strange pixel columns on red colors?

C

cigsmcgee

Member
hey everyone, i'm dumping my first feature into dvd architect, vid as mpeg-2 with 2-3-3-2 pulldown, shot on my 100a in 24p squeeze.

the render looks alright, expect whenever there is a large presence of red, on a t-shirt or on text. other colors look fine, im happy with the detail and resolution, but whenever red pops up you can see pixelated columns that fade away once its past the red portion of the field.

what is this and can it be smoothed out? anyone know or seen this before?

the only other problems i have are motion blurs that dont occur in the vegas preview, but am i wrong to assume that this is just one of the natural losses when rendering? the curse of cheap digital?

ive used this board a few times for this feature, and its gotten me this far, and this looks like the last bump in the road.
 
I've had issues with filming anything red, even using red lighting can create pixellation on what it illuminates.

At least it happened on 2 different projects I shot on my DVX. Haven't filmed any red (that I remember) with my HVX. Or if I did, I didn't notice the pixellation.
 
DV (with its 4:1:1 color sampling) doesn't handle pure red or pure blue well at all. Look in the articles section for the article on color sampling to see why.

There's a little bit you can do to fix it; in Vegas try the Chroma Blur filter and blur the chroma horizontally and you may prefer the results.

The HVX uses 4:2:2 color sampling in DVCPRO50 and DVCPRO-HD, which gives it twice the color resolution and largely eliminates the problem. But if you shot with an HVX in DV mode you'd face the same issues., just like any DV camera will have.
 
This is a very well known issue with DV video which uses 4:1:1 color sampling. It's even worse when you go to 4:2:0 MPEG2 for DVD, because the color sampling then becomes 4:1:0. The suggestion to apply the chrom blur filter is the best advice under the circumstances.
 
cigsmcgee said:
hey everyone, i'm dumping my first feature into dvd architect, vid as mpeg-2 with 2-3-3-2 pulldown, shot on my 100a in 24p squeeze.

the render looks alright, expect whenever there is a large presence of red, on a t-shirt or on text. other colors look fine, im happy with the detail and resolution, but whenever red pops up you can see pixelated columns that fade away once its past the red portion of the field.

what is this and can it be smoothed out? anyone know or seen this before?

the only other problems i have are motion blurs that dont occur in the vegas preview, but am i wrong to assume that this is just one of the natural losses when rendering? the curse of cheap digital?

ive used this board a few times for this feature, and its gotten me this far, and this looks like the last bump in the road.
Click to expand...

A few things lead me to ask -- what were your exact settings when you rendered your MPEG for DVD Architect? (I ask because there is no 2:3:3:2 pulldown in MPEG, and also because of the ghosting you're seeing.)

Can you post those?
 
thanks for all the replies guys. i'll try the chroma blur and see what happens.

david, all i know is that in the Render As window, the type is MPEG-2 and the template was for DVD ARCH 24p ntsc widescreen vid stream. video 23.976 fps, 720x480. i guess i just assumed it had the pulldown.

perhaps this isnt the highest resolution render option? i was scrambling to get a dvd ready for submission and read a thread that suggested that templete as the best for the DVD ARCH program. this render has the least ghosting, if im using that term right, as opposed to some others that i tried like .avi, with the 2-3-3-2, which looked pretty bad.
 
Last edited:
almost positive. I watched a tutorial on vegas, posted on this site, a while back right before I started using it and that was definitely one of the things i picked up on, the 24p timeline. won't be able to say for sure for a couple of days, but im fairly certain.

but now that you ask, it is creating some serious paranoid doubt.....get back when i find out for sure.
 
You must log in or register to reply here.
Back
Top