John,
Sounds like your Z1 experiences are similar to mine, and to many others here regarding gain. Maybe if you had an ND filter on in a bright room, you'd need gain, but the cam will let you know you've got it on.
You can get to about +12 with the Z1 without experiencing horrid noise, and if you turn sharpening down to around 8, you can get even more clean image, and additionally, adding black stretch if you've got a bright light in there somewhere, will clean it up even more. The demo footage that was shot at the Bellagio was simply over the top, going from straight and slightly noisy black with zero lighting to managing the extreme bright whites of the lights and fountains, while still giving a great set of red and blue images, and showing detail on the hotel marquee (unlit) itself.

Michael, to comment on your question re: tape...BASF had a demo of HDV tape at their booth, and clearly demonstrated a better image due to higher grade tape. Why? Because there is a better signal to noise ratio in the higher grades (+4 in the Sony tape, which is likely made by BASF) and higher signal to noise, coupled with HDV's better error correction, means the decoder is doing less work. I never would have believed it, had I not seen the diff. I'm pretty sure the way they'd set up their demo was doing a firewire to firewire transfer. I'd imagine that the JVC would enjoy the same benefits of better grade tape. It might be interesting to compare Charles/Nate/Barry's taped footage with the DVRack HD looking at scopes or on an HD/SDI monitor to see if there are any differences.

" and higher signal to noise, coupled with HDV's better error correction, means the decoder is doing less work. I never would have believed it, had I not seen the diff."

I would like to see that to believe it, from what I gather the better tape has better "Carrier" signal to noise ratio, not better signal to noise ratio like one would think in term of camera head, or analog recording, did they advertised better picture quality for real?

It's a better carrier signal, advertised/marketed as S/N ratio.
Sony wasn't claiming anything with the tape at NAB, but BASF was showing both cheap tape and high grade tape, and you could definitely see a difference. Nothing that you could place a finger on, just a difference.
My initial impression was that it was snake oil, similar to Monster or other high end cables. But you could indeed see a difference. Why? I don't know. After all, it is just 1's and 0's. If it's readable at all, it's identical to what the cam put there.

sony's claims run to error reduction of 90%, better carrier (which they term signal to noise) by +4dB, 50% fewer dropouts, and dual layers of magnetic material. The only other claim I've seen/heard Sony make is that because it's 16:9 vs 4:3, the additional information increases the margin for error to tape. Therefore, the new tape formula reduces risk by a substantial amount.

But there's a difference between cheap DV tape vs HDV tape and good DV tape vs HDV tape IMO.

DVX's go for about $200 here in Los Angeles, so I've heard rumblings of $325-350 for the HD100.

I know I've seen the DVX go for much less than that in smaller markets, though.

Better tape, better technology? The analogue days are over. It is all marketing.

Any idea why I know this for certain? I'm a master in physics, and my field of expertise is image compression....

Better tape yields fewer dropouts. which means, fewer artefacts. Richer colours? finer detail? All-round better image quality? Nonsense.

Especially with the MPEG2. One could imagine that there would be very, very tine drop-outs, just altering a few pixels, and therefor lesser video-quality, but since it is MPEG2, the video is either right (no artefact), or either wrong (seriously visible artefact). Due to the digital concept and the MPEG2 compression, there's nothing inbetween.

Better tape yields lower noise in the Image? Nonsense....
Better colour-reproduction? Nonsense...
Finer focus? Nonsense...

I would go for the better tape, but for the right reasons: lower possibility on a drop-out...

Exactly. In Analog it made a difference, in digital it *cannot* make a difference, other than dropout performance.

Werner,

Thanks for putting a cork in the S/N theories.

I guess we don't "NEED to Know" the differences between analog and digital.

No problem - any time... :-)

All of the 3CCD DV camcorders tend to require +6dB to +9dB in about 500W of light, so given that we KNOW the the Z1 is several stops less sensitive, +12dB to +18dB seemed just about what I would expect.

Thankfully, the noise was not too bad. But, the camera clearly is not great in low-light -- as every review has noted.

And, that's what I found.

...which is in line with the general difference between SD and HD. Correct me if I am wrong but I seem to remember that even CineAlta is slower than say DigiBeta or the BVW400/600 line of cameras. Nature of bigger chips...

It's not the nature of bigger chips, it's the nature of smaller pixels. The CineAlta's chips are about the same size as the BVW600's, but they have something like 4x as many pixels on them. Those pixels are, therefore, about 1/4 the size of the pixels on the 600.

The smaller the pixels, the less light sensitivity.

All HD cameras are going to be less sensitive (i.e., slower) than a comparable-CCD, comparable-technology SD camera, because the SD camera is going to have much bigger pixels. All these 1/3" CCD HD/HDV cameras are going to be slower than their SD counterparts.

Thanks Barry, that's what I meant. Bigger as in more dense...thanks for the clarification.

It's just the amount of photons that can reach te CCD's.... if you lower the framerate, the CCDs are more sensitive as well (slower shutter tto - of course...)

Again with all due respect, Steve, I do not agree with any of those figures. What 3CCD cams? How are you determining exposure?