Tearing Red: Something Wrong with the Camera?

U

ulysseshead

Member
Hey all.

I posted something about this earlier and scrapped it thinking I found the issue. BUT it turns out I'm still seeing the red tearing in my footage. This was shot SD and it happens with HD as well. You can see from the outlined sections, the reds are really bad and the footage is obviously not overexposed. Is there something wrong with my camera?

1)
capture1.jpg

2)
capture3.jpg

3)
capture4.jpg
 
Thats a result of the 4:2:0 and 4:1:1 color space ofthe HDV and DV codecs, respectivly. They dont have enough color resolution to show the saturated reds with clean edges. There are things you can do to lessen the effect. Turn the "chroma" down. that can reduce the prominence of the red bleed. There isnt much more you can do, its inherent in the Codec.
 
Yes, I concur with Timur. It is an unfortunate side effect of the colorspace. It is not present on all reds, just a certain range and it looks like you found one of them :(
 
I wonder is the AVC-HD codec handles reds better than HDV.

Also, is it less prominent on HDV material as the 4 pixel color block is much smaller on a HD screen? Steven?
 
AVC-HD is going to be exactly the same, it's also 4:2:0.

As for more/less prominence: at the same pixel-for-pixel size the chroma sampling will be equally visible; but if you're looking at HDV on a 24" screen vs. DV on that same 24" screen, yes the HDV will have much smaller 4-pixel blocks.
 
Hmmm ... as usual I'm confused. I still haven't got my head around all the color space stuff, though I do understand the color space on my camera is something I can't change.

Regarding Timur's point: I'm looking though the settings of the presets (I have loaded 5248 FILM from the preset sticky) and I don't see a CHROMO setting to be able to fuss with. Is there any way around this? disjecta suggested I had found that a particular shade of red that would cause this, but it seems to be across the board I have bleed on reds. Do other A1 users have this problem? This seems a serious drag to me.

Lastly, regarding Barry's comment, I should shoot only in HD and that will diminish this issue?
 
Look in the "articles" section for an article on understanding color sampling; once you know how it works you'll understand more about what's happening to you and why yes, every HDV and DV and AVC-HD camcorder is going to have the issue. The issue will be particularly noticeable if you have areas of where a red or blue color merges with a different color; having a diagonal stripe of red and green side-by-side would probably be the worst case example.
 
I found the Chroma; it's just not with the custom presets.

SO ...

I went back to Barry's article on the A1 v. HVX and looked at the captures. You can definitely see the red bleeding on the A1 in the car brake lights and stop lights. Unfortunately the comparable still of the HVX has only one red stop light--but no bleed. Wow. I gotta say I'm really bummed. I went from an old, little Sony DV to the A1 and knew nothing about HD and good video and all that. Chalk this up to another lesson learned and I foresee a HVX somewhere in my future.

Thanks for your help guys!
 
well dont discredit the a1 too much. ITs has advantages over the HVX too. you can record HD, thats a touch sharper, for an hour, at about half the cost.....

But the benefits of the P2 PAnasonic system is things like eliminating the chroma bleed, and no temporal artifacts. ITs a trade off. The system at this pricepoint has to flex somewhere....
 
That is true about the price, which is why I went with the A1 based on the many good reviews; I just didn't yet understand the difference the color space would make.

Now are you saying the it's the recording of the image to tape that creates this issue? I plan on getting a firestore very soon ... would that eliminate the bleed prob, still going to Quicktime files?
 
If canon were a genius, they would make it out put prores422 over firewire.........

there would be a line around the block..... (granted if it were possible)
 
try a slight chroma blur in your NLE, smooths off the harshness if you're particularly noticing it.

It's really not the end of the world- it's the same as DV has always done, but with 'smaller' blocks (where playback image size is constant).

I consider it a non-issue, unless I'm chroma-keying, but you should know all about that... HD downsampled to 4:4:4 or 4:2:2 SD pulls a fantastic key.
 
If you use FCP, you can use Nattress Film Effects and do a chroma sharpen (uprez) that helps to *perceptually* reconstruct some of the lost chroma info. It doesn't give you more acquisition color, but smooths the effects of chroma loss, which would help in your case here.
 
A little off topic, sorry. Will the new sony XDCAM EX have this problem too? I hear there is little to no hope of it being 4:2:2.
 
Cool. Great tips and I'll give them a try.

Epicedium, I'm not sure what the "keying" means and thus have more reading to do. It's so funny, I just wanted to make some little films and just when I think I got my head around enough of the technology, (start Pacino) it pulls me back in! (/end Pacino.)
 
I'm adding a note here after looking into this further:

Deartifactor plugin from Magic Bullet does a great job of cleaning up the buzzing, or tearing, or hooha, or @#$%#, whatever you want to call it. In case anyone is need of some fix, I suggest giving the plugin a try.
 
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