EX3 and ir contamination at DVinfo.net

Les Nagy · October 3rd, 2008, 09:58 AM

After reading this thread: http://www.dvinfo.net/conf/sony-xdca...d-problem.html and a couple of others it appears that this problem has not gone away. I have tried the B+W 486 filter and it works great except for very intrusive green vignetting at any focal length below 25mm. The green vignetting is as bad as the ir problem, so the filter goes back. I have a Tru-Cut filter coming from Schneider Optics and hope that will be a better solution for the short term.

I am very perplexed about the decision of the Sony engineers to use such a low cutoff for IR in their filtering. I can't see any benefit that could outweigh proper colour representation. Has anyone had any success with their complaints to Sony about this issue?

Barry J. Anwender · October 3rd, 2008, 10:13 AM

Quote:

Originally Posted by Les Nagy

I have a Tru-Cut filter coming from Schneider Optics and hope that will be a better solution for the short term.

Les, is the Schneider True-Cut IR filter round with 77mm threads for the EX1/3? I still cannot find this IR filter on the Schneider web site or anywhere else. Thanks!

Les Nagy · October 3rd, 2008, 10:20 AM

Quote:

Originally Posted by Barry J. Anwender

Les, is the Schneider True-Cut IR filter round with 77mm threads for the EX1/3? I still cannot find this IR filter on the Schneider web site or anywhere else. Thanks!

Schneider is just now producing the 77mm Tru-Cut. No one in Canada is carrying it or has it on order yet. Contact Schneider Optics directly.

Barry J. Anwender · October 3rd, 2008, 11:35 AM

Quote:

Originally Posted by Les Nagy

Schneider is just now producing the 77mm Tru-Cut. No one in Canada is carrying it or has it on order yet. Contact Schneider Optics directly.

Thanks Les and Cheers:-)

Alister Chapman · October 3rd, 2008, 01:05 PM

I think the very fact that so many people have tried to use add on filters without success, or with more issues than they started with shows why the camera is the way it is. It is extremely difficult to produce an aggressive IR cut filter that doesn't compromise the rest of the spectrum. This is not a problem unique to the EX. Almost all cameras that use ND filter will suffer from this as most ND filters don't attenuate IR as much as the visible spectrum.

Les Nagy · October 3rd, 2008, 01:26 PM

Quote:

Originally Posted by Alister Chapman

I think the very fact that so many people have tried to use add on filters without success, or with more issues than they started with shows why the camera is the way it is. It is extremely difficult to produce an aggressive IR cut filter that doesn't compromise the rest of the spectrum. This is not a problem unique to the EX. Almost all cameras that use ND filter will suffer from this as most ND filters don't attenuate IR as much as the visible spectrum.

I would agree Alister if it weren't a fact that CMOS DSLRs do not suffer the same fate and that most other video cameras do not have this issue. As a matter of fact, there are companies who's specialty is to modify some DSLRs to put a weaker IR filter in place so as to get the "problem" we are having with the EX series. I sincerely believe that the Sony engineers made the wrong decision as to what compromises to make.

Alister Chapman · October 3rd, 2008, 01:35 PM

DSLR's don't have integral ND filters and almost all CMOS video cameras and many CCD cameras that have ND filters DO suffer from this same problem, its just that very few of these cameras are being used by professionals that notice things like black cloths under tungsten light having a red hue.

Les Nagy · October 3rd, 2008, 11:53 PM

A quick comparison test using a halogen lamp, my Canon 40D, my Canon XL2, and my EX3:

1. I took a couple of shots of my camera bag at 1/60 with and without a NDx8 filter with my 40D. White balance set for 2800K. Naked shot had a slight hint of not quite black to the bag. There is a strap on the bag that looks black no matter what and it was hard to tell the difference naked. With the NDx8 the slightest of a dark purplish hue showed up on the bag and it was more apparent that it was not the same colour of the strap.

2. Set the white balance on my XL2 to incandescent setting, 30P, 1/60 shutter. All ND settings look very close with the absolute appearance being between the two shots on the 40D.

3. Ex3..... 2800K, 30P with 1/60 shutter. All settings of the ND filter make the bag look medium purple and the strap is jet black.

So while I agree that IR contamination is there in the other cameras to a very small extent and my absolute statement of "does not suffer from" is wrong, I still contend that Sony got it way wrong or my camera is defective. Judging by the results shown here:
ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews
compared to my results, I would have to say that mine is not defective. I get the same amount of black IR contamination. The difference between my 40D shot with an NDx8 and the EX3 without any ND engaged is as dramatic as shown in the filter comparison shots.

And yes I would have noticed that extreme a problem in my other cameras right away. It simply is not there with them. (Edit: I will have to eat these words in my next post)

This leads me to the only conclusion that I can come to with my data. Sony got it wrong.

Les Nagy · October 4th, 2008, 12:55 AM

I did some more careful testing with my XL2. I admit I had not seen the black problem as anything noticeable before. Upon finer examination and more playing I see that the XL2 does suffer from this problem, but not nearly to the extent that the EX3 does. I did not see any problems with it before probably because it was below a certain threshold that it didn't stick out like a sore thumb. With the EX3 some blacks just scream out the wrong colour.

If I had to qualify the difference in crude terms, I would say the EX3 is three times worse than the XL2 for this IR problem. I would still like to correct what I see as a wrong choice on what to compromise by Sony's engineers.

Thanks for making me take a closer look Alister.

October 3rd, 2008, 09:58 AM	#1
Les Nagy Major Player Join Date: May 2006 Location: A Canadian in Canada, and sometimes Chile Posts: 265	EX3 and ir contamination After reading this thread: http://www.dvinfo.net/conf/sony-xdca...d-problem.html and a couple of others it appears that this problem has not gone away. I have tried the B+W 486 filter and it works great except for very intrusive green vignetting at any focal length below 25mm. The green vignetting is as bad as the ir problem, so the filter goes back. I have a Tru-Cut filter coming from Schneider Optics and hope that will be a better solution for the short term. I am very perplexed about the decision of the Sony engineers to use such a low cutoff for IR in their filtering. I can't see any benefit that could outweigh proper colour representation. Has anyone had any success with their complaints to Sony about this issue?

October 3rd, 2008, 01:05 PM	#5
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	I think the very fact that so many people have tried to use add on filters without success, or with more issues than they started with shows why the camera is the way it is. It is extremely difficult to produce an aggressive IR cut filter that doesn't compromise the rest of the spectrum. This is not a problem unique to the EX. Almost all cameras that use ND filter will suffer from this as most ND filters don't attenuate IR as much as the visible spectrum. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

October 3rd, 2008, 01:35 PM	#7
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	DSLR's don't have integral ND filters and almost all CMOS video cameras and many CCD cameras that have ND filters DO suffer from this same problem, its just that very few of these cameras are being used by professionals that notice things like black cloths under tungsten light having a red hue. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

October 3rd, 2008, 11:53 PM	#8
Les Nagy Major Player Join Date: May 2006 Location: A Canadian in Canada, and sometimes Chile Posts: 265	A quick comparison test using a halogen lamp, my Canon 40D, my Canon XL2, and my EX3: 1. I took a couple of shots of my camera bag at 1/60 with and without a NDx8 filter with my 40D. White balance set for 2800K. Naked shot had a slight hint of not quite black to the bag. There is a strap on the bag that looks black no matter what and it was hard to tell the difference naked. With the NDx8 the slightest of a dark purplish hue showed up on the bag and it was more apparent that it was not the same colour of the strap. 2. Set the white balance on my XL2 to incandescent setting, 30P, 1/60 shutter. All ND settings look very close with the absolute appearance being between the two shots on the 40D. 3. Ex3..... 2800K, 30P with 1/60 shutter. All settings of the ND filter make the bag look medium purple and the strap is jet black. So while I agree that IR contamination is there in the other cameras to a very small extent and my absolute statement of "does not suffer from" is wrong, I still contend that Sony got it way wrong or my camera is defective. Judging by the results shown here: ProVideo Coalition.com: Camera Log by Adam Wilt \| Founder \| Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews compared to my results, I would have to say that mine is not defective. I get the same amount of black IR contamination. The difference between my 40D shot with an NDx8 and the EX3 without any ND engaged is as dramatic as shown in the filter comparison shots. And yes I would have noticed that extreme a problem in my other cameras right away. It simply is not there with them. (Edit: I will have to eat these words in my next post) This leads me to the only conclusion that I can come to with my data. Sony got it wrong. Last edited by Les Nagy; October 4th, 2008 at 12:56 AM.

October 4th, 2008, 12:55 AM	#9
Les Nagy Major Player Join Date: May 2006 Location: A Canadian in Canada, and sometimes Chile Posts: 265	I did some more careful testing with my XL2. I admit I had not seen the black problem as anything noticeable before. Upon finer examination and more playing I see that the XL2 does suffer from this problem, but not nearly to the extent that the EX3 does. I did not see any problems with it before probably because it was below a certain threshold that it didn't stick out like a sore thumb. With the EX3 some blacks just scream out the wrong colour. If I had to qualify the difference in crude terms, I would say the EX3 is three times worse than the XL2 for this IR problem. I would still like to correct what I see as a wrong choice on what to compromise by Sony's engineers. Thanks for making me take a closer look Alister.