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Old July 3rd, 2006, 09:53 PM   #1
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Magenta at top of screen, green at bottom

Just bought a new HD100U. Picked it up Friday, 6/30. Box and body show an "A", so it has the upgrade. Being an oldschool, BetaSP guy the first step today is to set it up and check alignment.

Using the standard Portapattern grey scale/color alignment chart, the top of the screen is magenta, bottom is green. A sort of S-shaped neutral balance strip runs through the center. It's consistent through 5600K preset, 3200K preset and autowhite in each. Shut down and restart, camera hot, camera cold.

This is easily visible in the viewfinder, fold out monitor, broadcast monitor, FCP screens and FCP scopes. As I don't seem to be able to post images here, I can email a frame from FCP of scope and the chart chart to anyone who would like to see it. The scope shows spikes pointed straight toward magenta and green, instad of the tight white ball it should show on a proper camera setup.

In broadcast camera speak, the technical term would be "broke". Is this normal for the HD100U or did I just get a bad one?

Any advice would be appreciated.

George
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Old July 3rd, 2006, 10:35 PM   #2
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White Balance

Quote:
Originally Posted by George Strother
Just bought a new HD100U. Picked it up Friday, 6/30. Box and body show an "A", so it has the upgrade. Being an oldschool, BetaSP guy the first step today is to set it up and check alignment.

Using the standard Portapattern grey scale/color alignment chart, the top of the screen is magenta, bottom is green. A sort of S-shaped neutral balance strip runs through the center. It's consistent through 5600K preset, 3200K preset and autowhite in each. Shut down and restart, camera hot, camera cold.

This is easily visible in the viewfinder, fold out monitor, broadcast monitor, FCP screens and FCP scopes. As I don't seem to be able to post images here, I can email a frame from FCP of scope and the chart chart to anyone who would like to see it. The scope shows spikes pointed straight toward magenta and green, instad of the tight white ball it should show on a proper camera setup.

In broadcast camera speak, the technical term would be "broke". Is this normal for the HD100U or did I just get a bad one?

Any advice would be appreciated.

George
George, any change when you do a manual white balance on your greyscale chart?

Do you get an "OK" prompt or any other message?

If the white balance is successful, what color temp. does the camera indicate?
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Old July 3rd, 2006, 10:45 PM   #3
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This happens on the stock lens when it is at F1.4 (full open.) It is chromatic abberation and I have found that I can make this phenomenon happen on different stock lenses.
For the most part you will never notice it, but it is highly visible on white flat objects like charts or even a gray card.
Try to shoot in the "sweet spot" of the lens at F4.
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Old July 4th, 2006, 12:25 AM   #4
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Quote:
Originally Posted by Carl Hicks
George, any change when you do a manual white balance on your greyscale chart?

Do you get an "OK" prompt or any other message?

If the white balance is successful, what color temp. does the camera indicate?

Under quartz, manual white balance gives a message -

Auto White B
OK [3200K]

Earlier, window light, manual white -

Auto White A
OK [5200K]

Always Magenta on the top, green on the bottom.
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Old July 4th, 2006, 12:34 AM   #5
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Quote:
Originally Posted by Tim Dashwood
This happens on the stock lens when it is at F1.4 (full open.)
Still there at 2.8, 4. At 5.6 still magenta on top, less green on the bottom.

On the FCP vectorscope, no gain on the scope of course, the magenta burst breaks the 20 ring, green nearly touches the 20.

This is with the stock lens.

Would you consider this normal or should I have it checked?
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Old July 4th, 2006, 11:20 PM   #6
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Quote:
Originally Posted by George Strother
Still there at 2.8, 4. At 5.6 still magenta on top, less green on the bottom.

On the FCP vectorscope, no gain on the scope of course, the magenta burst breaks the 20 ring, green nearly touches the 20.

This is with the stock lens.

Would you consider this normal or should I have it checked?
George, if you feel that there is a problem with the camera, and you bought a new unit, you are able to exchange it for a new unit. JVC offers a 30 day initial failure policy. You do this exchange through your dealer, or through JVC directly. Either contact your dealer and ask for an exchange, or follow the instructions on this website:

http://pro.jvc.com/prof/support/pepolicy.jsp

Regards, Carl
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Old July 5th, 2006, 02:06 AM   #7
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Is it magenta? or red? Mine's magenta, but there's much more red than blue.

I ran into something similar this weekend. I think it's from the lens as well, but it's in the horizontal direction.

http://angrysock.com/ih/HDCAM-RGB24-sample.png
That's from the F900 BTW.
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Old July 5th, 2006, 10:01 AM   #8
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Thanks to everyone for the quick replies.

Carl - I'll contact my dealer this morning and see if I can stop by and run the same tests on his demo unit. As Tim pointed out, this may just be normal behavior on 1/3" chip HD cams using this chart. I haven't checked any others. JVC's exchange policy is terrific though, if I need it. I appreciate your responses.

Tim - You have tons of experience with these cams, I have zero. Do you think its normal for the magenta/green to hang on through 5.6, using the Portapattern grey scale/color alignment chart?
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Old July 5th, 2006, 11:07 AM   #9
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Quote:
Originally Posted by Chris Chang
Is it magenta? or red? Mine's magenta, but there's much more red than blue.

I ran into something similar this weekend. I think it's from the lens as well, but it's in the horizontal direction.

http://angrysock.com/ih/HDCAM-RGB24-sample.png
That's from the F900 BTW.
That is typical chromatic abberation. It happens on all cameras with all lenses, but just at varying degrees depending on optical quality, focal length, type of lens (prime/zoom), aperture, and CCD block/sensor build or density.
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Old July 5th, 2006, 11:10 AM   #10
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Quote:
Originally Posted by George Strother
Tim - You have tons of experience with these cams, I have zero. Do you think its normal for the magenta/green to hang on through 5.6, using the Portapattern grey scale/color alignment chart?
George,

The CA never goes away, it just varies depending on conditions. I would suggest shooting tests on real-world subjects instead of a chart. You will most likely notice it when full open, but you should be happy between F2.8 and F5.6. Don't close down past F5.6 or you risk getting diffraction with the reds.
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Old July 5th, 2006, 11:26 AM   #11
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Quote:
Originally Posted by Chris Chang
Is it magenta? or red? Mine's magenta, but there's much more red than blue.

Vectorscope is pointed straight toward magenta and green on camera.(That should say MY camera)

But your images look like normal CA, a red/magenta band on one side of a sharp brightness transition and a green band on the opposite side. This is common on most digital cameras in extreme contrast areas, even my Canon pro still cameras. Pixel density, chip size and lens quality are all factors in the amount of this type of CA you will see, but you can find it in most digital shots if you zoom in far enough on your screen and check around really harsh transitions.

The problem I am seeing is a large magenta tinted blob area over about a quarter of the screen at the top, just off center and a green tinted blob over about a quarter of the screen at the bottom, more to the left. This is over everything on the chip chart, not just a fringe around transitions. I think we are seeing different problems, or at least different aspects. I have never seen these "blobs" of chroma shift on any camera before.
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Old July 5th, 2006, 11:46 AM   #12
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Quote:
Originally Posted by Tim Dashwood
George,

The CA never goes away, it just varies depending on conditions. I would suggest shooting tests on real-world subjects instead of a chart. You will most likely notice it when full open, but you should be happy between F2.8 and F5.6. Don't close down past F5.6 or you risk getting diffraction with the reds.
Tim -

It looks like we were both answering Chris at the same time.

As you may have seen in my answer to Chris, the problem I am seeing is a magenta tinted area in the upper part of the screen and a green tinted area in the lower part of the screen. This tint is over the grey chips and background, not the CA fring along transition (got that too, of course).

Wierder yet, it would not go away Monday. Camera hot, camera cold, different light souces.

Today I setup the same test and got a nearly perfect chart. I've left the camera on for about an hour, the case is warm, the window lighting has changed, "manual" white for window light or switch lighting and balance for quartz and I still get a pretty much perfect chart. Vectorscope shows shifts toward magenta and green, but not over 5. Not really visible on a color monitor now.

Is there an upper limit to camera hot time or something that would cause a color shift all day one day that would go away two days later?
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Old July 5th, 2006, 12:11 PM   #13
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Here is something to try,

put your gain up at 9db then close your iris until you have perfect exposure.

Can you still see the magenta?

On the occasions I use the hd100 to do aerial telecine 8mm/16mm film transfers, I had noticed the magenta at the top half when viewing some very well exposed black and white film. Having the iris all the way open is what caused it to happen. slightly closing it though fixed it and made the image pure black and white. I found that 9db gain allowed me to close it further while maintaining excellent contrast. 9db is amazingly clean on the jvc. 15db is definitely noisy and 18db is useless imo.
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Old July 7th, 2006, 02:31 AM   #14
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George I know exactly what you're talking about, it's not normal CA
I posted the same thing a while a go, pinkish tinge on the top of the lense while a greenish tinge hangs on the bottom of the lense, it is obvious with white backgrounds, I ended up closing the iris abit more and it seems to have gone away, I had pics to show but now are off my server, can you send me some pics of the tinge? I don't think it's the camera so who do we call to replace our fujinon lenses? (if thats applicable)
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Old July 7th, 2006, 03:49 PM   #15
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Others have talked about this too.

with the iris all the way open, you get that magenta tinge near the top half.
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