Magenta at top of screen, green at bottom

[Mark Silva]

Something I keep forgetting to mention.

I have seen the magenta at the upper half on other cameras as well.

I have footage from a Sony F900 (the block version/head only) that was used to get all the aerial footage for the olympics. There is some that clearly has that magenta tinge, so I don't think its just a "jvc thing."

[Greg Boston]

Gentlemen,

I have recently learned that this phenomenon is called 'white shading' the problem is described exactly as you are seeing it.

I have also learned that higher end cameras like the one I just got, allow for the creation of lens files which allow you to crank in offsets for individual lenses.

Here is a brief excerpt from the Basic Camera Technology document produced by Sony.

[Nate Weaver]

Greg, that doc was linked in the XDCAM forum and I read to that part about a week ago.

Everytime I saw this thread in the last week, I went searching for the link to this doc!

Anyway, glad you saw it too. Back in September when I posted some downtown Los Angeles clips, somebody spotted it on one of my shots and we were at a loss to explain it other than I noted that it was a green tinge on the bottom of white speckles in the roadway, and a magenta tinge on the top of the speckles...rather than an all over gradient cast.

At the time I wrote it off to the lens, as everybody was just learning about the limitations of the lens.

[Greg Boston]

Originally Posted by Nate Weaver

Greg, that doc was linked in the XDCAM forum and I read to that part about a week ago.

Everytime I saw this thread in the last week, I went searching for the link to this doc!

Anyway, glad you saw it too. Back in September when I posted some downtown Los Angeles clips, somebody spotted it on one of my shots and we were at a loss to explain it other than I noted that it was a green tinge on the bottom of white speckles in the roadway, and a magenta tinge on the top of the speckles...rather than an all over gradient cast.

At the time I wrote it off to the lens, as everybody was just learning about the limitations of the lens.

Nate, according to this..it is the lens and the offets apply a parabolic correction curve to the while balance on the amplifiers.

Now the question becomes...does the HD100 have lens files? Maybe Carl Hicks can help us out here. It may be a factory calibration thing.

-gb-

[Nate Weaver]

Ooops, didn't read far enough into it. I saw the bit about the prism block and just left it at that.

Lens files on the HD100? Heh. Seriously doubt it. I know there's nothing like that in the end-user menus. I'll go out on a limb as speculate that that sort of correction takes serious DSP that only higher level cameras can afford.

[Mark Silva]

I have noticed this rears itself when the iris is all the way open, even if your
exposure is perfect, it happens with it all the way open.

I wish I could have it all the way open and not have this occur.

[Brian Drysdale]

Originally Posted by Greg Boston

Nate, according to this..it is the lens and the offets apply a parabolic correction curve to the while balance on the amplifiers.

Now the question becomes...does the HD100 have lens files? Maybe Carl Hicks can help us out here. It may be a factory calibration thing.

-gb-

White shading is usually found in the maintenance files on the high end cameras. There is a service menu on the HD 100, but you'd really need to know what you're doing before venturing in there.

Since the HD 100 is being used by quite a few people who haven't had training, there's a good chance that any lens file adjustments are hidden in the service menu.

[Greg Boston]

Originally Posted by Brian Drysdale

White shading is usually found in the maintenance files on the high end cameras. There is a service menu on the HD 100, but you'd really need to know what you're doing before venturing in there.

Since the HD 100 is being used by quite a few people who haven't had training, there's a good chance that any lens file adjustments are hidden in the service menu.

It's actually part of the top level File menu on my Sony F350. But yeah, I am thinking as I wondered earlier that on the HD100 it's going to be a factory calibration type thing if it exists. That's definitely something for a service menu.

-gb-

[Brian Drysdale]

Originally Posted by Greg Boston

It's actually part of the top level File menu on my Sony F350. But yeah, I am thinking as I wondered earlier that on the HD100 it's going to be a factory calibration type thing if it exists. That's definitely something for a service menu.

-gb-

Yes, for the lens. There are also adjustments for the CCD block.