Weird colour banding!- GY-HD101 at DVinfo.net

Peter Ford · May 30th, 2007, 05:43 AM

Would anyone be able to diagnose the following?

We were testing our GY on an ABC 100 camera crane the other day, and noticed strange colour banding. As you can see, from the following images, theres strange red to green horizontal bands. subtle, but they're there. The problem has remained since removing camera from the crane, and is most noticeable when over exposing, and least noticeable when under exposing the camera. Lens used is the standard fujinon affair that came with the 101

Banding remains regardless of white balance. I've loaded various scene files, and they also remain. The dont move, and are constant.

Initaially i suspected that the servo motor magnets from the crane might have interfered with the camera in some way? Even though i'd expect the motos on a camera crane to be sheilded.

The crane was plugged into the lens servo, to adjust zoom, so is it possible stray voltage could have entered the camera this way and done some damage?

Has anyone had a similar problem?

http://i7.photobucket.com/albums/y27...mus/crane3.png

http://i7.photobucket.com/albums/y27...mus/crane2.png

http://i7.photobucket.com/albums/y27...mus/crane1.png

Any help would be much appreciated

Miltos Pilalitos · May 30th, 2007, 08:29 AM

Hi Peter,

From the frames you posted it is very difficult to diagnose a problem. Can you post some 720p frames?

The only thing i notice that might be an issue is a reddish to greenish gradient from top of the frame to bottom. Is that what you mean?

Gary Morris McBeath · May 30th, 2007, 08:40 AM

Peter,

Do a search for "color banding" or "red gradient" on this forum. You'll find your answer there.

Basically, you can minimise the banding by not shooting wide open; stop down to at least f2.8, preferably f.4.

Gary

Drew Curran · May 30th, 2007, 09:49 AM

Peter
This seems to be a weakness with the stock lens and to a lesser extent the more expensive replacement lenses. The new HD200 series cameras aparently have a built-in feature to compensate for this.

Here is a recent thread here discussing this very issue:

http://www.dvinfo.net/conf/showthread.php?t=93536

Drew

Peter Ford · May 30th, 2007, 10:04 AM

thanks for the replys everyone

Strange- i've used this camera for ages, and i've never noticed it before. It does seem to be lateral chromatic abbervation though- it goes away when i close the iris up.

Hmmm- i might ring up jvc tommorow and see if they're engineers can 'tune' the camera to the lens or something

May 30th, 2007, 05:43 AM	#1
Peter Ford Regular Crew Join Date: Oct 2006 Location: London, uk Posts: 99	Weird colour banding!- GY-HD101 Would anyone be able to diagnose the following? We were testing our GY on an ABC 100 camera crane the other day, and noticed strange colour banding. As you can see, from the following images, theres strange red to green horizontal bands. subtle, but they're there. The problem has remained since removing camera from the crane, and is most noticeable when over exposing, and least noticeable when under exposing the camera. Lens used is the standard fujinon affair that came with the 101 Banding remains regardless of white balance. I've loaded various scene files, and they also remain. The dont move, and are constant. Initaially i suspected that the servo motor magnets from the crane might have interfered with the camera in some way? Even though i'd expect the motos on a camera crane to be sheilded. The crane was plugged into the lens servo, to adjust zoom, so is it possible stray voltage could have entered the camera this way and done some damage? Has anyone had a similar problem? http://i7.photobucket.com/albums/y27...mus/crane3.png http://i7.photobucket.com/albums/y27...mus/crane2.png http://i7.photobucket.com/albums/y27...mus/crane1.png Any help would be much appreciated Last edited by Peter Ford; May 30th, 2007 at 05:48 AM. Reason: to correct my grammer!

May 30th, 2007, 09:49 AM	#4
Drew Curran Major Player Join Date: Jun 2006 Location: N. Ireland Posts: 370	Peter This seems to be a weakness with the stock lens and to a lesser extent the more expensive replacement lenses. The new HD200 series cameras aparently have a built-in feature to compensate for this. Here is a recent thread here discussing this very issue: http://www.dvinfo.net/conf/showthread.php?t=93536 Drew __________________ Pixol www.pixol.co www.facebook.com/pixolmedia www.twitter.com/pixolmedia

May 30th, 2007, 08:29 AM	#2
Miltos Pilalitos Regular Crew Join Date: Sep 2006 Location: Piraeus, Greece Posts: 53	Hi Peter, From the frames you posted it is very difficult to diagnose a problem. Can you post some 720p frames? The only thing i notice that might be an issue is a reddish to greenish gradient from top of the frame to bottom. Is that what you mean?

May 30th, 2007, 08:40 AM	#3
Gary Morris McBeath Regular Crew Join Date: Aug 2005 Location: Steilacoom Washington Posts: 72	Peter, Do a search for "color banding" or "red gradient" on this forum. You'll find your answer there. Basically, you can minimise the banding by not shooting wide open; stop down to at least f2.8, preferably f.4. Gary

May 30th, 2007, 10:04 AM	#5
Peter Ford Regular Crew Join Date: Oct 2006 Location: London, uk Posts: 99	thanks for the replys everyone Strange- i've used this camera for ages, and i've never noticed it before. It does seem to be lateral chromatic abbervation though- it goes away when i close the iris up. Hmmm- i might ring up jvc tommorow and see if they're engineers can 'tune' the camera to the lens or something