I dont get it... Effective pixels

[Agus Casse]

Hello, i have been watching a lot of specs of several cameras, and i found that the DVX100 have 380,000 effective pixels... now i watch some specs and i found that the TRV70 from sony have 1,000,000 effective aprox..

so, which camera has more resolution, or better video quality ?

leaving besides the 24p, audio quality, and just resolution and picture quality.

Thanks for all.

[Stephen van Vuuren]

Note that Panasonic has 3 CCDs while the TRV70 has 1 CCD.

Plus, CCD's come in different sizes. The TRV70's CCD is smaller than that of a VX2000. The Panasonic DVX100 also has 3, 1/3" CCDs---much better low light plus a seperate CCD for red, green and blue (than the TRV70).

3 CCD cams usually capture better/richer footage, except for stills.

[Agus Casse]

So what does all those numbers means, if one is 1mb effective, and another one is 380K effective, but still the 380k is better... well... i still dont get it, i do understand what you said, but still dont get how does it work, or how to choose between cameras..

[Chris Hurd]

Total number is the pixel count of the entire array on a CCD. Effective number is the amount actually used to generate the image. Basically there's a border of unused pixels all the way around the edges. That's the way it works, and it's pretty common to list both the total and effective pixel counts.

Three CCD's at 380,000 effective pixels each are generally considered better than a single CCD at 1 million pixels total. Unless that single chip has a primary color filter, but that's a whole other deal there.

Keep in mind that all CCD's are monochromatic, analog devices. They have to be told what "color" is, through overlay filters or prisms, and they need analog-to-digital converters (called A/D converters) in order to make digital video. Hope this helps,

[Agus Casse]

Very interesting.. want more info .. mooore !!! ehhehehe

so let see.. even if 3CCDS are 380K they are better than 1M single CDD...

Does CDD improves DOF ?? i read that somewhere... dont sure...

what is that about advanced HAD CDD ? (Imaging Device: 1/3.6", 2110K Gross Pixels, Advanced HAD™ CCD) in the TRV70 ... i tried it today, but still it doesnt perform well at low light.. it has good DOF, but picture quality is not as good...

[Frank Granovski]

so let see.. even if 3CCDS are 380K they are better than 1M single CDD.

Better how?

Does CDD improves DOF

No. But a larger CCD gives you the option of getting a smaller DOF when the iris open.

HAD...but still it doesnt perform well at low light.. it has good DOF, but picture quality is not as good...

Don't get "HAD." You get what you pay for...most of the time. :)

[Barry Green]

Consumer cameras with built-in digital still cameras frequently have high pixel counts (i.e., 1 million pixels, or more).

Professional video cameras don't bother with including digital still cameras, they're only concerned with providing ultimate video quality, and professional cameras never bother with megapixel CCD's: they have just enough pixels to cover the frame.

In general, having a high-pixel-count CCD will harm video quality, by reducing low-light performance. Megapixel cameras usually have worse low-light performance.

The one exception is the new technology being employed in Panasonic and Sony cameras, to use the megapixel CCD in such a way as to provide high-quality 16x9 footage. For extracting high-quality 16x9, having a high-pixel-count CCD comes in handy, and for digital still photos a high-pixel-count CCD is good. But for regular video, the megapixel CCD's generally do more harm than good.

[Agus Casse]

I actually have a TRV18... and i tested versus a TRV70, actually the old TRV18 model beat the shit out of the TRV70 in low light, but i dont have as good DOF as the 70...


I just cant wait to make some money and buy the DVX100, do you think it will lower up its price ?

btw (using the TRV18 with color correction, and magic bullet, gives me some nice results, of course, for tv propurses, not film)...

ok. thanks for all the tips, you cleared my head a lot.. thanks people...

[Bryan Mitchell]

<<<-- Originally posted by Barry Green : Professional video cameras don't bother with including digital still cameras, they're only concerned with providing ultimate video quality -->>>

My XL1s bothers with still shots :-p but you're probably just saying that a video camera Shouldn't focus on still photos, right?

[Yik Kuen]

Hi,

If I'm on the right track on what you guys are discussing, guess which cams has the most pixels ?

Yes, the 950 and PDX-10. They have 1Million x 3 !

[Cooleye Hu]

Don't be misleading here, 1M CCD can definetly capture more details than 380K. The reason why the VX2000 is still better than TRV70 is because the current TV only support 530 horizontal scan line, and the 3CCD 380K VX2000 can provide enough detail for the maximum TV capacity. If you are using HDTV then the difference might be seen. Another thing be noticed is that no matter how high the effective CCD is , the DV format is always 720X480, so, you can see 38K is ok for that format. Although TRV70 can use 1M CCD for video capture, finally it has to be resized to 720X480. However theoretically the 1M CCD should provide better detail on good light conditions. BUt VX2000 are so good in their optics, color reproduction and other controls, that is why you see the VX2000 is better than TRV70, NOTE: the picture quality is not ONLY determined by the effective CCD, especially when the effective size is >380K and you are watching on normal TV:)

[Yik Kuen]

Hi Cooleye,

I did a side-by-side comparison at home last Saturday, the PD-150E and DCR-PC110E.

Guess what, it's quite difficult to tell which is which! Both the Sony cams deliver good images with roughly the same colormetri when we viewed them on a tv.

However, under low-light, PC110E is no match for the PD-150.

Our conclusion : The new breed of 1M-1CCD consumer cams can deliver good quality output that rival 3CCDs provided they are fed with enough lights. The only valid reasons left for buying a prosumer cam are better low-light and more manual controls.

[Agus Casse]

I tried my old TRV18 vs a TRV70 and the TRV18 films better at low light than the new one.. but TRV70 have better DOF...

[Barry Green]

Megapixel CCD's hurt low-light performance. That's why you're finding better low-light performance on the older models.

[Juan P. Pertierra]

It's all a tradeoff, Agus...

The way Sony single chip cameras capture color, is by using mosaic filters...that is, in front of each CCD 'pixel' sensor, there is either a Cyan, Magenta, Yellow or Green filter. Of course, the output image looks like a mosaic but the color for every pixel can then be ~approximated~ using a combination of the values from adjacent pixels.

Naturally, the larger the CCD and the more the resolution, the better the color approximation...but it will never ~theoretically~ reach the accurate color depiction of a 3CCD system, even though some single chip cameras with high pixel counts have pretty good color. The question you should ask yourself is, is it a good enough approximation for your application?

That said, and DV compression excluded(we're talking raw image from the CCD's here), a 1Megapixel CCD WILL capture more resolution detail than a 3CCD 380k system. The issue here is, that 3CCD systems are usually professional systems, and since you're aiming for television(ENG, whatever), the main issue is accurate (>near< broadcast standard)color representation. Not to mention, that looking at similarly priced camcorders, a 3CCD system will probably have smaller CCD's than a single-chipper of the same price for obvious reasons.

Note also, that 'detail' is kind of subjective. Above I used detail as in raw resolution...as in comparing two monochrome CCD's of different resolutions to each other...or comparing line-resolution. However, color representation also adds to the 'detail' that we subjectively see. Try comparing two pictures in your computer at the same resolution but at 4-bit color and 32-bit color and you'll see what I mean.
Even a 320x240 image will look amazingly good given millions of colors to work with.

And then you also have the issue of low-light sensitivity..the more dense the CCD(i.e.pixels/unit of area) usually the worse the low-light performance, because the individual pixel elements have less area to receive incoming photons.

Hope this helps.
Juan