Any reviews with hard facts?

[Toke Lahti]

Fx1 has been in stores for more than a month now and demo pieces of z1 are travelling around the globe.
Is there still any review published about these cams, that would have been done with scientific methods in lab environment by professional people?
Just the basic things like resolution, latitude, lens distortions with diffrent aperture, shutter speeds and cf-modes.

Comparison with other cams would be useful as well as with uncompressed (analog component hd's bitdepth?) and compressed output (tape & fw).

Especially resolution with slow shutter & cf interests me, because I was speculating before, that these ccd's might be progressive after all and if they are then Reel Stream's 14/12bit 4:4:4 -hack would sound amazingly interesting.

Still about the ccd's, this is what Steve Mullen says about them:
"How difficult would it be for the Pro version of the FX1 to support 24p video? Perhaps not difficult at all — if the CCDs' frame rate can be set to 24fps instead of 30fps. CCDs are inherently progressive; thus, every CCD readout yields 1080 lines. For interlaced scanning, “row pair summation” creates a 540-line field from each scan. However, were summation disabled and every other readout discarded, each 1/24 of a second, all 1080 lines from the CCDs would become a progressive frame stored in a buffer. From the buffer, alternating “fields” of 540 odd and 540 even lines would become available as needed. (The fields, of course, are not interlaced.) This mode of operation is very similar to the 1080/PsF24 recording used by Sony CineAlta cameras."

[Bill Pryor]

What I'd like to see is a test that shows a comparison of the DV mode of the camera, the HDV mode, and the same thing that was shot in the HDV mode and then transferred to DV via firewire.

[Heath McKnight]

I can do that soon, DV and HDV.

heath

[Bill Pryor]

That would be cool. What I'm really interested in is what the video would look like if you shoot something HDV, then transfer it to DV, as compared to shooting the same thing DV. Just curious if there is a difference and what it would be...wondering if the higher res of HDV would make a downres image look any different, better or worse, than originally shooting in the DV mode.

[Chris Hurd]

Anything that Heath comes up with, we'll run his reports here in a big way.

[Bill Pryor]

Excellent. This is probably a dumb thought, but I was thinking about how we shoot 16mm and then have it transferred to Digibeta, usually, and then to DVCAM for editing, and that looks better than anything shot original DVCAM; just as HD downrezzed to DVCAM looks better. So I was wondering if the higher res of HDV, when transferred down to DV/DVCAM, might perhaps look better than the same shot originated by the same camera in DV/DVCAM.

[John Jay]

I have a clip of Kaku downrezzed to 30P mpeg NTSC DVD which looks stunning. If Chris can host I can up (~50meg)

[Steven Gotz]

I was thinking of doing that exact thing. Shoot HDV, change tapes, shoot DV, and then use the old Canon ZR10 to shoot the same thing. I am taking the little camborder along as a rewinder / tape retensoner, anyway.

I could post stills of the results I suppose. Although I can't imagine any real difference between HDV exported as DV, and shooting DV to export as DV. It would be interesting though. What if DV exported as DV looked better than HDV exported as DV? What would that do to our workflow?

[Barry Green]

I've been running all sorts of tests on FX1 vs DVX vs XL2, and most recently we've been focusing on the aspect of "how does it look on DVD"?

On a high-def TV, obviously there's no contest, the FX1 is high-def. But for the next several years, content is going to still be distributed on DVD, so how does the FX1 compare to straight DV cameras when producing content for release on DVD?

There's a huge thread running on another forum with all the results so far, but I don't necessarily want to point anyone out of the dvinfo.net family. If I could post images in-line in a thread here I'd do so, but there are so many pictures that it would be awkward to constantly refer someone out of the thread to a picture and then back.

In quick summation, my conclusion is that for DVD release, the DVX and XL2 produce a superior picture on DVD than downrezzed FX1 does, whether the FX1 is downrezzed in-camera (outputting DV from the firewire port) or downrezzed in post (using Vegas 5.0, "Best" video quality for bicubic resizing, outputting from the straight camera original .m2t transport stream). It's not a night-and-day difference, and other than the sensitivity issue it could be argued that all three cameras are producing basically the same resolution, with the FX1 delivering a slightly, tiny bit softer image at DVD resolution, but certainly all are within spitting distance of each other. Where the FX1 takes a step back, for SD DVD production, is that it doesn't offer all the other features of the XL2 and DVX, such as 24P or 30P, XLR audio, and it's the least-light-sensitive of the group.

The FX1 makes great high-def images, that's for sure. But if you're looking to improve the video quality of your DVD's, the FX1 will not help you, as compared to the DVX and XL2.

[David Newman]

Barry, technically I believe the opposite is true. If we ignore lens and sensetivity characters and use the common mode 30p for comparison; the best SD source and best HD source downscaled to SD will have equal luma resolution 720x480. Note: HD's oversampling can have an edge in luma, yet good SD cameras oversample these days anyway (e.g. XL2), so they're equal. Chroma is a different matter, DV NTSC has a maximum chroma res of 180x480, whereas the FX1 has a maximum chroma res of 720x540. Given that DVDs are 4:2:0 with a maximum chroma resolution of 360x240, only the HDV source can achieve the full chroma resolution of a DVD. DV converted to DVD gives you a maximum chroma resolution of only 180x240. For this reason I would not recommend using the HDV->DV path, as result are better when editing HD then doing a down res to DVD on output.

[Davi Dortas]

Or you is edit in DV50 mode like with DVCPRO 50 codec from Apple. It will scale down FX1 footage to 4:2:2, good enough for real-time editing and final distributing on DVD, without need to edit in HDV. Of course, edit in HDV if you thinks you will need a HD master later on.


FOr this very reason, I think it is prudent to use FX1 as it is better than any SD DV camera for the color resolutions alone.

[Davi Dortas]

Is chroma res of NTSC DV, 180x480? It is 180x480 I think. Remember only 1 chroma sample for every 4 luma samples, so if luma is 720, divide by 4 and you is getting you correct number of 180x480. Very same indeed.

Like in my last posting, if you downrezz FX1 footage to 100% photoJpeg or MJPEG, you WILL GET 4:4:4 CHROMA!!! For this reasons alone, the FX1 is MUCH BETTER than XL2 or DVX100. Then also the PAL version can shoot 50i, convert it to 24P NTSC and it blows away DVX100 footage. I can guarantees that much.

[Toke Lahti]

Has anybody ever showed anykind of resolution chart to these hdv cameras?
Another thing that interests me is chromatic aberration.
With my fast hands on test aperture full open and max tele, I saw quite lot of it.
So comparison eg with xl2's "not hd" lense would be very nice...

[David Newman]

<<<-- Originally posted by Davi Dortas : Is not chroma res of NTSC DV, 180x120? It is not 180x480 I dont think. Remember only 1 chroma sample for every 4 luma samples, so if luma is 720x480, divide by 4 and you is getting my correct number of 180x120. Very bad indeed.-->>>

You have you math a little wrong, that would end up with one chroma for every 16 luma. :) 4:1:1 subsamples luma horizontally only. Chroma res for NTSC DV is 180x480.

[Barry Green]

David Newman : Barry, technically I believe the opposite is true. -- Given that DVDs are 4:2:0 with a maximum chroma resolution of 360x240, only the HDV source can achieve the full chroma resolution of a DVD. DV converted to DVD gives you a maximum chroma resolution of only 180x240.

David, I know what you're saying, and theoretically it sounds good. But in practice, it's not happening. The XL2 and the DVX just plain look better, on DVD, than the FX1 does.

I'm taking footage shot side-by-side, same identical frames in time, from each camera, and split-screening it and making a DVD of it. I'm using the FX1 original HDV source, rather than using a DV proxy of it, specifically for what you said. If you convert FX1 to DV first, you'll force it through a downrez and a color space conversion, and then when it goes to DVD it'll go through another compression cycle and another color space conversion.

The way I'm doing it, it goes through one downrez and no color space conversions.

But the end result is, the DVX and XL2 footage looks slightly sharper and more detailed with better color. The downrezzed FX1 footage is close, yes, but it's not in any observable way "better".

For this reason I would not recommend using the HDV->DV path, as result are better when editing HD then doing a down res to DVD on output.

I agree, and that's the way I've been doing it.