CMOS vs. CCD sensors(XF 300) vs. (XH A1 series)

[Roger Lee]

I'm sure this is widely documented but still I'm curious.

The XF300 comes with 3 CMOS sensors. The XH A1 series with 3 CCD sensors. Both sets of sensors are the same size.

How does this translate to better image? Anyone have a real world example?

Bottom line, I'm thinking the difference between CMOS and CCD sensors is one of the big selling points for the XF300 over the XH A1(s) and the justification for one camera costing 2 to 3 times more than the other.

Thoughts?

[Peter Manojlovic]

Roger, i'll let the others chime in, and what i tell you is totally from observation, and a quick talk from a Canon rep..

These two cameras are completely different, and same only in colour and maybe similair button layout..

But the XF300 is a 1920x1080 full raster CMOS censor, with 4:2:2 colour sampling.
My XHA1 outputs 25mbps to tape, whereas the XF300 outputs 50mbps to card...You must realize, there's twice as much data being written.

The CMOS sensors work better in low light..And yes, there are people who claim that Canon should've gone with bigger censors, but the rep from Canon says that if you go above 1/3 size, then you run into issues of rolling shutter..

I've got an XHA1, and not matter what i do, there's no way it can come close to some of the sample pics on this forum...

[Roger Shealy]

I think its also fair to say that the XHA1 is encoding to a much less efficient codec (.m2t) and the actual data storage of the 300/305 is probably more like 4 times more dense. The A1 is still capable of great images but you will always fight CA on high contrast, noise in less than moderate light, and tape xfer. I love the A1 and those who know how to shoot can clean the clocks of less talented shooters with the latest fare. When the shooters are equal, the A1 is at a serious disadvantage from data, optics, and workflow. I tried to find a well done comparison of the two I saw several months ago from Japan where they staged the two cameras side by side and ran various tests on a model in a range of difficult situations including green screen work to show the differences. Unfortunately I couldn't find it for you tonight.

I think the bigger question for a lot of us doing creative work is whether to invest in a big, expensive, small sensor camera at all or go with something like the Panasonic TM700 for coverage shots (and amazingly good primary shots too) and mix with a DSLR for the high impact shots. You can get a TM700 kit, one 7D or two t2i's, and a bunch of glass for less than a single 300/305.

[Glen Vandermolen]

You mean this test?

YouTube - canon422-305.mov

The XF300 is made for broadcast video. It's on another level above the TM700. I know DSLRs have made broadcast images, but I don't consider them broadcast level cameras. Yeah, I know what the BBC said recently about the 5D. Still, they do make beautiful images.
If you don't do much broadcast work, then the aforementioned cameras should do a good job, for cheaper costs.

[Nigel Barker]

Originally Posted by Peter Manojlovic

But the XF300 is a 1920x1080 full raster CMOS censor, with 4:2:2 colour sampling.
My XHA1 outputs 25mbps to tape, whereas the XF300 outputs 50mbps to card...You must realize, there's twice as much data being written.

The XHA1 sensors are also standard HDV resolution i.e. 1440x1080.

[Steve Phillipps]

The bottom line is that it's not that CMOS sensors are inherently better than CCD sensors but that it's easier and therefore cheaper to make them to a certain spec than CCDs. Partly this is due to CMOS needing less cooling and therefore smaller fans, lighter cameras, less power drain.

This is why the PMW500 with CCDs costs about double the price of the PMW350 with CMOS even though both have 2/3" 1920x1080 chips.
Steve

[Peter Moretti]

Originally Posted by Roger Shealy

I think its also fair to say that the XHA1 is encoding to a much less efficient codec (.m2t) and the actual data storage of the 300/305 is probably more like 4 times more dense. ...

I thought HDV and Canon's new MXF wrapped codec both use MPEG-2 compression.

And while the increase from 1440 4:2:0 to 1920 4:2:2 makes a nicer image, it's probably not "efficient" when comparing the amount of storage needed to the increase in image quality. The same goes for moving from 25 mbps to 50 mbps. There is a diminishing rate of returns when increasing codec raster size, chroma resolution, bit depth and data rate.

[Roger Shealy]

Originally Posted by Glen Vandermolen

You mean this test?

YouTube - canon422-305.mov

The XF300 is made for broadcast video. It's on another level above the TM700. I know DSLRs have made broadcast images, but I don't consider them broadcast level cameras. Yeah, I know what the BBC said recently about the 5D. Still, they do make beautiful images.
If you don't do much broadcast work, then the aforementioned cameras should do a good job, for cheaper costs.

That'd be the one. I agree with your comments on broadcast; I was referring to creative work (i.e. cinematic look).

Originally Posted by Peter Moretti

I thought HDV and Canon's new MXF wrapped codec both use MPEG-2 compression.

And while the increase from 1440 4:2:0 to 1920 4:2:2 makes a nicer image, it's probably not "efficient" when comparing the amount of storage needed to the increase in image quality. The same goes for moving from 25 mbps to 50 mbps. There is a diminishing rate of returns when increasing codec raster size, chroma resolution, bit depth and data rate.

I may have spoken out of turn on the codec. I thought the were using an AVC variant, looks like I'm wrong. If it is MPEG-2, it may not be a big efficiency gain.

[Doug Jensen]

Originally Posted by Peter Manojlovic

And yes, there are people who claim that Canon should've gone with bigger censors, but the rep from Canon says that if you go above 1/3 size, then you run into issues of rolling shutter..

Doesn't that sound exactly like something you'd expect a Canon camcorder salesman to say? Do you honestly believe he would not rather be selling a 1/2" camcorder like the EX1R and EX3? I can assure you that those Sony cameras do not have any rolling shutter issues that are worse than the XF305 has. His argument is bogus.

And how does he explain the success of the 5D and 7D? If 1/3" is the sweet spot for CMOS, how can a camera with an image sensor 25x bigger (not sure of the exact number) than a 1/3" sensor be any good?

There's enough good things about the XF305 to talk about without trying to give customers a bunch of BS.

[Chris Hurd]

Originally Posted by Doug Jensen

And how does he explain the success of the 5D and 7D? If 1/3" is the sweet spot for CMOS, how can a camera with an image sensor 25x bigger (not sure of the exact number) than a 1/3" sensor be any good?

Because the 5D and 7D are first and foremost still photo cameras -- always have been, always will be. Video recording is not their primary feature, and yes there are rolling shutter issues with them. It should be clear that Peter's rep was referring to camcorders. A D-SLR with Live View isn't a camcorder. It's a still camera that shoots video, and there is a difference.

[Doug Jensen]

Chris,

I completely understand what you're saying and I do understand the difference between a DSLR that shoots video and a real comcorder. But nevertheless, my point is that the argument that you can't make a decent CMOS chip bigger than 1/3" for use in a camcorder is laughable and easily proven wrong. All you have to is shoot with EX1R, EX3, (1/2") or the PMW-350 (2/3") chips to see that is a silly argument for the Canon rep to try and make. Those Sony cameras do not suffer from any rolling shutter issues that aren't also present in the XF305/300. If I'm not mistaken, I also believe the RED ONE is CMOS.

[Glen Vandermolen]

Yeah, that's a bizarre reason from Canon for using a 1/3" CMOS chip. I think the real reason is obvious - it's cheaper to make a smaller chip for the price point they're aiming for. You trade off the chip size for the broadcast quality codec. Sounds good to me, the end user just has to decide which is more important to their needs.
I think the XF300's only real competition - price wise - is the EX1R. So, do you want the larger chips in the EX or the better codec in the XF? Apparently both give outstanding images.

[Roger Shealy]

Isn't the reason Canon uses a smaller chip is to offer a great lens with wide zoom at a low cost? My understanding is that as the sensor gets bigger, the cost & size of the lens goes up disproportionately as you try to offer IQ over a wide zoom range.

[Glen Vandermolen]

Originally Posted by Roger Shealy

Isn't the reason Canon uses a smaller chip is to offer a great lens with wide zoom at a low cost? My understanding is that as the sensor gets bigger, the cost & size of the lens goes up disproportionately as you try to offer IQ over a wide zoom range.

Yup, that too. It makes sense, as this camera is also aimed toward the budget-conscious TV news organisations (as most of them are now). They want the longer zoom capability. 1/3" chips are just fine. Even if you have to go very high gain to get a noisy night shot, it's all good. For TV news, getting the money shot is more important than how it looks aesthetically.

[Doug Jensen]

Glen and Roger,
I think that you are both right about the reason for the 1/3" sensors.

But I disagree with Glen about the only competition for the XF305/XF300 being the EX1R. Don't forget about the EX3. For my money, the EX3 is still the best bang for the buck out there if you can live with the slighly larger size. The superior viewfinder, removable lens, etc. are important considerations that shouldn't be overlooked.

But as I have posted before, all four cameras are excellent. You won't be making a mistake with any of them. Pick one, learn to use it, and start making money with it. Unless you're a hobbyist, these are just business tools that allow us to work faster, better, and more efficiently. Let's not lose sight of that!

You're never going to find everything you want in a single camera, anymore than you could find the perfect car, perfect house, or perfect spouse. You give up some things in order to get other things that are more important to YOU.