DVX-100A and bright red objects at DVinfo.net

Bruce A. Christenson · July 3rd, 2005, 05:57 PM

I shot some footage yesterday, and one of my guys was wearing a bright red baseball cap. In almost all of the screencaps I collected today, there is major blurring/compression on the red edges. Is this normal? Is there anything I can do in post or in the future during shooting to prevent this? Avoid St. Louis fans?

I'm using a DVX-100A, Vegas 5.0, screencaps right from the timeline ("best, full").

Examples:

http://www.piousdogproductions.com/jpg/Image6.jpg

http://www.piousdogproductions.com/jpg/Image10.jpg

http://www.piousdogproductions.com/jpg/Image12.jpg

Image indexes go from 0 to 23, in case anyone wants to check out the rest of the screencaps from my shoot.

Thanks,
[bac]

Daniel Runyon · July 3rd, 2005, 09:44 PM

Yessir....Scharky at DVXuser.com discovered that a bit of chroma blur in post does wonders for this.

Ash Greyson · July 3rd, 2005, 11:30 PM

One of the prices you pay for the saturated colors the DVX delivers. XL2 handles these situations much better, but of course, less saturation in general. Both are correctable in post but I generally think it looks better and is more safe to get images to tape more flat and saturate in post....

ash =o)

Bruce A. Christenson · July 3rd, 2005, 11:44 PM

Quote:

Originally Posted by Daniel Runyon

Yessir....Scharky at DVXuser.com discovered that a bit of chroma blur in post does wonders for this.

Thanks, I will see what I can do with it in Vegas, it usually has the important effects!

Daniel Runyon · July 4th, 2005, 02:15 AM

Vegas is me weapon of choice....ye shall indeed find Chroma Blur amongst thine tools.

Barry Green · July 4th, 2005, 05:11 AM

Chroma Blur is an effect added in Vegas 5, so you'll need Vegas 5 or 6.

And this effect happens on all DV cameras, to the extent that the color is pure red or pure blue -- DV video has only 1/4 as much color resolution as it does luma resolution, so pure primary colors (red or blue mainly) will render at low, blocky resolution.. Some codecs do an automatic chroma blur (like Avid), some do none at all (like FCP). Michael Phillips of Avid posted a comparison of the difference between Apple and Avid's DV codec, and you can see how much smoother Avid's displays because of the chroma blurring they employ.

http://24p.com/codecs.htm

Evan C. King · July 5th, 2005, 03:41 AM

So Barry how do you fix that in FCP then?

Barry Green · July 5th, 2005, 12:56 PM

Never used FCP so I don't have a definitive answer.

Understand that the chroma blur is primarily beneficial for display on a computer. When you output back to DV all benefits of chroma blurring will be lost, as the footage will be re-decimated to 4:1:1. Going to DVD should still hold some improvement though, as chroma-blurred 4:1:1 should transfer to 4:2:0 better than raw 4:1:1 does.

For any and all image improvement in FCP, see Graeme Nattress' excellent lineup of image manipulation plug-ins etc. at www.nattress.com.

Ash Greyson · July 5th, 2005, 01:41 PM

Barry is correct... those great popping reds are hard to get to a medium. Gawd forbid you have something end up on VHS! YIKES!! I did one of the first major commerical products shot on DV back in 1997 and learned a lot the hard way. Of course, the cameras are better now but the red especially is a limitation of the format...

ash =o)

Joshua Provost · July 5th, 2005, 05:23 PM

Just to be clear, this is not a problem with the DVX100A, and would not be improved on the XL2. It is a result of the DV format's 4:1:1 color compression, and will be evident on all DV camcorders.

Chroma blur is one way to lessen the effect; intelligent deartifacting (such as Magic Bullet does) is another. Or, try a different format, such as DVCPRO, which stores more detailed color information.

Quick fix: Get the guy a different hat.

Charles Papert · July 6th, 2005, 07:47 PM

I have to disagree that this is purely a DV color sampling issue. From the first time I used the DVX I felt that the reds popped harder than other tones, and certainly more than I was used to with the XL1 series (which is known to be a warm-toned camera, generally indicating that it should deliver more saturated reds, yet it doesn't).

I have become used to adding a specific color correction filter in FCP to my DVX footage simply to desatured the primary reds to bring them in line with the other tones.

I've never gone so far as to compare color charts and do real testing on this--it's just my gut feeling about the images I have made with the camera.

Joshua Provost · July 6th, 2005, 10:38 PM

Charles, I agree with you on the defaults. However, if you increased the saturation on the XL2 and decreased it on the DVX100A, you'd transfer the problem from one to the other.

Everyone needs to understand their camera and set it accordingly, either to capture reality accurately, or achieve some artistic look. You can't rely on default settings. I'm sure you'd agree with that.

Ken Plotin · July 7th, 2005, 10:12 AM

I'm with Charles on this one. The DVX pops reds and oranges more than any DV/DVCAM I've ever used, including the XL1/s and Sony 200/A, 300, 150/170.

I use Vegas 4.0e and the free AaV6cc plug in to correct the red vector only.
Using the built in vectorscope, the uncorrected reds are WAY over 100.
As you drop the red saturation to about 85%, the detail in those oversaturated areas magically reappears. Definitely a quirk in a camera with otherwise excellent colorimetry.
Not to say that the DV format doesn't have color issues because of it's sampling, but this particular one does seem to be DVX specific.

Just my .02.

Ken

Ash Greyson · July 7th, 2005, 02:55 PM

This is my 10th year to shoot DV and I have shot with every camera imaginable and I can tell you this problem is more evident in the DVX than most cameras. It is indeed a general problem as noted above (particularly if you ever use a low shutter) but on the DVX it is worse.

The 1/3" CCD camera that has the most "legal" colors IMHO is the XL2. Film makers and people in general have become obsessed with the saturated look, so much so that a good clean image somehow seems milky or flat.

It is my preference to shoot the cleanest image as close to real life as possible and adjust in post.

ash =o)

Joshua Provost · July 7th, 2005, 04:09 PM

Ash, I'm with you on the point about shooting the cleanest image as possible. However, what cam gives an accurate image at it's default settings? They all need to be tweaked to better reflect reality. They all come out of the box over-saturated, over-sharp, and over-contrasty. Why would someone buy a $3-5k cam and just stick with the defaults? You pay more to get the manual control.

If someone pulls a DVX out the box, shoots something, then asks why they are seeing these artifacts, I put the blame squarely on the operator for not knowing his tools and properly adjusting the saturation (among other things). No offense to Bruce C. who started this thread.

I guess I am just of the blame the operator, don't blame the tool camp.

July 3rd, 2005, 05:57 PM	#1
Bruce A. Christenson Regular Crew Join Date: Jan 2003 Location: Forest Grove, OR Posts: 122	DVX-100A and bright red objects I shot some footage yesterday, and one of my guys was wearing a bright red baseball cap. In almost all of the screencaps I collected today, there is major blurring/compression on the red edges. Is this normal? Is there anything I can do in post or in the future during shooting to prevent this? Avoid St. Louis fans? I'm using a DVX-100A, Vegas 5.0, screencaps right from the timeline ("best, full"). Examples: http://www.piousdogproductions.com/jpg/Image6.jpg http://www.piousdogproductions.com/jpg/Image10.jpg http://www.piousdogproductions.com/jpg/Image12.jpg Image indexes go from 0 to 23, in case anyone wants to check out the rest of the screencaps from my shoot. Thanks, [bac]

July 5th, 2005, 05:23 PM	#10
Joshua Provost Major Player Join Date: Sep 2004 Location: Phoenix, AZ Posts: 493	Just to be clear, this is not a problem with the DVX100A, and would not be improved on the XL2. It is a result of the DV format's 4:1:1 color compression, and will be evident on all DV camcorders. Chroma blur is one way to lessen the effect; intelligent deartifacting (such as Magic Bullet does) is another. Or, try a different format, such as DVCPRO, which stores more detailed color information. Quick fix: Get the guy a different hat. __________________ Owner/Operator, 727 Records Co-Founder, Matter of Chance Productions Blogger, Try Avoidance

July 6th, 2005, 07:47 PM	#11
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	I have to disagree that this is purely a DV color sampling issue. From the first time I used the DVX I felt that the reds popped harder than other tones, and certainly more than I was used to with the XL1 series (which is known to be a warm-toned camera, generally indicating that it should deliver more saturated reds, yet it doesn't). I have become used to adding a specific color correction filter in FCP to my DVX footage simply to desatured the primary reds to bring them in line with the other tones. I've never gone so far as to compare color charts and do real testing on this--it's just my gut feeling about the images I have made with the camera. __________________ Charles Papert www.charlespapert.com

July 6th, 2005, 10:38 PM	#12
Joshua Provost Major Player Join Date: Sep 2004 Location: Phoenix, AZ Posts: 493	Charles, I agree with you on the defaults. However, if you increased the saturation on the XL2 and decreased it on the DVX100A, you'd transfer the problem from one to the other. Everyone needs to understand their camera and set it accordingly, either to capture reality accurately, or achieve some artistic look. You can't rely on default settings. I'm sure you'd agree with that. __________________ Owner/Operator, 727 Records Co-Founder, Matter of Chance Productions Blogger, Try Avoidance

July 7th, 2005, 04:09 PM	#15
Joshua Provost Major Player Join Date: Sep 2004 Location: Phoenix, AZ Posts: 493	Ash, I'm with you on the point about shooting the cleanest image as possible. However, what cam gives an accurate image at it's default settings? They all need to be tweaked to better reflect reality. They all come out of the box over-saturated, over-sharp, and over-contrasty. Why would someone buy a $3-5k cam and just stick with the defaults? You pay more to get the manual control. If someone pulls a DVX out the box, shoots something, then asks why they are seeing these artifacts, I put the blame squarely on the operator for not knowing his tools and properly adjusting the saturation (among other things). No offense to Bruce C. who started this thread. I guess I am just of the blame the operator, don't blame the tool camp. __________________ Owner/Operator, 727 Records Co-Founder, Matter of Chance Productions Blogger, Try Avoidance

July 3rd, 2005, 09:44 PM	#2
Daniel Runyon Major Player Join Date: Dec 2003 Location: The Deep South Posts: 168	Yessir....Scharky at DVXuser.com discovered that a bit of chroma blur in post does wonders for this.

July 3rd, 2005, 11:30 PM	#3
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	One of the prices you pay for the saturated colors the DVX delivers. XL2 handles these situations much better, but of course, less saturation in general. Both are correctable in post but I generally think it looks better and is more safe to get images to tape more flat and saturate in post.... ash =o)

July 4th, 2005, 02:15 AM	#5
Daniel Runyon Major Player Join Date: Dec 2003 Location: The Deep South Posts: 168	Vegas is me weapon of choice....ye shall indeed find Chroma Blur amongst thine tools.

July 4th, 2005, 05:11 AM	#6
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Chroma Blur is an effect added in Vegas 5, so you'll need Vegas 5 or 6. And this effect happens on all DV cameras, to the extent that the color is pure red or pure blue -- DV video has only 1/4 as much color resolution as it does luma resolution, so pure primary colors (red or blue mainly) will render at low, blocky resolution.. Some codecs do an automatic chroma blur (like Avid), some do none at all (like FCP). Michael Phillips of Avid posted a comparison of the difference between Apple and Avid's DV codec, and you can see how much smoother Avid's displays because of the chroma blurring they employ. http://24p.com/codecs.htm

July 5th, 2005, 03:41 AM	#7
Evan C. King Major Player Join Date: Jan 2005 Location: Toronto Posts: 532	So Barry how do you fix that in FCP then?

July 5th, 2005, 12:56 PM	#8
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Never used FCP so I don't have a definitive answer. Understand that the chroma blur is primarily beneficial for display on a computer. When you output back to DV all benefits of chroma blurring will be lost, as the footage will be re-decimated to 4:1:1. Going to DVD should still hold some improvement though, as chroma-blurred 4:1:1 should transfer to 4:2:0 better than raw 4:1:1 does. For any and all image improvement in FCP, see Graeme Nattress' excellent lineup of image manipulation plug-ins etc. at www.nattress.com.

July 5th, 2005, 01:41 PM	#9
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	Barry is correct... those great popping reds are hard to get to a medium. Gawd forbid you have something end up on VHS! YIKES!! I did one of the first major commerical products shot on DV back in 1997 and learned a lot the hard way. Of course, the cameras are better now but the red especially is a limitation of the format... ash =o)

July 7th, 2005, 10:12 AM	#13
Ken Plotin Major Player Join Date: Jan 2004 Location: Los Angeles, CA Posts: 254	I'm with Charles on this one. The DVX pops reds and oranges more than any DV/DVCAM I've ever used, including the XL1/s and Sony 200/A, 300, 150/170. I use Vegas 4.0e and the free AaV6cc plug in to correct the red vector only. Using the built in vectorscope, the uncorrected reds are WAY over 100. As you drop the red saturation to about 85%, the detail in those oversaturated areas magically reappears. Definitely a quirk in a camera with otherwise excellent colorimetry. Not to say that the DV format doesn't have color issues because of it's sampling, but this particular one does seem to be DVX specific. Just my .02. Ken

July 7th, 2005, 02:55 PM	#14
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	This is my 10th year to shoot DV and I have shot with every camera imaginable and I can tell you this problem is more evident in the DVX than most cameras. It is indeed a general problem as noted above (particularly if you ever use a low shutter) but on the DVX it is worse. The 1/3" CCD camera that has the most "legal" colors IMHO is the XL2. Film makers and people in general have become obsessed with the saturated look, so much so that a good clean image somehow seems milky or flat. It is my preference to shoot the cleanest image as close to real life as possible and adjust in post. ash =o)