Artifacting in Video

[James Miller]

Rick, I agree with the hot red issue with the XL2, but this is not the problem with the clip.

This advert clip is showing the effects of interlaced captured clips 60/50i. The source clips need to be de-interlaced first or shoot in the 24/25p mode.

If you the 60/50i source clip at 100% resolution on your LCD computer screen you will see interlaced lines.

[Jarrod Whaley]

Originally Posted by James Miller

the hot red issue with the XL2

This is not an issue with the XL2, it's due to the 4:1:1 chroma subsampling used by the DV format. Blocky reds can be more visible on the XL2 if you're using certain camera settings, because doing so pushes the camera beyond what the recording format it uses can handle. Don't fault Canon if you must find fault--fault the engineers who designed the DV standard in the 1990's, if anyone. In their defense, DV was designed to be a consumer format, and no one really had any idea at the time that professionals would end up using it. What this means is that there are certain nasty things that we have to work around unless we want to shell out for cameras that use a more capable format. The way in which DV handles reds and oranges is one of those nasty things.

The partial solution to the issue, as others have noted, is to turn down the color gain and/or red gain in shooting situations where you're likely to encounter this problem. As one poster suggested, a better solution is to simply use some chroma blur in post, but this will only work if you're rendering directly from your timeline into some format other than DV--one that doesn't subsample chroma information in 4:1:1 (like WMV, DVD MPEG-2, etc.). If you apply chroma blur and render back to DV again, the "blockies" will simply reappear just like before.

Also note that the problem we're discussing here will show up differently on a TV than it will on a computer monitor: on the TV, you'll see a "blooming" "aura" of red around the affected area, while on a monitor, you'll get the blockiness we've been talking about.

[Jack Barker]

Originally Posted by Jarrod Whaley

This is not an issue with the XL2, it's due to the 4:1:1 chroma subsampling used by the DV format. Blocky reds can be more visible on the XL2 if you're using certain camera settings, because doing so pushes the camera beyond what the recording format it uses can handle. Don't fault Canon if you must find fault--fault the engineers who designed the DV standard in the 1990's, if anyone.

Jarrod - I didn't see James' remark as being critical of Canon, or finding fault with anyone. The OP shot the offending footage on an XL2, and I saw James' comments to be a simple reference to that.

[Jarrod Whaley]

He said that reds were an "issue with the XL2." I was simply pointing out that that reds are an issue with the DV standard.

[Rick Patterson]

Hey fellas,

Thanks again for the assist. I must say however, I've never experienced this issue with the Sony PD-150/250 – as suggested isolating this issue to the DV standard.

I still find it ponderous that the XL2 artifacting occurs so prominently in areas where red is not in high saturations to begin with (I’ll upload another example of this issue in strong blue areas). I hope to do some tests over this weekend and see if I can simply shoot in factory default and tweak the footage in post – obviating the need to adjust those settings every time I change lighting situations.

I wonder for the sake of attempting to create a “run and gun” setting or two for myself, can I use a consumer LCD TV? My funds are currently allocated for deployment of my signage network right now – a 2K field monitor is not within my reach at the moment.

My shooting situations as I’ve previously mentioned are dramatically inconsistent to a fault; in and out of business locations – tungsten to God’s own grid-lighting system. It’s tough enough to meet the client, set up, unpack, think about the shots (I believe in pre-editing the piece in my mind before the shot), set exposure, depth of field, etc. etc. to be hassled with tweaking those darned settings – just not practical in my case.

I’d really love for the XL2 to suit my shooting needs by virtue of using the default settings and tweaking in post or by finding a decent median preset whereby I can “run and gun” and still acquire good quality, multipurpose footage. After all, I just blew over 4K on this puppy with the case and batteries, etc. And yes, I realize some broadcast lenses cost in excess of 4K, but I’m not shooting for Discovery’s Planet Earth here!

I do wonder however, other than the PD-170, which quite frankly is too small for me – I need a shoulder cam; is there a decent sub 5K or mid 5K cam which requires less setting romancing with respect to my shooting requirements, i.e. JVC DV5100U?

Here’s another recent example of the artifacting – notice the stair-stepping on the gent’s blue sleeve cuffs:

http://rapidshare.com/files/36209112/wilson2.wmv.html

Thanks again,

RP

[Jarrod Whaley]

Originally Posted by Rick Patterson

Hey fellas,

Thanks again for the assist. I must say however, I've never experienced this issue with the Sony PD-150/250 – as suggested isolating this issue to the DV standard.

As I was saying before, the issue is more visible on an XL2 sometimes because of the amount of control you have over the way color is reproduced. If you adjust an XL2 so that the image resembles what you'd get from one of the Sonys, I'll betcha the reds in each of the images end up looking pretty similar.

Blocky colors are a compression issue (they are a result of 4:1:1 chroma sampling--color pixels are bigger than light pixels, to phrase it in layman's terms). Sony DV cameras and Canon DV cameras use the same compression scheme--DV. Follow the syllogism to its logical conclusion. :)

[Rick Patterson]

Well, let's see down which path this syllogism takes us. ;-)

I'm still open to suggestions regarding replacement or median / multi-purpose setting(s). I still see other issues with this camera which I'll reveal shortly - not as a critisism, but in search of solution(s).

For the short term I've gotta make due with this camera and get it to work - I done hocked my Sony Gear.

RP