CCD's and CMOS Sensors

[mrbrycel]

I understand that this is a topic thats been gone over and over, so I'm not going to start by asking "what is the difference?". I've done a lot of research, read a bunch of articles, and I think I understand the difference for the most part.

My first question is where are all these CMOS camera's coming from, and why? And why are Red camera's still so hyped up as "the best digital film camera on the market", when they, like the EX1 are subject to so many rolling shutter issues?

I've heard people say that CMOS sensors produce a sharper image, but with high budget films like "Get Smart", "Super Bad", and many others are being shot on a camera with a full frame CCD (Panavision Genesis), and none (other than maybe an insert shot in Jumper) have been shot completely in RED, puts this argument into question. I understand that Red is amazing, and is about to come out with a 7x2in sensor that shoots 28k resolution, but isn't it still subject to skew, wobble, partial exposure, and all the issues of a rolling shutter?

Canon Still camera's like the 5D (I and II). These are amazing cameras, and I've never seen a rolling shutter issue with any stills. Wouldn't this be an issue when shooting at slow shutterspeeds? Does the 5D's CMOS have a global shutter (is that even possible?). Because I've seen quick movement on the Mark II's video that looked like extreme jello (http://vimeo.com/2527521).

I'm not trying to bash the EX1, RED, 5D Mark II, or any other CMOS cameras, but I'm just trying to figure out why CMOS sensors seem to be taking over, and how much of a plus the sharpness really is when there are so many issues to deal with. When deciding between the EX1 and the HVX, I gave up a little sharpness and went with the HVX because of this. And if I could afford a RED, I think I'd rather just buy a good 35mm camera.

 

[Anhar_Miah]

(1) Not all CMOS have to have rolling shutter, there are plenty of "Global Shutter" CMOS camera's around for example:

http://www.vision-systems.com/displ...High-dynamic-CMOS-cameras-have-global-shutter

(2) Not all rolling shutters are equal, there are many variables, the problems of skew & "jello-vision" from two different CMOS designs such as the Nikon D90 and the RED, have massive differences between them.

(3) CMOS is akin to "systems on a chip", they draw less power are more efficient and are more compact, unlike CCD 's which require alot more secondary support systems, for more details take a look at this article by DALSA:

http://www.dalsa.com/corp/markets/CCD_vs_CMOS.aspx

I'm sure there are many reasons why Camcorders are moving towards CMOS, one reason may be because the design of CMOS sensors are better suited for the Digital framework, CCDs however require more circuitary to convert from A/D, where as each PIXEL in a CMOS sensor already has all that built in and outputs a digital signal directly. Of course that does not mean one technology is better than another, each has its own strengths and weakness.



Anhar

 

[Matt Grunau]

Wow Anhar. I am going to just start each DVXuser session by checking your activity from my last login.

Yet another detailed and informative post. This question, or a very generalized version thereof, has floted 'round my dome for many a moon now.


Kewl!!!