequate yields.
Yeah, some comments:
I've read that the 120mp sensor would not be competitive, image quality wise, with today's sensors, and that it involved some massive trade offs... What I recall was that it involved having four pixels per amp, instead of having one at each photo site. I'm not sure if that's true, however...just random crap I've heard, lol.
Now then, I DON'T believe Canon's fab tech is limiting the megapixel count at this point. Reasoning: The S100. Also, the 18mp crop sensors. I believe Canon's current fab tech can handle approx 30-45mp full frame sensors without issue.
I'm thinking that the bigger issue for Canon isn't the pixels themselves (which are excellent, some of the best if not the best in the business)...but the associated stuff.
Sony has the exmor tech (digital CDS) which involves having column analog to digital converters and other digital logic on the chip. This vastly simplifies getting great DR and eliminating pattern noise. It also lets the analog portion of the chip (and maybe the whole thing, I don't know) run at a much much lower frequency...that further makes things easier...
The D4 chip, while not having digital CDS, has the analog to digital converters on the chip, as well. How many of them there are, I have no idea. While not as great of DR as the exmor chips, it has large DR advantage over the Canon method. It makes it easier to get that great DR. I dunno who makes the D4 chip, some say Renesas, I bet it is Toshiba, but who knows. Toshiba has great experience with mixing analog and digital logic on one chip.
Samsung's new 20mp sensor is the same way, on chip ADCs, and I believe, around 13 stops of DR at base ISO (similar to the D4). Samsung also has a lot of experience mixing analog and digital logic on one chip.
As far as I know, Canon has no experience mixing analog and digital logic on a sensor. Maybe someone has some inside info on this, if so that'd be awesome. Putting the analog to digital converters on the chip would make getting the higher DR a lot easier. Let's face it, a 45mp sensor with pattern noise and 11 stops of DR is not going to cut it. I believe Canon knows this. Can Canon's process handle mixed logic on a sensor? We don't know.
I believe Canon COULD get great DR out of their existing analog output sensor tech. However, it would probably cost a lot more and require real tight QC. The more read out channels you have the harder it is going to be, too. How many read channels are they going to need to get decent FPS from a 45mp sensor? How many will be needed to deliver a decent live view experience? Medium format digital delivers great DR, but their chips run slower and read out is much slower.
I'm sure Canon will find a way to deliver, though, one way or another.
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