Stu Minnis
April 18th, 2008, 09:36 AM
I am looking for input on a problem I'm having (or maybe it isn't a problem). When shooting with the XHA1, I sometimes see what looks like a horizontal offset of either the red or green channel. I've attached two frame caps to show the problem. The tree branches are magnified about 400%, but the shot of the Washington Monument is the original frame...though I forgot the correct the pixel aspect ratio. You can only see the problem when you have a high-contrast back lit vertical (in the attachments, the edges of the tree branches against the white stone sill or the edges of the Washington Monument against the sky), and it appears as a band of green on the left side of the vertical and a band of red on the right side.
When I first noticed the problem I thought maybe there was some slight misalignment of the chips, but I've tried shooting test footage with two different XHA1s, and they both do the same thing, which makes me think that this is an inherent characteristic of this camera rather than a problem with my particular camera. However, I'm using footage from this camera in a documentary I'm making with a colleague who shot some B-roll on his little Sony HDV palmcorder. Embarrassingly enough, when we both shot footage of back lit verticals, his shots look great, whereas mine have this slight muddiness about them.
So, two questions:
1) Does anyone know what might be causing this, and is there something I can do about it?
2) Is there anything that can be done in post to clean up such shots. I thought maybe shifting the red channel to the left by one pixel would help, but I can't find a filter in Premiere Pro that will let me do that.
Oh, I should probably add that the footage was shot 1080/60i, and we're editing in native HDV.
Thanks in advance for any help you might be able to give me.
Stu
When I first noticed the problem I thought maybe there was some slight misalignment of the chips, but I've tried shooting test footage with two different XHA1s, and they both do the same thing, which makes me think that this is an inherent characteristic of this camera rather than a problem with my particular camera. However, I'm using footage from this camera in a documentary I'm making with a colleague who shot some B-roll on his little Sony HDV palmcorder. Embarrassingly enough, when we both shot footage of back lit verticals, his shots look great, whereas mine have this slight muddiness about them.
So, two questions:
1) Does anyone know what might be causing this, and is there something I can do about it?
2) Is there anything that can be done in post to clean up such shots. I thought maybe shifting the red channel to the left by one pixel would help, but I can't find a filter in Premiere Pro that will let me do that.
Oh, I should probably add that the footage was shot 1080/60i, and we're editing in native HDV.
Thanks in advance for any help you might be able to give me.
Stu