Panasonic DVX100A vs. SDX900

May 11, 2005

Hello,

I am a production manager for a film/video production house. We own our own DVX100A but for higher-end work we often shoot on the SDX900. We have a job in house now that falls right in between the cost of these two cameras - so what I'm trying to find out is how the resolutions of these cameras compare to each other in their various shooting modes. Let me state further that I'm somewhat of a novice when it comes to cameras and lenses - so please bear with me.

1) I know the DVX100A has 410,000 pixels, and the 900 520,000. Does this mean that, at base, the 900 has approximately 25% more resolution?

But: 1a) The DVX100A has a 1/3" chip; the SDX900 a 2/3" chip. Would that mean the SDX is twice as good?

2) How much resolution does the DVX100A have in Letterbox mode? In Squeeze mode? With the anamorphic adaptor?

3) How much resolution does the SDX900 have in 16x9 mode? In 4x3 mode?

4) Is 'pixels' the appropriate way to measure resolution? Or should I be measuring the vertical vs. horizontal lines?

Any help that anyone could offer would be greatly appreciated; all Panasonic seems to be able to tell me is that the SDX900 offers a better image - which I already knew. Essentially I need to be able to tell my director how much better that image is in a mathematical sense.

I thank you in advance!!

--Matt

Gordon Highland · May 11, 2005

I'm not good with the math of it, but most of it is in the chip and the glass. SDX has an actual 16:9 chip, so there's a huge difference there if that's how you want to shoot (the 4:3 mode takes a cut out of the middle of the chip). The lenses and lens options are going to be greatly enhanced with the SDX. If you shoot in DV50 mode on the SDX, it is literally twice the bandwidth (and nearly half the compression of DV). It is only 3:1 instead of 5:1, and it samples the color at twice the resolution (same brightness), which translates to much better chromakeys if that is part of your production. Many would say that regular DV (DVX100) is not acceptable for professional compositing and chromakeys. Of course, you'll need a separate deck to play back/import DV50 tapes from the SDX, and that's a cost consideration. I believe the wide angle on the DVX may allow you to shoot in tighter quarters, and it's much more inconspicuous in public if that's an advantage.

Landon D. Parks · May 13, 2005

May I suggest up-grading your camera package to the new Canon XL2? Native 16:9 chip, interchangable lenses, cine-modes, good resolution, good quality... And it looks a bit more professional than the DVX (No offense to DVX users). It has a whole wealth of features, but the biggest advantage is the fact that it has a 16:9 native chip, which i think its the only pro-sumer SD DV camera to have that at this time.

John Ealer · May 13, 2005

1) I know the DVX100A has 410,000 pixels, and the 900 520,000. Does this mean that, at base, the 900 has approximately 25% more resolution?

Yes, at the sensor. Keep in mind that all standard def DV variants record a 720x480 pixel image to tape. DV uses 8-bit 4:1:1 chroma subsampling, which means you have effective chroma resolution around 180x480, which is why chroma keying with DV is tricky. Each frame is M-JPEG compressed at 5:1. In DVCPRO50 with the SDX-900, you have 8-bit 4:2:2 chroma subsampling, which means the effective chroma resolution is 360x480. Each frame is M-JPEG compressed around 3.3:1.

Keep in mind as well that the SDX-900 utilizes 12-bit A/D conversion and the DSP operates in 10-bit uncompressed. Also, the SDX-900 processes 16:9 footage at 960x480 resolution (unsqueezed); the image isn't squeezed down to 720x480 'til it's transcoded and recorded to tape. I don't have the comparable stats for the DVX-100A, except that it does have a 12-bit A/D converter. (The original DVX-100 had a 10-bit A/D)

But: 1a) The DVX100A has a 1/3" chip; the SDX900 a 2/3" chip. Would that mean the SDX is twice as good?

No. It means you have, roughly speaking, half as much depth of field with the 900, which is something I like. It also means the front end of the 900 is bigger, etc.

2) How much resolution does the DVX100A have in Letterbox mode? In Squeeze mode? With the anamorphic adaptor?

3) How much resolution does the SDX900 have in 16x9 mode? In 4x3 mode?

The DVX-100A uses a 4:3 sensor, so whenever you're shooting in 16:9 with that camera (except with the anamorphic adaptor) you're not using 25% of the pixels, i.e. you're only using about 300,000 of the 410,000 sensors on those chips. The SDX-900, with it's 16:9 sensors, has to throw away the sides of the frame to get to 4:3, but even after the crop you still have about the same number of sensor sites as the DVX-100 has.

Hope this helps.

J