DVCPRO50 vs. DV at DVinfo.net

Barry Green · January 31st, 2006, 03:59 AM

Thought you might like to see how much of a difference it makes to shoot in DVCPRO50 mode vs. standard DV mode, on the same HVX.

We were shooting some greenscreen tests, and we shot the exact same subject in the exact same lighting with the exact same camera on the exact same settings; the only thing that changed was I changed the recording format from DV to DVCPRO50 and then had the actress do the same actions.

Here's an uncompressed frame extraction from the familiar DV that we all know (4:1:1 color sampling):
http://www.fiftv.com/HVX200/DV25-Green.png

Here's 4:2:2 DVCPRO50:
http://www.fiftv.com/HVX200/DV50-Green.png

And if you want to see the images blown up, here's an extraction of her right hand at 400% size:
http://www.fiftv.com/HVX200/DV25-vs-DV50.png

Remember, absolutely nothing else changed. These shots were taken within seconds of each other. This is not trying to compare one camera against another; these shots were taken on the same HVX200. The only change whatsoever was to change the recording format from DV to DVCPRO50.

R Geoff Baker · January 31st, 2006, 05:42 AM

Thanks for your posting, but a still life would be more indicative -- I would guess that the right hand is 'flapping' in the 4:1:1 shot and so an awful lot of what we are seeing is motion artifacting/interlace converted to stills problems -- or at least so I would have to assume.

Maybe a nice bowl of fruit with a shiny can of Coca Cola and a spray of delicate flowers against a textured background would help ....

Cheers,
GB

Peter Jefferson · January 31st, 2006, 07:02 AM

" but a still life would be more indicative "

with my experience with DVCpro50, i beg to differ...motion artifacts in DV are pretty appalling, but those same shots with DVCPro50 can look stunning...
even this grab as an example.. look at the jaggies on DV... and colour... well it doesnt need commentary...

A still life, shot for 15seconds would be a better indicator of compression motion artefacts, not just a still shot taken from DV...

Ive always loved DVCpro50... i always thought it was the bees knees but price was abhorent...
Im glad to see the format making headway into "this" market... at least it will be appreciated by those that will be using it the most.. and those that have never used it, will come to appreciate the difference...

from the looks of it, not many ppl have used DV50 which prolly explains the lack of interest so far as everyone is focused on DVCProHD...

Scott Anderson · January 31st, 2006, 07:15 AM

But objects in motion are exactly where keying problems occur. That, and those high-contrast diagonal lines that are the cause of obvious blocking in DV. What an amazing difference!

Having never worked in DVCPro50, I am wondering if the apparent increase in latittude is simply due to the increased color sampling. I noticed in the stills of the lizard sculpture, there was also more saturation and more contrast. It's as if the highlights remain about the same, but the camera digs deeper into the blacks. I would have expected more saturation, but not that much more contrast.

Bob Grant · January 31st, 2006, 07:37 AM

I've never worked with DVCPro50, only DigiBeta and certainly in post for things like keys 4:2:2 sure is much better. However I wouldn't be too hard on DV, the DV conversions I've made from the same DB tapes look pretty fine. In fact by the time it's encoded for DVD it's pretty damn hard to tell the DB sourced material from the DV conversion of the same material.
However (big however) I'm working in PAL where the 4:2:0 DV sampling is very close to the 4:2:0 sampling used on all DVDs, I'd suspect working in NTSC there maybe a more dramatic difference.

Robert Lane · January 31st, 2006, 11:54 AM

The "bees knees"? Suddenly I feel the need to pollenate something...

These results aren't surprising and solidify what I've always said about digital imaging: Color is more important than resolution.

In fact, I'd rather have an HVX shooting DVCPRO-50 than an H1, Z1 or HD100 shooting HDV; you just can't beat Panasonic out-of-the-camera color.

Barry Green · January 31st, 2006, 12:57 PM

Quote:

Originally Posted by R Geoff Baker

2 I would guess that the right hand is 'flapping' in the 4:1:1 shot and so an awful lot of what we are seeing is motion artifacting/interlace converted to stills problems

Nope. This is from a 24P sequence and there is no interlacing of any type, and I chose frames that were roughly comparable where the flapping had stopped.

I'll do a still life shot later with some color items.

R Geoff Baker · January 31st, 2006, 04:03 PM

Thanks for the clarification, Barry. I'd have said that the vertical resolution appeared halfed -- exactly what happens when a codec like DV25 does when faced with significant changes between fields. But you would know better than I how these frames are shot, how the stills were grabbed, and why the vertical resolution fails so miserably in the example posted.

Perhaps a better way for me to state my wish is that both frames _were_ the same -- although you indicate they were taken only a short time apart, the one frame 'captures' motion & the other doesn't ... and the problem revealed is in precisely the area where motion was present. It would be educational to see how the DV50 codec stood up to the same motion, or conversely to see how the frames compared if no motion was present in either.

I am happy to stipulate that DV50 is better than DV25 -- just a pedant about what the evidence presented reveals & doesn't.

Cheers,
Geoff Baker

David Saraceno · January 31st, 2006, 04:08 PM

I'm a skeptic, but the photos don't lie.

How much do you attribute to 4:1:1 versus 4:2:2?

R Geoff Baker · January 31st, 2006, 04:19 PM

The photos aren't lying, but neither are they photos of the same event ...

GB

Dan Euritt · January 31st, 2006, 05:18 PM

thanks for the post barry!

Barry Green · January 31st, 2006, 08:26 PM

Quote:

Originally Posted by R Geoff Baker

The photos aren't lying, but neither are they photos of the same event ...

GB

They couldn't be photos of the same event because they are the same camera.

There's no interlacing going on, these are progressive captures.

I'll do some still-life stuff later, non-green-screen stuff.

R Geoff Baker · January 31st, 2006, 09:31 PM

Some years ago DV magazine did a stress test of popular digital codecs compared to Betacam -- they used a repeated motion event to create a 'same event' comparison -- a merry go round or some such. A table top version of the same would make a perfect 'still life' sized equivalent, if you are so inclined.

I remain convinced I'm seeing a halfed vertical resolution in the motion area of the DV25 image ... how exactly is the 'progressive' nature of that recording created?

GB

Barry Green · January 31st, 2006, 09:48 PM

Scanned off the CCD progressively, recorded as 24P carried within a 60i stream. Imported to Vegas where the pulldown is removed, resulting in restoring the original 24P frames. Frame was copied to the clipboard and then pasted into PhotoShop.

Marty Hudzik · January 31st, 2006, 10:46 PM

Quote:

Originally Posted by Barry Green

Scanned off the CCD progressively, recorded as 24P carried within a 60i stream. Imported to Vegas where the pulldown is removed, resulting in restoring the original 24P frames. Frame was copied to the clipboard and then pasted into PhotoShop.

Barry,
Can you give me a quick rundown on how you use DV50 in vegas and what codecs or add-ons you used? Also.....can you preview out via firewire to an NTSC monitor? If so is it downsampled to DV25?

Thanks

January 31st, 2006, 03:59 AM	#1
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	DVCPRO50 vs. DV Thought you might like to see how much of a difference it makes to shoot in DVCPRO50 mode vs. standard DV mode, on the same HVX. We were shooting some greenscreen tests, and we shot the exact same subject in the exact same lighting with the exact same camera on the exact same settings; the only thing that changed was I changed the recording format from DV to DVCPRO50 and then had the actress do the same actions. Here's an uncompressed frame extraction from the familiar DV that we all know (4:1:1 color sampling): http://www.fiftv.com/HVX200/DV25-Green.png Here's 4:2:2 DVCPRO50: http://www.fiftv.com/HVX200/DV50-Green.png And if you want to see the images blown up, here's an extraction of her right hand at 400% size: http://www.fiftv.com/HVX200/DV25-vs-DV50.png Remember, absolutely nothing else changed. These shots were taken within seconds of each other. This is not trying to compare one camera against another; these shots were taken on the same HVX200. The only change whatsoever was to change the recording format from DV to DVCPRO50.

January 31st, 2006, 11:54 AM	#6
Robert Lane Go Go Godzilla Join Date: Nov 2004 Location: Scottsdale, AZ USA Posts: 2,788 Images: 15	The "bees knees"? Suddenly I feel the need to pollenate something... These results aren't surprising and solidify what I've always said about digital imaging: Color is more important than resolution. In fact, I'd rather have an HVX shooting DVCPRO-50 than an H1, Z1 or HD100 shooting HDV; you just can't beat Panasonic out-of-the-camera color. __________________ Robert Lane Producer/Creator - Bike Pilots TV

January 31st, 2006, 05:42 AM	#2
R Geoff Baker Major Player Join Date: Jan 2005 Location: Ottawa, ON Posts: 471	Thanks for your posting, but a still life would be more indicative -- I would guess that the right hand is 'flapping' in the 4:1:1 shot and so an awful lot of what we are seeing is motion artifacting/interlace converted to stills problems -- or at least so I would have to assume. Maybe a nice bowl of fruit with a shiny can of Coca Cola and a spray of delicate flowers against a textured background would help .... Cheers, GB

January 31st, 2006, 07:02 AM	#3
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	" but a still life would be more indicative " with my experience with DVCpro50, i beg to differ...motion artifacts in DV are pretty appalling, but those same shots with DVCPro50 can look stunning... even this grab as an example.. look at the jaggies on DV... and colour... well it doesnt need commentary... A still life, shot for 15seconds would be a better indicator of compression motion artefacts, not just a still shot taken from DV... Ive always loved DVCpro50... i always thought it was the bees knees but price was abhorent... Im glad to see the format making headway into "this" market... at least it will be appreciated by those that will be using it the most.. and those that have never used it, will come to appreciate the difference... from the looks of it, not many ppl have used DV50 which prolly explains the lack of interest so far as everyone is focused on DVCProHD...

January 31st, 2006, 07:15 AM	#4
Scott Anderson Major Player Join Date: May 2003 Location: Phoenix, AZ Posts: 327	But objects in motion are exactly where keying problems occur. That, and those high-contrast diagonal lines that are the cause of obvious blocking in DV. What an amazing difference! Having never worked in DVCPro50, I am wondering if the apparent increase in latittude is simply due to the increased color sampling. I noticed in the stills of the lizard sculpture, there was also more saturation and more contrast. It's as if the highlights remain about the same, but the camera digs deeper into the blacks. I would have expected more saturation, but not that much more contrast.

January 31st, 2006, 07:37 AM	#5
Bob Grant Trustee Join Date: Nov 2005 Location: Sydney Australia Posts: 1,570	I've never worked with DVCPro50, only DigiBeta and certainly in post for things like keys 4:2:2 sure is much better. However I wouldn't be too hard on DV, the DV conversions I've made from the same DB tapes look pretty fine. In fact by the time it's encoded for DVD it's pretty damn hard to tell the DB sourced material from the DV conversion of the same material. However (big however) I'm working in PAL where the 4:2:0 DV sampling is very close to the 4:2:0 sampling used on all DVDs, I'd suspect working in NTSC there maybe a more dramatic difference.

January 31st, 2006, 04:03 PM	#8
R Geoff Baker Major Player Join Date: Jan 2005 Location: Ottawa, ON Posts: 471	Thanks for the clarification, Barry. I'd have said that the vertical resolution appeared halfed -- exactly what happens when a codec like DV25 does when faced with significant changes between fields. But you would know better than I how these frames are shot, how the stills were grabbed, and why the vertical resolution fails so miserably in the example posted. Perhaps a better way for me to state my wish is that both frames _were_ the same -- although you indicate they were taken only a short time apart, the one frame 'captures' motion & the other doesn't ... and the problem revealed is in precisely the area where motion was present. It would be educational to see how the DV50 codec stood up to the same motion, or conversely to see how the frames compared if no motion was present in either. I am happy to stipulate that DV50 is better than DV25 -- just a pedant about what the evidence presented reveals & doesn't. Cheers, Geoff Baker

January 31st, 2006, 04:08 PM	#9
David Saraceno Major Player Join Date: Jan 2006 Location: Inland Northwest Posts: 490	I'm a skeptic, but the photos don't lie. How much do you attribute to 4:1:1 versus 4:2:2?

January 31st, 2006, 04:19 PM	#10
R Geoff Baker Major Player Join Date: Jan 2005 Location: Ottawa, ON Posts: 471	The photos aren't lying, but neither are they photos of the same event ... GB

January 31st, 2006, 05:18 PM	#11
Dan Euritt Trustee Join Date: Mar 2004 Location: Carlsbad CA Posts: 1,132	thanks for the post barry!

January 31st, 2006, 09:31 PM	#13
R Geoff Baker Major Player Join Date: Jan 2005 Location: Ottawa, ON Posts: 471	Some years ago DV magazine did a stress test of popular digital codecs compared to Betacam -- they used a repeated motion event to create a 'same event' comparison -- a merry go round or some such. A table top version of the same would make a perfect 'still life' sized equivalent, if you are so inclined. I remain convinced I'm seeing a halfed vertical resolution in the motion area of the DV25 image ... how exactly is the 'progressive' nature of that recording created? GB

January 31st, 2006, 09:48 PM	#14
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Scanned off the CCD progressively, recorded as 24P carried within a 60i stream. Imported to Vegas where the pulldown is removed, resulting in restoring the original 24P frames. Frame was copied to the clipboard and then pasted into PhotoShop.