Reds on DVX making ME Red!!!

Kaz

Kaz

Well-known member
Please...to all the DVX gurus out there....help me, before I slit my wrists while jumping off a cliff!

When I play the below samples from my DVX to my production monitor, it looks fine.

However, when I play the same thing while capturing, I get those damn blocking artifacts which is NOT a preview anomaly but now, in fact, embedded in my video.

red1.jpg

red2.jpg


Actually, these pics don't do it justice. You should see this in motion on a big screen HDTV. It's sickening. Making it into an MPEG2 only worsens the problem (even at the highest bit rate).

I normally capture in Vegas 5 but have also tried Avid Xpress 4 along with a host of different codecs. Both programs give me the same thing. I have also tried every in-camera setting known and nothing will quell the blocking.

Am I missing something here, or does everybody have this problem?

Thanks for listening. I love you all.
 
Re: Reds on DVX making ME Red!!!

Looks like your reds are out of gammut. This actually isn't so much a DVX problem as it is a DV problem, I have seen it on other DV footage taken from other cameras. You can desaturate the reds a little and that will help, but probably not get rid of it completely. The best thing to do is to be careful when shooting things in bright red with high contrast areas around them. The panasonic can capture such punchy colors that the DV codec actually has problems when compressing them.
 
Re: Reds on DVX making ME Red!!!

i had the same problem on my XL-1... DV just doesn't like red, especially when areas around the red are dark. i shot a live arena concert once and all the lights went out except for the red spot lights. GOD!!! it was horrible, everything shimmered and danced. yuk. won't do that again. :P i did, however, learn that on the XL-1, if you increase the gain, you increase the problem. did you shoot this footage with the gain at 0?
 
Re: Reds on DVX making ME Red!!!

Just about ALL video doesn't like red. I worked for a while at Discovery international QCing all their programming before broadcast and just about every third vendor tape we received was outside legal broadcast limits for either chroma or luminance.

Luminance was always a problem with analogue tapes, but red chroma flagging seemed to be pretty universal across all the NTSC video formats.

PAL tapes never really seemed to have the same issues, of course.
 
Re: Reds on DVX making ME Red!!!

Kaz,
The Pana is indeed, the worst offender among similar camcorders in this regard. The reds and oranges just explode.
Download the free color adjustment plug-in for Vegas listed on these forums or the Creative Cow; it's called "adcc6" (I think). I've used it to drop the red channel on several "hot" scenes with great effect. Much easier than the built in color corrector in Vegas. You can drop the reds to 80-85 on the vectorscope in Vegas in real time as you watch the output on your (hopefully properly set up) monitor.
There is no camera adjustment that will help you in this case.
Hope this helps.
Ken
 
Re: Reds on DVX making ME Red!!!

Thanks for the responses guys. I'll download that plug-in and be a little more selective in what I shoot. It just pains me to have to avoid most reds as it's my favorite color.
 
Re: Reds on DVX making ME Red!!!

The issue is 4:1:1 compression and the fact that there's 1/4 as much color information as black and white info. That and the dvx loves over-saturating reds.

What NLE do you use? Avid smooths reds, Final Cut Pro leaves them looking...well...like this:
411.jpg


This can't be fixed, but it can smoothed a bit. There's some good FCP software that does just that, and even a built in smoother that helps out a bit. Running this before going to MPEG2 should help you considerably if you use FCP. I'll post some frame grabs as examples later, but now I am too tired.
 
Re: Reds on DVX making ME Red!!!

does every thing red always do this in all 100a footage? i just shot tons of red (red rx-8 mostly) last night for the most important scene of my flick. will be editing on fcp hd.
 
Re: Reds on DVX making ME Red!!!

Not everything that's red does this. If it's red against black there's no issue because then you're primarily dealing with a difference in luminosity values which are sampled at 4 times the rate of color.

Red against another color of similar brightness loves to do this, but it's not an unsolvable issue. Is your distribution method the internet, DV tape, or DVD? Depending one which medium you choose to distribute with, there are ways to fix this pretty considerably.

I'm not at home, now, but later today I'll post some screen grabs as examples.
 
Re: Reds on DVX making ME Red!!!

FCP 4, raw footage:
red.jpg

FCP 4, footage with 4:1:1 compression smoothing filter.
red2.jpg



Graeme Nattress's G-Nicer is supposed to do an even way better job.  The second image still has color issues....the edges are too stoft.  Apparently G-Nicer provides very sharp edges.
 
Re: Reds on DVX making ME Red!!!

Under keying, in versions 4 and after. Oddly enough, it seems the dvx and most other dv devices MAY automatically do this to your video when you play it back from the vtr. The pixellation is re-introduced after you render to dv, anyhow. So ONLY use this for chroma keying or on trouble clips before exporting to MPEG 2 for a dvd...and even then some people say not to use it. Oh, and avid displays images as being smoothed anyhow. DV is weird stuff.
 
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