HV20 HDMI vs HDV picture quality
 

Sine the only true way to get 1920x1080 and then 24Progressive is through HDMI since HDV no matter what, it is 1440x1080 60i. did someone try to compare a captured m2t played back on TV and directly from Camera through HDMI to see if there are real noticable difference or is it almost the same?

I just wonder if we lose a lot because of HDV downgrade

I second that question! Of course, theoretically HDMI should have more horizontal luma resolution, more chroma resolution, no compression artifacts (?) but has anyone actually put this to the test? And--while we're at it, some samples anyone? ;)

I think this is contingent on Blackmagic's Intensity HDMI input card working with the HV20. At the moment it doesn't

Bruce Allen
www.boacinema.com

Bruce, any clue as to why not? Are all flavors of HDMI not the same?

I can't be specific but as i understand it there's just some kindof issue that stops it recording full resolution. There is a thread that has a bit more info but i can't remember the tittle at this moment. But worth looking for guys.

Yes. I was on that thread too. I am pretty sure that the signal chain is:
capture at 1920x1080 -> do white balance, processing, etc -> 1440x1080 -> scale back up to 1920x1080 for HDMI output.

So, you wouldn't get true 1920 resolution. Not that that's much of an issue.

I offered to send beers or chocolates to the first person to post comparison HDMI vs HDV tests.

Bruce Allen
www.boacinema.com

What you describe here i believe is just coming off an already recoded tape. The question still remains about live capture.

I recently compared HDMI and HDV captured scenes. There is not much difference visible in static scenes, except the slightly increased vertical color resolution (422 instead of 420).

See http://www.dvinfo.net/conf/showpost....4&postcount=15

Heinz Bihlmeir

Thanks! Heinz, send me your address and beer / chocolate choice!

Although you're in Germany so I'm sure you have access to much better stuff than me here in LA...

You used a HDMI -> HD-SDI converter and then captured from the HD-SDI, right?

Bruce Allen
www.boacinema.com

Actually, Heinz, would mind posting some actual frames please? You posted some kind of cool waveform monitor graph thing but I couldn't find the real frames.

Thanks

Bruce

Yeah, if you could post actual HDMI / HDV frames (preferably very colorful scenes so that 4:2:0 / 4:2:2 diference is noticable.

Or heck, maybe a green screen grab ;)

I didn't think there would be with static shots...only slightly.

I'm sure though there would be a great deal of difference with motion in the video as opposed to the HDV compression.

Thanks, but I don't need any beer. With the "Hofbräuhaus" only a half mile away here in Munich, I think we have enough supply.

Yes, I use a HDMI to SDI converter.

I have uploaded frame captures (psd format) from a still scene and a pan sequence (car in motion). Images are captured from the HDMI port to compare realtime and tape playback (HDV) quality. The supplied vector diagram shows that the vertical color resolution is reduced in the HDV capture.

Link: http://rapidshare.com/files/29630650/HV20HDMI.zip.html

Heinz Bihlmeir

I tested a bit in photoshop with your stills, and the only difference would be when you do some heavy color correction you see minimal jpg like artifacts in the hdv version

I don't think most folks will see the difference of non comressed HDMI VS compressed Tape output... its just not a lot of difference...

There will be the discussion that you wont see compression artifacts and that argument is true.. but for most of us, it just does not matter that much.

but if your using a real time capture device like the black magic board then you have the capability to use a reference display, a monitor or projector,
that will allow you to view the footage on the display, non compressed, and be able to dial in your shot... adjust your settings, adjust your lighting, adjust your angles.. and so forth...
not just based on the cam' small display...
your not going to see zebra on a non compressed HDMI capture... you better be hooked up to the monitor display and using it as the gospel... cause thats all your going to get... so use it, thats what its for :-)

Then when you hit the record button you know exactly what you are capturing, real time... no farting around about did I get that shot the way I wanted it or do I need to shoot it over and over again with different settings.

you look at the reference display and you dial in the shot and when its what you want you hit the record button....