Three 1/3" or One 2/3"

R

Rednomore

New member
I have yet to read any speculation on the pickup device for the new cam. For the price, I think more than three 16:9 native 1/3" CCDs similar to the XL2 is asking quite a bit. However, does anyone think they may go the single CMOS route, say in 2/3"?

What would the advantages/disadvantages be for one CMOS over three CCDs?
 
Re: Three 1/3" or One 2/3"

Avantages:

2/3 inch size sensor - shallower DOF

Disadvantages:

A good amount less resolution due to the bayer filter that will need to be used to get all three colors from a single chip.

I'd personally rather have 3 1/3inch CCDs.
 
Re: Three 1/3" or One 2/3"

Interesting question...
My first "pro" camera was the Sony 2000 Hi8 Shoulder mount camera (about 10 years ago). It had 1 x 2/3" CCD and I must say depth of field and latitude was excellent (compared to 1/3" 3CCD cams)
FWIW

Brian
 
Re: Three 1/3" or One 2/3"

[quote author=Shaw link=board=HDV;num=1109266015;start=0#1 date=02/24/05 at 11:24:47]Avantages:

2/3 inch size sensor - shallower DOF
[/quote]

Not true. It all depends on the length of the lens. The size of the sensor/film may be a symptom, but not the cause for DOF. Or Barry's DVX book is lying.
 
Re: Three 1/3" or One 2/3"

Larger CCD's equal shallower DOF and has nothing to do with the lens. If the lens was the cause of shallow DOF then the guys who make the Mini35 wouldn't have a reason to have built their device.

But while we are on the subject of shallow DOF, a lot of people who crave it don't realise that it also brings it's own foibles and therefore a LOT more care needs to be taken in production, as well as a lot more skill with the camera. When you have a camera with shallow depth of field you would be amazed at how much you can get away with on a small chip camera, and how much work and stress it takes away.
 
Re: Three 1/3" or One 2/3"

Both of you are wrong. The DOF has to do with two things: the focal length, and the aperture setting. A smaller sensor has a smaller FOV, meaning a smaller focal length will give the same crop of an image. So a "wide shot" might be at like 5mm with a DVX, but 30mm with 35mm film and the framing would be close to identical, but since the focal length is hugely different, so, too would the DOF be. 35mm on the DVX would have the same DOF as 35mm on the 35mm, but while this would be a wide shot on 35mm, it would be an extreme telephoto on the DVX.

So, basically, YES...the 2/3'' CCD will get you a much shallower DOF because you'll need to use longer focal lengths to get the same FOV. And it would probably get you much more dynamic range, too, but not as much as 3 2/3'' CCDs and theoretically it would have less resolution due to bayer interpolation versus 3 full CCDs. But, yeah, I'd prefer it. An APC-S CMOS with a Canon EFS mount would blow my mind, though. Never going to happy but wow....that would be nice and cheap and compatible with lots of lenses. dSLRs are so close to film, yet video isn't. Irritating.
 
Re: Three 1/3" or One 2/3"

Mine, too, for sounding so pedantic. I was in a rush when I posted and the post comes off as very rude for which I'm sorry. You both had the right idea and I'm not even sure if what I'm saying is 100% correct.
 
Re: Three 1/3" or One 2/3"

Barry?

(I know, you've already covered this a dozen times on this site and in your book.)
 
Re: Three 1/3" or One 2/3"

I'd go with one 2/3" CMOS anytime! I have seen some images from HD CMOS sensors, made by those DIY-HD-camera-guys, and they're just fantastic at 1920X1080. Lot more film like than any CCD I've ever seen. Ofcourse you never know, if the big companies could screw CMOS up, and make it look just like another video...

At HD resolutions the bayer pattern is hardly an issue, just look at any digital SLR, and say they've got so bad color. And I think 3 CCD's don't give you more dynamic range. It just gets rid of bayer, and gives better color reproduction. But CMOS gives you alot more dynamic range, and a lot nicer gamma curves.

I'd want a digital SLR type HD videocamera that records to harddisks with 1920X1080 pixels from a 35mm CMOS sensor, with DV style 4:2:0 compression (or even better: you could select 4:2:2 if you wanted.) And ofcourse those 35mm SLR lenses. And I'd pay 8000€ to get it.
 
Re: Three 1/3" or One 2/3"

Satellitebunny, I would pay 8000$ happily too! It would be a killercam! There are some DIY projects getting finished now, so it means soon they will jump to the arena and it´s going to be a hell of a fight...
 
Re: Three 1/3" or One 2/3"

I think what makes the footage they shoot so remarkable is the fact that it has all of the color information still intact. I think we sometimes greatly undervalue the color compression of a camera. You wouldn't have nearly as nice of results with bayer and a 4:2:0 compression. Even a 4:2:2 would show effects of the compression.

The biggest difference between digital still sensors and HD is that digital still cameras are working with usually a minimum of 4MP. We're only talking roughly 2 megapixels with a 1080p camera. We don't have nearly as much room to play around with a bayer pattern as we would with a still camera.
 
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