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-   JVC GR-HD1U / JY-HD10U (https://www.dvinfo.net/forum/jvc-gr-hd1u-jy-hd10u/)
-   -   JY-HD10u vs DVX-100 report (https://www.dvinfo.net/forum/jvc-gr-hd1u-jy-hd10u/14379-jy-hd10u-vs-dvx-100-report.html)

Eric Bilodeau September 16th, 2003 02:37 PM

Yes, the 4:2:0 is a bit tricky, but I doubt it is the case since compression seems to be equally visible on the blue and red channels, this should not be the case on a 4:2:0 since the blue would be much more artefacted and the red a lot less. I still think it is closer to 4:1:1, maybe not exactly but close.

As for the comparison with miniDVs, you indeed have to test it to see that advantages seem to be on JVC's side for the image but certainly not for the ease of use and pro features. I personnaly will shoot HDV for my next productions, definition is important to me and quality is surprisingly good. I simply cannot go back to DV now that I have seen HDV even for SD production.

Ken Hodson September 16th, 2003 03:08 PM

Here is a good link on the subject. It seems that 4:2:0 is very common for mpeg2.

http://www.dv.com/columns/columns_item.jhtml;jsessionid=YFA20VZZYTXQ0QSNDBCSKHY?category=Technical+Difficulties&LookupId=/xml/feature/2003/wilt0603

I am a little confussed by all this. As I understand the second and third values are lumanice and chroma not blue and red. Can you help clarify?
Also I am really interested in this cams abillity to do blue-screen. What does all this mean in regards to this cam performing this function?

Eric Bilodeau September 16th, 2003 03:44 PM

Take a look at this article: http://203.94.147.64/supportView.asp?view=3 witch explains the numerology of compression. But I just read about the 4:2:0 on another article. 4:2:0 is not as the other a Y:Cr:Cb reference, it is a intuitive notation on witch the chroma is half-luma spread in both the horizontal and vertical dimensions. It is the pal equivalent of 4:1:1 because of PAL's better horizontal resolution than DV. it seems that this sampling is more subject to degradation by multiple generations than the 4:1:1 sampling. DVDs use this sample as well. So I suppose this means that the JVC indeed is 4:2:0...

It is supposed to be better in progressive than in interlaced, guess that is why they chose it for HDV. It really looks equivalent to 4:1:1 DV head to head.

Eric Bilodeau September 16th, 2003 03:47 PM

As for blue screening, I did do green screening tests on the JVC and it looks very good. Definition of couse is a major gain over DV. Artefacting looks less problematic than in DV but still is present. I suspect Blue screening to be equally efficient. But there are still many tests to be done on that field.

Eric Bilodeau September 16th, 2003 03:51 PM

Ken, If I remember correctly you asked me about green screen the last time am I right? If so I think you will find the JVC interresting on that point, I have not tested deartefacting with Magic Bullet but I will.

Darren Kelly September 16th, 2003 03:53 PM

I and another fellow will be testing the keying for this camera very soon.

I'll report back.

Cheers

DBK

Ken Hodson September 16th, 2003 05:46 PM

Thanks guys. I look forward to it.
I am interested to finding out if the lack of manual controlls durning shooting, translates to removal problems in post. Also do you find a particular screen colour works best for keying with this cam?
ken

Darren Kelly September 16th, 2003 05:50 PM

Welol, We'll try and do both!

DBK

Betsy Moore September 16th, 2003 05:59 PM

Re: color saturation. All I know is I shot footage in my 1920s era bathroom of blue-green tile, orange rug, multi-colored towels using only the light coming in from the medium-sized window and from what I saw the colors popped out like an MGM musical from the 50s. It's no VHS for the new millennium. You can talk bit rates all you want but the proof is in the pudding.

Eric Bilodeau September 16th, 2003 07:01 PM

A rather elegant way to make your point Betsy. This indeed is no VHS, it is a 21st century toy indeed. And colors look good, real good under a decent light. My images (EBil_V1.m2t and EBil_V3.m2t available at [url]http://static.dvinfo.net/ericb/[/url) are a good proof of how interresting reddish colors can look in this camera despite the compression and all. They where taken without any added light other than the sun and it looks very good. Another shot from Mike Eby (with the HD1) show a very beautiful and quite colorful flower at this adress: http://www.advancedcomputerdesigns.com/hd1demo.m2t. If you can post a clip, I'd like to see that 1920s era bathroom of yours from the Beast's eye.

Brian Mitchell Warshawsky January 13th, 2004 10:09 AM

"Pure"
 
Eric,

I didn't see where you made the final decision. Was this the HD10U over the DVX100?

Thanks,

Brian

Eric Bilodeau January 13th, 2004 10:12 AM

They had a deal over the Varicam so they used it. But they would have chosen the HD10 over the DVX mostly because of definition. The feature has already been shot and is in post production.

Graeme Nattress January 13th, 2004 11:30 AM

I personally find 4:1:1 easier to work with than 4:2:0 because it's easier to upsample the 4:1:1 to something better, whereas it's pretty hard to get 4:2:0 look nicer than what it starts at (it can be improved a bit, but not too much). However, both are recording the same amount of information - 1 chroma sample per 4 luminance samples, but think of it as 4:1:1 has the 4 luminance samples in a row, and 4:2:0 has the 4 luminance samples in a square.

Graeme

Eric Bilodeau January 13th, 2004 11:40 AM

agreed, but then 4:2:0 is more problematic in interlace than progressive.
I am sure good progressive 4:2:0 filters could be done.

Diu Hai January 14th, 2004 12:49 AM

the OP said "The fourth issue is night shots. Or if you prefer shots with objects exposed to light while others are not. Here the JVC impressively outperforms the DVX (or any miniDV I have seen so far)."

what mode does the DVX run? a huge difference if the dvx runs in progressive mode(no gain). if the dvx run in 60i, it simply blows hd10 away, and any other cheapo DV i have beat the hd10 in low light. even my trv 27 has a better low light than the hd10(in DV mode, auto).
i know it because i have both dvx100 and hd10.


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