Any colors to watch out for?

Jaime Valles

Jaime Valles

Veteran
Hello, all! I'm interested in the HMC150, and am just curious about the AVCHD compression with regards to certain colors. Right now I shoot with a DVX100 in MiniDV, and I have to be very careful with anything that's bright red, because it pixellates like gangbusters. Looks like a bad 80's video game. The solution is to simply not shoot anything bright red, which is fine most of the time.

Does the HMC150 have any similar issues with red or any other color? Any other visual pitfalls I should be aware of? :dankk2:
 
I threw a bunch of color into the camera for a test shoot 2 weeks ago and was pleasantly surprised by how well this camera deciphered the colors. Lots of Red, Green, and Blue, no problems other then a few soft focuses in the low light.

http://www.vimeo.com/3903280
 
I'm not real experienced with the nuances of this camera yet so I'm sure I could have had better results with different settings, but I will say I have had red 'blowouts' shooting someone wearing red at sunset, using a scene file ('spark') that exaggerates colors. I'm not sure how the stock scene file would have behaved -- undoubtedly it would have behaved a little better.

Take a look:

» http://allenellis.com/public/hmc150_blow_reds.mp4
1.4MB Quicktime MP4

The blocky artifacts are due to compression. But those colors are pretty much what came out of the camera.
 
jrv3034 said:
Hello, all! I'm interested in the HMC150, and am just curious about the AVCHD compression with regards to certain colors. Right now I shoot with a DVX100 in MiniDV, and I have to be very careful with anything that's bright red, because it pixellates like gangbusters. Looks like a bad 80's video game. The solution is to simply not shoot anything bright red, which is fine most of the time.

Does the HMC150 have any similar issues with red or any other color? Any other visual pitfalls I should be aware of? :dankk2:
Click to expand...



Just FYI, a 4:1:1 color smoothing filter will almost always take care of this in your DVX footage....
 
There are no "issues" with colors on the HMC. If you get everything right -- the basics like exposure and white balance -- and the advanced functions in the scene files -- you can capture some truly great images.

The complaint from TigerFX about the "Spark" scene file relates to the default Chroma Level (+4). You can lower that by one or two -- but the problem he reports may very much relate to the display he's using.

I wasn't a DVX user -- but my guess is that your problem relates to your camera settings. But, of course, i could be wrong -- and perhaps DVX users around the world were avoiding colors.

The bottom line is that the answer to your question is -- no.
 
Thanks for the footage BluePatriot, TigerFX & D.R. Gates.

TigerFX, I think that's similar to what happens to the DVX100. More experimenting would be needed to see if it's actually the same type of artifact.

There are no "issues" with colors on the HMC. If you get everything right -- the basics like exposure and white balance -- and the advanced functions in the scene files -- you can capture some truly great images.

The complaint from TigerFX about the "Spark" scene file relates to the default Chroma Level (+4). You can lower that by one or two -- but the problem he reports may very much relate to the display he's using.

I wasn't a DVX user -- but my guess is that your problem relates to your camera settings. But, of course, i could be wrong -- and perhaps DVX users around the world were avoiding colors.

The bottom line is that the answer to your question is -- no.
Click to expand...

Well, it's not a settings issue. It's a compression issue. MiniDV records DV25 in 4:1:1, which destroys certain colors, specifically red. There are some examples of stills on THIS thread that illustrate the problem that the DVX has, as well as any other standard definition MiniDV camera.

I'm just wondering if the HMC150's 4:2:0 AVCHD suffers from the same color compression issues as 4:1:1 DV25.

Just FYI, a 4:1:1 color smoothing filter will almost always take care of this in your DVX footage....
Click to expand...
Ullanta, indeed you are correct, and that's what I do when I'm working with the footage myself in the editing room. But when I'm shooting for clients who wants the tapes at the end of the shoot, just I try to avoid shooting anything bright red, so they don't ask "what's wrong with her skirt?"
 
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Yes, 4:2:0 and 4:1:1 will have the same amount of chroma decimation and the same amount of artifacting, it'll just be in a different shape. 4:1:1 causes wide thin blocks of chroma, 4:2:0 causes square blocks. Shoot something all-red and your resolution will drop significantly. Moreso in 720p than in 1080p, and worst in 1080i.

If you're downconverting to SD, you have nothing to worry about. If you're delivering in HD, shooting an entire concert or theater presentation under a wash of red or blue light will result in fuzzy footage in any 4:2:0 codec, whether XDCAM-EX, AVCHD, AVC-Intra50, or HDV.

It's the same thing with 4:1:1, but a different shape. Because of the square nature of the chroma sampling, you may not notice it as much.
 
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