Sensor issues

Bradford Holt · January 30th, 2011, 12:04 PM

I've run into this problem a couple of times when shooting. The first was when shooting a snowcat - the white lights showed up purple. I have no idea what causes it, but it seems to happen only when shooting directly into industrial lighting. Attached is a screenshot (not from video - this is a straight photo I took last weekend where the same error showed up).

In the photo I'm shooting with the 24-105 at an F4 - 1/30 - gain of 2500 (I think - going from memory here). As you can see several of the lights are purple instead of white. Even the reflection in the water is purple.

In the second photo, this is an absolutely new problem, and a bit of a disconcerting one because I've never seen it before. I was videoing the sunset from a boat, and this bizzarre spot showed up in the center of the sun. I was using the 24-105 and was using a vari-ND.

The reason I post these two pictures together is I'm wondering if they're related in anyway. Anyone ever experience anything like this or know what it might be? Thanks in advance.

Wayne Avanson · January 30th, 2011, 12:33 PM

I had this effect last year. Not in every flash of the lights, but in most of them

Jean-Philippe Archibald · January 30th, 2011, 01:13 PM

If I remember well, Canon released firmwares that fixes this kind of problem in the past. I could be wrong.

Jon Fairhurst · January 30th, 2011, 02:04 PM

I believe that the very first firmware update for the 5D2 dealt with the "black dots on highlights" issue. It should be a thing of the past.

Regarding purple and green fringes, that's usually a lens issue and could also be caused by the vari-ND.

Wayne Avanson · January 31st, 2011, 04:27 AM

Indeed it should Jon, and I got that update. However, this was shot about a year ago and clearly it isn't fixed. Funnily enough, I thought it was fixed, because some theatre work I did after the update was dot free.
But how could it come back?
Vey odd.

Jon Fordham · January 31st, 2011, 08:52 AM

I shot a major label music video last October with Firmware 2.0.7 with lights in the frame pointing at the lens for intentional lens flares at the request of the director, and I had black dots. We simply ignored it on the day and removed them in post. But we shouldn't have had to do this. Canon should fix this problem once and for all. If the sensor is hit with bright light that clips, it should simply go white. Period.

Wayne Avanson · February 1st, 2011, 03:51 PM

Do I remember rightly. Didn't the RED have a little red dot in the middle of highlights for a while? Did they fix that?

January 30th, 2011, 12:04 PM	#1
Bradford Holt New Boot Join Date: Feb 2009 Location: Los Angeles, CA Posts: 21	Sensor issues - Highlight errors I've run into this problem a couple of times when shooting. The first was when shooting a snowcat - the white lights showed up purple. I have no idea what causes it, but it seems to happen only when shooting directly into industrial lighting. Attached is a screenshot (not from video - this is a straight photo I took last weekend where the same error showed up). In the photo I'm shooting with the 24-105 at an F4 - 1/30 - gain of 2500 (I think - going from memory here). As you can see several of the lights are purple instead of white. Even the reflection in the water is purple. In the second photo, this is an absolutely new problem, and a bit of a disconcerting one because I've never seen it before. I was videoing the sunset from a boat, and this bizzarre spot showed up in the center of the sun. I was using the 24-105 and was using a vari-ND. The reason I post these two pictures together is I'm wondering if they're related in anyway. Anyone ever experience anything like this or know what it might be? Thanks in advance. Attached Thumbnails

January 30th, 2011, 12:33 PM	#2
Wayne Avanson Major Player Join Date: Feb 2008 Location: Lancashire UK Posts: 496	I had this effect last year. Not in every flash of the lights, but in most of them Attached Thumbnails __________________ Avey theactionhouse.com

January 30th, 2011, 01:13 PM	#3
Jean-Philippe Archibald Trustee Join Date: Sep 2003 Location: Saguenay, Québec, Canada Posts: 1,051	If I remember well, Canon released firmwares that fixes this kind of problem in the past. I could be wrong. __________________ Jean-Philippe Archibald http://www.jparchibald.com - http://www.vimeo.com/jparchib

January 30th, 2011, 02:04 PM	#4
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	I believe that the very first firmware update for the 5D2 dealt with the "black dots on highlights" issue. It should be a thing of the past. Regarding purple and green fringes, that's usually a lens issue and could also be caused by the vari-ND. __________________ Jon Fairhurst

January 31st, 2011, 04:27 AM	#5
Wayne Avanson Major Player Join Date: Feb 2008 Location: Lancashire UK Posts: 496	Indeed it should Jon, and I got that update. However, this was shot about a year ago and clearly it isn't fixed. Funnily enough, I thought it was fixed, because some theatre work I did after the update was dot free. But how could it come back? Vey odd. __________________ Avey theactionhouse.com

January 31st, 2011, 08:52 AM	#6
Jon Fordham Major Player Join Date: Sep 2003 Location: New York, NY Posts: 242	I shot a major label music video last October with Firmware 2.0.7 with lights in the frame pointing at the lens for intentional lens flares at the request of the director, and I had black dots. We simply ignored it on the day and removed them in post. But we shouldn't have had to do this. Canon should fix this problem once and for all. If the sensor is hit with bright light that clips, it should simply go white. Period. __________________ Jon Fordham Director of Photography www.jonfordham.com

February 1st, 2011, 03:51 PM	#7
Wayne Avanson Major Player Join Date: Feb 2008 Location: Lancashire UK Posts: 496	Do I remember rightly. Didn't the RED have a little red dot in the middle of highlights for a while? Did they fix that? __________________ Avey theactionhouse.com