Mysterious Green Ring at DVinfo.net

Chris Gordon · April 14th, 2004, 03:23 AM

So I just got back from a ten day cruise around the Caribbean & Central America and I decided that this was the perfect voyage to put the HD1 to the test.

The majority of the footage looked pretty good. (With the help of ND filters, a good polarizer, a soft con filter, gradients etc... etc...) Some of the whites looked a little blown out AND I had a few instances with chroma noise issues, but for the most part the footage was acceptable...

EXCEPT... when I shot sunsets. For some strange reason, I got a green ring around EVERY sunset that I shot. Then I remembered a post a few months back with a film producer who noticed the same mysterious green halo around a candle shot in one of his films.

I tried changing WB settings, changing filters - and nothing worked. Is this a shortcoming of the single chip design??

-Chris Gordon
Promo Producer
KABC-TV
Los Angeles

Frank Granovski · April 14th, 2004, 03:56 AM

Could it be the sun's reflection from the filter?

Chris Gordon · April 14th, 2004, 04:02 AM

I shot it every which way you could imagine. One take was "clean" with no filters on the lens. I still got the same result.

I'm trying to figure out a way to post a still shot from the footage so that you all can see what I'm talking about.

Frank Granovski · April 14th, 2004, 04:05 AM

Thanks.

If you want, send me 1 pic, not too big, and I'll post it on one of my sites and place the link here.

Chris Gordon · April 14th, 2004, 04:42 AM

Here is an 11Mb mpeg of the green sunset:

http://www.angelfire.com/biz7/plasma...reensunset.mpg

***Right click on the link and select "Save Target As"... then open from your desktop.

Heath McKnight · April 14th, 2004, 07:58 AM

Chris,

Couldn't open it; could you maybe put up a jpeg of one of the frames and provide a link?

Thanks,

heath

David Kennett · April 14th, 2004, 08:52 AM

Chris

I've shot MANY sunsets with HD10 and never saw anything like that. Extreme highlights cause "star filter" effect, and EXTREME highlights cause a green line down from the highlight. I would think the sun that low would not cause that effect though. All my sunsets were shot with only a UV filter, MWB set to "sun", and exposure set to one or two notches below auto.

Hope this helps,

Paul Mogg · April 14th, 2004, 10:38 AM

You know, the renowned French film director Eric Rohmer, made a film about exactly this phenomenom, it's called "The Green Ray" and the premise is that just as the sun is setting, a green ray appears from the sun just before it sinks below the horizon, and that if you kiss a girl just at this moment, while it's happening, you will be in love!
Absolutely true...and maybe this is what you captured??

Have fun

Paul

Chris Gordon · April 14th, 2004, 12:52 PM

Here's the "green ring" in a jpeg file format.

http://www.angelfire.com/biz7/plasma...reensunset.jpg

Sten Newfield · April 14th, 2004, 01:09 PM

I don't think this is the Green Ray or Green Flash effect captured. The so called green flash occurs momentarily right after the tip of the sun has disappeared below the horizon. Maybe what was captured here was the JVC's hybrid complementary primary digital filter at work, mistakenly reading a certain wavelength as green.

Perhaps the same effect as reported here?

Betsy Moore · April 18th, 2004, 01:32 PM

Our HD-1 reads purple Christmas lights as green. I thought it was probably to do with that strange phenomenon you might have done as a kid on a regular TV--where if you shoot a green object with the camera biased toward green, then play it on tv and adjust the TV's hue to green the object turns pink, almost so green it's not green anymore, as if it's traveled so far on the color wheel it's reached the beginning. We're all getting a little poetic on this problem--kinda nice:)

April 14th, 2004, 03:23 AM	#1
Chris Gordon Regular Crew Join Date: Feb 2004 Location: Hollywood, CA Posts: 44	Mysterious Green Ring So I just got back from a ten day cruise around the Caribbean & Central America and I decided that this was the perfect voyage to put the HD1 to the test. The majority of the footage looked pretty good. (With the help of ND filters, a good polarizer, a soft con filter, gradients etc... etc...) Some of the whites looked a little blown out AND I had a few instances with chroma noise issues, but for the most part the footage was acceptable... EXCEPT... when I shot sunsets. For some strange reason, I got a green ring around EVERY sunset that I shot. Then I remembered a post a few months back with a film producer who noticed the same mysterious green halo around a candle shot in one of his films. I tried changing WB settings, changing filters - and nothing worked. Is this a shortcoming of the single chip design?? -Chris Gordon Promo Producer KABC-TV Los Angeles

April 14th, 2004, 07:58 AM	#6
Heath McKnight MPS Digital Studios Join Date: Apr 2003 Location: Palm Beach County, Florida Posts: 8,531	Chris, Couldn't open it; could you maybe put up a jpeg of one of the frames and provide a link? Thanks, heath __________________ My Final Cut Pro X blog

April 14th, 2004, 08:52 AM	#7
David Kennett Major Player Join Date: Jul 2003 Location: North Ridgeville, Ohio Posts: 407	Chris I've shot MANY sunsets with HD10 and never saw anything like that. Extreme highlights cause "star filter" effect, and EXTREME highlights cause a green line down from the highlight. I would think the sun that low would not cause that effect though. All my sunsets were shot with only a UV filter, MWB set to "sun", and exposure set to one or two notches below auto. Hope this helps, __________________ Dave

April 14th, 2004, 10:38 AM	#8
Paul Mogg Major Player Join Date: Apr 2003 Location: San Francisco CA Posts: 386	You know, the renowned French film director Eric Rohmer, made a film about exactly this phenomenom, it's called "The Green Ray" and the premise is that just as the sun is setting, a green ray appears from the sun just before it sinks below the horizon, and that if you kiss a girl just at this moment, while it's happening, you will be in love! Absolutely true...and maybe this is what you captured?? Have fun Paul __________________ Paul

April 14th, 2004, 12:52 PM	#9
Chris Gordon Regular Crew Join Date: Feb 2004 Location: Hollywood, CA Posts: 44	Green Sunset Here's the "green ring" in a jpeg file format. http://www.angelfire.com/biz7/plasma...reensunset.jpg

April 14th, 2004, 03:56 AM	#2
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	Could it be the sun's reflection from the filter?

April 14th, 2004, 04:02 AM	#3
Chris Gordon Regular Crew Join Date: Feb 2004 Location: Hollywood, CA Posts: 44	I shot it every which way you could imagine. One take was "clean" with no filters on the lens. I still got the same result. I'm trying to figure out a way to post a still shot from the footage so that you all can see what I'm talking about.

April 14th, 2004, 04:05 AM	#4
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	Thanks. If you want, send me 1 pic, not too big, and I'll post it on one of my sites and place the link here.

April 14th, 2004, 04:42 AM	#5
Chris Gordon Regular Crew Join Date: Feb 2004 Location: Hollywood, CA Posts: 44	Here is an 11Mb mpeg of the green sunset: http://www.angelfire.com/biz7/plasma...reensunset.mpg ***Right click on the link and select "Save Target As"... then open from your desktop.

April 14th, 2004, 01:09 PM	#10
Sten Newfield Regular Crew Join Date: Jan 2004 Location: San Diego, CA Posts: 36	I don't think this is the Green Ray or Green Flash effect captured. The so called green flash occurs momentarily right after the tip of the sun has disappeared below the horizon. Maybe what was captured here was the JVC's hybrid complementary primary digital filter at work, mistakenly reading a certain wavelength as green. Perhaps the same effect as reported here? __________________ -ztn

April 18th, 2004, 01:32 PM	#11
Betsy Moore Major Player Join Date: Mar 2003 Location: Los Angeles Posts: 444	Our HD-1 reads purple Christmas lights as green. I thought it was probably to do with that strange phenomenon you might have done as a kid on a regular TV--where if you shoot a green object with the camera biased toward green, then play it on tv and adjust the TV's hue to green the object turns pink, almost so green it's not green anymore, as if it's traveled so far on the color wheel it's reached the beginning. We're all getting a little poetic on this problem--kinda nice:)