Artifacting normal on HD100

Joel Aaron · March 28th, 2006, 01:14 AM

Quote:

Originally Posted by Peter Dolman

Joel
I found too that keeping the exposure up near 100

I'm not sure I understand this... are you saying Zebras are at 100 and you're putting the highlights very near 100?

Peter Dolman · March 28th, 2006, 01:16 AM

Daniel

these tests were done today in response to Mikael's posted concerns
I have been aware of the effective differences in the detail settings for some time now but I was not fully appreciative of the differences until I completed this test earlier today - those shots speak for themselves

all shots were ingested at "medium" cineform settings

no probems yet with 2.0, although I haven't completed anything beyond 30 minutes thus far
cheers
Pete

Peter Dolman · March 28th, 2006, 01:29 AM

quote:
I'm not sure I understand this... are you saying Zebras are at 100 and you're putting the highlights very near 100?

yes, zebras set at 100 ... highlights as close as possible without clipping
I could have gone to F8 and still got a reasonable shot, but I found that keeping it open and towards the lighter side of exposure helped to soften the visible blocking. If I had an ND8 I would likely have opened it up to F4

Daniel Patton · March 28th, 2006, 01:33 AM

Very cool findings Peter, even more so just in time for some pro motocross I'm shooting this weekend! All the fast moving action had me a little concerned with HDV. Thanks for sharing. I may post my results from the race as well

As for the PPro 2, are you on an AMD x64 system or an Intel P4.

Mikael Widerberg · March 28th, 2006, 01:36 AM

Quote:

Originally Posted by Peter Dolman

Joel

exactly that ... I think it's apparent that in a shot like that, anything above minimum detail is going to magnify blocking artifacts
I found too that keeping the exposure up near 100 helps to soften artifacts without losing actual focus ... none of those shots posted were CC ... I could have easily bumped the colors to make a richer scene without bringing in additional blocking

cheers
Pete

Thanks Peter!
Very useful information, I will test that.

Joel Aaron · March 28th, 2006, 01:42 AM

Quote:

Originally Posted by Daniel Patton

Very cool findings Peter, even more so just in time for some pro motocross I'm shooting this weekend!

Post it!

If you can play around a little consider getting some closeups of bikes landing so you can get the dirt/mud flying. Try out the the 50p or 60p modes in SD so you've got some slow motion too. You might try zooming in with a wide aperture and then pulling focus. I bet with some practice you could get it working. Make sure to have some background in there like trees so you can appreciate the shallow DOF.

That should be a great testing ground. Test your black level in advance. In our tests we seem to like -1 or so to avoid crushing detail you may want to see.

Daniel Patton · March 28th, 2006, 01:54 AM

Going way OT here, sorry...

Joel, those are all on my list of things to do... and then some, you are a mind reader no doubt. After shooting all of the GNC/GNCC motos last year with the Canon XL1s and a new 20X lens, i'm looking forward to the JVC / Fugi and overcranking some of the action. I use Paolos DSC settings but with the blacks at 0, even -1 is too crushed for me.

Joel Aaron · March 28th, 2006, 01:59 AM

Quote:

Originally Posted by Daniel Patton

Going way OT here, sorry...
I use Paolos DSC settings but with the blacks at 0, even -1 is too crushed for me.

Cool - yeah... I'm a big fan of getting a wide range too. Ok - back on topic... I'm interested to see if you have HDV issues. Minimum may be the key to artifact free HDV.

Robert Jackson · March 28th, 2006, 08:05 AM

Quote:

Originally Posted by Philip Williams

Well only you can answer that question. On the plus side, the chances that viewers will notice the MPEG artifacts while watching your video in motion (emphasis on MOTION) are extemely low. While an editor sees every frame and srutinizes every pixel, the viewer just won't look at it like that.

Yep. That's pretty much exactly it. I shot a music video about a week ago and so far that's been the only time I've had the opportunity to use my HD100, but I've been reviewing the footage while I'm out on the road doing research for the doc I'm working on. It looks great, but when I capture a frame there will invariably be some area of the frame with blocky compression artifacts. I can't see anything out of the ordinary while the image is in motion, though. And this footage was taken in a little 1000-seat theater in Oklahoma, not on the water or while falling towards the Earth from a plane or any of the other cliche examples of things that stress the HDV codec. It seems to just be a side-effect of crunching the stream down in size, but it seems to be nearly impossible to detect without stopping the stream and examining a single frame carefully.

Peter Dolman · March 28th, 2006, 09:51 AM

My 30p test shots are now posted
all of the same same settings as used in the 24p shots with exception of going to F4 ...
regardless, Barry's suggestion that 24p displays less blocking artifacts seems to hold true ... see for yourself www.vidprostudios.com
click on the small text in the middle of the page "settings" when it first opens
cheers

Barlow Elton · March 28th, 2006, 10:33 AM

Quote:

Originally Posted by Barry Green

Don't know about 1080/24F Canon; I suspect that it will perform more robustly than the 1080/60i version would.

It is slightly better. I know that the Canon's artifacting would look about the same in that scene as the JVC, but with a larger frame. Downsampled to 720p it would probably look slightly better, believe it or not.

For most purposes it doesn't bother me in the least. Do you watch your footage with your face next to the screen or with a magnifying glass? Also, there are ways to massage it in post without softening the picture too much.

If I were shooting something for Discovery HD, I'd tap the SDI so I didn't have anything to worry about. Same with the JVC, tap the analog if it's of utmost importance to avoid any of these kinds of artifacts.

Daniel Patton · March 28th, 2006, 11:23 AM

QUOTE
"Barlow Elton... Do you watch your footage with your face next to the screen or with a magnifying glass"?

DOH! Guilty as charged. hehe... don't we all?

Joking aside Barlow, I would love to have a portable device to capture from the JVC / anolog, it would maybe reduce the face prints on my LCD screen. ;)

Peter, what was your shutter set to on the HD downhill series of runs on your site? It looked like a good balance of motion/action. I tend to push it up around 250 for the motos I shoot.

Mikael Widerberg · March 28th, 2006, 12:59 PM

Here is a short kayaking m2t clip from the wonderfull acipellago in Stockholm.
Filesize: 3.21mb.

http://www.plonk.se/artifacting.m2t

The artifacts in the water is hard to see, but in the sky you can see them quite well.

All settings are at normal, no gain, 25P.

Peter Dolman · March 28th, 2006, 01:09 PM

Quote:

Originally Posted by Daniel Patton

QUOTE
Peter, what was your shutter set to on the HD downhill series of runs on your site? It looked like a good balance of motion/action. I tend to push it up around 250 for the motos I shoot.

Daniel ... a bit OT, but here goes
I was in a hurry that day so I didn't write it all down but I do remember that most of my shots were at 250 shutter. At the time I only had the on-camera ND2, were I to add on the ND6 that I now own, I would have likely gone to variable shutter and dialed it in to 120 or so for a bit shallower DOF on some shots. As you can see, many shots were clipped but I didn't want to shut it down more than F8 and didn't want to go any faster than 250 ... I took the middle road and accepted the outcome. This was all shot at 24p, so I think it turned out okay for my first time out with the new camera on snow. The original full rez footage does not appear as clipped as the down-converted .wmv shown on my site and is of course much richer in it's colors. I threw this piece together in about 90 minutes including ingest time of 40 minutes of footage.
Little to no CC ... had to have it ready for the banquet and awards ceremony soon thereafter
cheers
PS: that was the actual sunrise from my deck that morning

Joel Aaron · March 28th, 2006, 01:09 PM

Quote:

Originally Posted by Mikael Widerberg

Here is a short kayaking m2t clip from the wonderfull acipellago in Stockholm.
Filesize: 3.21mb.

http://www.plonk.se/artifacting.m2t

The artifacts in the water is hard to see, but in the sky you can see them quite well.

All settings are at normal, no gain, 25P.

On my screen it's not that noticeable, I really have to be digging to see this stuff. What was your detail setting? The other water shots with detail at MIN look good.

On the bright side, if you shot a scene like this with an HVX-200 you'd have a screen full of dancing colored noise that would be easy for everyone to see.

March 28th, 2006, 01:33 AM	#34
Daniel Patton Major Player Join Date: Apr 2005 Location: Knoxville TN Posts: 589	Very cool findings Peter, even more so just in time for some pro motocross I'm shooting this weekend! All the fast moving action had me a little concerned with HDV. Thanks for sharing. I may post my results from the race as well As for the PPro 2, are you on an AMD x64 system or an Intel P4. __________________ Our eyes allow us to see the world - The lens allows others to see the world through our eyes. RED ONE #977

March 28th, 2006, 01:54 AM	#37
Daniel Patton Major Player Join Date: Apr 2005 Location: Knoxville TN Posts: 589	Going way OT here, sorry... Joel, those are all on my list of things to do... and then some, you are a mind reader no doubt. After shooting all of the GNC/GNCC motos last year with the Canon XL1s and a new 20X lens, i'm looking forward to the JVC / Fugi and overcranking some of the action. I use Paolos DSC settings but with the blacks at 0, even -1 is too crushed for me. __________________ Our eyes allow us to see the world - The lens allows others to see the world through our eyes. RED ONE #977

March 28th, 2006, 09:51 AM	#40
Peter Dolman Regular Crew Join Date: Feb 2006 Posts: 34	30p tests My 30p test shots are now posted all of the same same settings as used in the 24p shots with exception of going to F4 ... regardless, Barry's suggestion that 24p displays less blocking artifacts seems to hold true ... see for yourself www.vidprostudios.com click on the small text in the middle of the page "settings" when it first opens cheers

March 28th, 2006, 11:23 AM	#42
Daniel Patton Major Player Join Date: Apr 2005 Location: Knoxville TN Posts: 589	QUOTE "Barlow Elton... Do you watch your footage with your face next to the screen or with a magnifying glass"? DOH! Guilty as charged. hehe... don't we all? Joking aside Barlow, I would love to have a portable device to capture from the JVC / anolog, it would maybe reduce the face prints on my LCD screen. ;) Peter, what was your shutter set to on the HD downhill series of runs on your site? It looked like a good balance of motion/action. I tend to push it up around 250 for the motos I shoot. __________________ Our eyes allow us to see the world - The lens allows others to see the world through our eyes. RED ONE #977

March 28th, 2006, 01:16 AM	#32
Peter Dolman Regular Crew Join Date: Feb 2006 Posts: 34	Daniel these tests were done today in response to Mikael's posted concerns I have been aware of the effective differences in the detail settings for some time now but I was not fully appreciative of the differences until I completed this test earlier today - those shots speak for themselves all shots were ingested at "medium" cineform settings no probems yet with 2.0, although I haven't completed anything beyond 30 minutes thus far cheers Pete

March 28th, 2006, 01:29 AM	#33
Peter Dolman Regular Crew Join Date: Feb 2006 Posts: 34	quote: I'm not sure I understand this... are you saying Zebras are at 100 and you're putting the highlights very near 100? yes, zebras set at 100 ... highlights as close as possible without clipping I could have gone to F8 and still got a reasonable shot, but I found that keeping it open and towards the lighter side of exposure helped to soften the visible blocking. If I had an ND8 I would likely have opened it up to F4

March 28th, 2006, 12:59 PM	#43
Mikael Widerberg Regular Crew Join Date: Mar 2005 Location: Stockholm Sweden Posts: 73	Here is a short kayaking m2t clip from the wonderfull acipellago in Stockholm. Filesize: 3.21mb. http://www.plonk.se/artifacting.m2t The artifacts in the water is hard to see, but in the sky you can see them quite well. All settings are at normal, no gain, 25P.