Filter for IR contamination

Anthony McErlean · March 29th, 2009, 10:16 AM

Thanks for that link Daniel, well done. I can see it fixes the blacks and I can now understand why its best to use it only when needed. I did see the white wall just to the left of the chair (our left) turn a very light lime green and the out side shot (fence) I seen the filter darken the picture slightly. I thought I saw a hint of green in the sky shot.

From what I seen its definitely need for the blacks but to keep it off when not needed.

I'm just wondering how I would work this out when I video my weddings. Grooms can have black suits, brothers and sisters of brides and grooms in family photos can and do ware black and if it turned out a different colour in the DVD they would notice this right away.

A few weddings ago the bridesmaids wore black dresses and the brides mother wore black.
So how would you go about dealing with that.

I think theres something badly wrong when we have to fit filters to correct this.

Ed Kukla · March 29th, 2009, 10:37 AM

I understand that the 486 HAS to be the outside filter, no filters in front of the 486. So a screw on can be problematic if you want to add another filter like a polarizer.

I don't find any 4 X 4 486 filters. Any leads?

Derek Reich · March 29th, 2009, 11:06 AM

Quote:

Originally Posted by Ed Kukla

I understand that the 486 HAS to be the outside filter, no filters in front of the 486. So a screw on can be problematic if you want to add another filter like a polarizer.

I don't find any 4 X 4 486 filters. Any leads?

That's because in the 4x4 size, the 486 is called a 'Tru-Cut 650'
(don't ask me why)
I got one just the day before yesterday through Filmtools in CA. I don't know if they stock it, or had to order it in, but Ryan Avery (the Schneider rep) was very kind to arrange for delivery of the filter. He mentioned several different retailers you can get one through. I just like Filmtools for my past experience dealing with them, but Ryan mentioned you can also get one through Abel Cine, Alan Gordon Enterprises, or Express Video Supply.
I haven't had a chance to play with it yet, but am optimistic that it's the best choice at the moment, with the understanding that it does have some shortcomings which have already been addressed at length in this forum.

Piotr Wozniacki · March 29th, 2009, 11:27 AM

Quote:

Originally Posted by Derek Reich

That's because in the 4x4 size, the 486 is called a 'Tru-Cut 650'

Actually 680, isn't it Derek? If so, that would be for the 680 nm range that it's cutting at (unlike to 750 which is of the "Hot Mirror" type, and has proven to not be effective with the EX - or more generally, CineAlta - series of cameras).

BTW, do you happen to know whether its 4x5.65" version is also available?

Daniel Alexander · March 29th, 2009, 12:12 PM

Quote:

Originally Posted by Anthony McErlean

Thanks for that link Daniel, well done. I can see it fixes the blacks and I can now understand why its best to use it only when needed. I did see the white wall just to the left of the chair (our left) turn a very light lime green and the out side shot (fence) I seen the filter darken the picture slightly. I thought I saw a hint of green in the sky shot.

From what I seen its definitely need for the blacks but to keep it off when not needed.

I'm just wondering how I would work this out when I video my weddings. Grooms can have black suits, brothers and sisters of brides and grooms in family photos can and do ware black and if it turned out a different colour in the DVD they would notice this right away.

A few weddings ago the bridesmaids wore black dresses and the brides mother wore black.
So how would you go about dealing with that.

I think theres something badly wrong when we have to fit filters to correct this.

I agree that its wrong we have to fork out for a filter that is going to affect so many shooting applications, its just crazy. Although the filter does have a slight green tint if I were shooting weddings I would make the sacrifice and just keep it on, because I'd rather deal with a shifted white point rather than a black suit turn red. In post I can pretty easily get my white balance sorted so the green tint is gone (if it was even noticeable which is questionable) but unless i do several secondary colour passes i can't turn the reddish brown suits back to black again.

Dave Morrison · March 29th, 2009, 12:37 PM

Daniel, what was the exact part number or catalog number of the filter you were using? This was the screw-in version, correct?

Derek Reich · March 29th, 2009, 12:56 PM

Quote:

Originally Posted by Piotr Wozniacki

Actually 680, isn't it Derek? If so, that would be for the 680 nm range that it's cutting at (unlike to 750 which is of the "Hot Mirror" type, and has proven to not be effective with the EX - or more generally, CineAlta - series of cameras).

BTW, do you happen to know whether its 4x5.65" version is also available?

Yeah Piotr, you are correct. It is a Tru Cut 680.
Sorry for my brain-fart there.

Anthony McErlean · March 29th, 2009, 01:28 PM

Quote:

Originally Posted by Daniel Alexander

I would make the sacrifice and just keep it on, because I'd rather deal with a shifted white point rather than a black suit turn red. In post I can pretty easily get my white balance sorted so the green tint is gone.

Would that greenish tint be noticeable against church windows or a shaft of sunshine on a church wall for instance.

Quote:

Originally Posted by Daniel Alexander

... In post I can pretty easily get my white balance sorted so the green tint is gone.

So colour correction could sort out the greenish bits.

Perhaps this isn't as bad as I'm reading into it, I don't know. Just when coming from a camera were theres not bother like this, it makes you wonder.

David C. Williams · March 29th, 2009, 03:55 PM

The greenish tint reduces to nothing as you zoom in. The coating on the filter reflects different wavelengths at different angles, so full wide using the outer curve of the lens picks up light at a different angle. That's why you get a greenish vignette.

Daniel Alexander · March 29th, 2009, 04:30 PM

Heres a link to the exact filter to answer Dave's question B&W UV-IR Digital 77: Amazon.co.uk: Electronics & Photo.

Anthony I'm quite confident that you wouldn't have a problem with the green tint against any window or shaft of sunlight mainly because after white balancing with the filter already screwed on you can hardly tell the difference anyway, I mean from my tests I couldn't imagine the green cast being anywhere near strong enough to cause me a problem UNLESS i was filming against a white background at full wide (even then a short zoom in will solve that problem).

Yes colour correcting in post easily sorts this problem out and thank God it's as simple as using an eye dropper tool to tell your application what colour white is supposed to be and because I usually balance my pictures with a colour correcting wheel anyway I don't find myself having to do any extra work which is good. But i stress again that I doubt you'd even need to do this as in most cases it's only visible if you have pre-filter footage to compare it next to.

All in all i am not happy that I have to use a filter to correct something Sony failed to even mention initially but I am happy that despite it's drawbacks, I now have a solution to create videos that I want, looking how i want (even if it means an extra click or too in FCP to re-white balance).

Anthony McErlean · March 29th, 2009, 04:43 PM

Thanks Daniel, well, its good to know its not as bad as i first thought and if a slight zoom in from a wide cures it, thats good to know too. Glad the window thing isn't going to be a problem.

I received the filter from the supplier below on Saturday BTW

B+W 486 UV/IR MRC SH 77mm Ultraviolet / Infrared Cut Filter

Thanks again.

Michael B. McGee · March 30th, 2009, 01:25 PM

i haven't read all the threads but i've been looking for the Schneider Tru-Cut 680. the one that ProVideo Coalition recommended for the EX cameras. Ryan at Schneider said i can buy it at Film Tools in Burbank, CA. i believe he told me the filters are on back order. i think about 3 weeks out from purchasing.

Ed Kukla · March 31st, 2009, 03:34 PM

Tiffen Filters also make an IR filter. Seems that this one is made differently than the Schnieder and that you don't get the green cast with W/A lenses. In addition, I think you don't need to put the filter on the outside, before any other filters. Downside is that they only make them in square and rectangular.

Anybody using a Tiffen Hot Mirror??

David C. Williams · March 31st, 2009, 04:28 PM

It's the Tiffen IR ND filter, hot mirrors do nothing for the EX, it already has one built in.

As far as I know you can't get them without the ND as well. They use a dye in proportion to the ND component to block far red, and you get no vignette as it's not a dichroic.

Ed Kukla · March 31st, 2009, 05:03 PM

David
I was on the phone today with Tiffen. You can get the filter WITHOUT ND. It is somewhat confusing as they mostly make the IR WITH ND for Red cameras.

March 29th, 2009, 10:37 AM	#122
Ed Kukla Major Player Join Date: Mar 2008 Location: All over, USA Posts: 512	4 x 4 ? I understand that the 486 HAS to be the outside filter, no filters in front of the 486. So a screw on can be problematic if you want to add another filter like a polarizer. I don't find any 4 X 4 486 filters. Any leads?

March 29th, 2009, 12:37 PM	#126
Dave Morrison Major Player Join Date: May 2002 Location: West Central Florida Posts: 762	Daniel, what was the exact part number or catalog number of the filter you were using? This was the screw-in version, correct? __________________ EX1, Nikon D750 http://www.morrisonphotographics.com http://www.heritagefilm.com

March 29th, 2009, 03:55 PM	#129
David C. Williams Major Player Join Date: Jun 2008 Location: melb.vic.au Posts: 447	The greenish tint reduces to nothing as you zoom in. The coating on the filter reflects different wavelengths at different angles, so full wide using the outer curve of the lens picks up light at a different angle. That's why you get a greenish vignette. __________________ www.davidwilliams.com.au

March 31st, 2009, 03:34 PM	#133
Ed Kukla Major Player Join Date: Mar 2008 Location: All over, USA Posts: 512	Tiffen Hot Mirror? Tiffen Filters also make an IR filter. Seems that this one is made differently than the Schnieder and that you don't get the green cast with W/A lenses. In addition, I think you don't need to put the filter on the outside, before any other filters. Downside is that they only make them in square and rectangular. Anybody using a Tiffen Hot Mirror??

March 31st, 2009, 04:28 PM	#134
David C. Williams Major Player Join Date: Jun 2008 Location: melb.vic.au Posts: 447	It's the Tiffen IR ND filter, hot mirrors do nothing for the EX, it already has one built in. As far as I know you can't get them without the ND as well. They use a dye in proportion to the ND component to block far red, and you get no vignette as it's not a dichroic. __________________ www.davidwilliams.com.au

March 29th, 2009, 10:16 AM	#121
Anthony McErlean Trustee Join Date: Oct 2008 Location: Northern Ireland Posts: 1,082	Thanks for that link Daniel, well done. I can see it fixes the blacks and I can now understand why its best to use it only when needed. I did see the white wall just to the left of the chair (our left) turn a very light lime green and the out side shot (fence) I seen the filter darken the picture slightly. I thought I saw a hint of green in the sky shot. From what I seen its definitely need for the blacks but to keep it off when not needed. I'm just wondering how I would work this out when I video my weddings. Grooms can have black suits, brothers and sisters of brides and grooms in family photos can and do ware black and if it turned out a different colour in the DVD they would notice this right away. A few weddings ago the bridesmaids wore black dresses and the brides mother wore black. So how would you go about dealing with that. I think theres something badly wrong when we have to fit filters to correct this.

March 29th, 2009, 04:30 PM	#130
Daniel Alexander Major Player Join Date: Jul 2007 Location: West Midlands, UK Posts: 320	Heres a link to the exact filter to answer Dave's question B&W UV-IR Digital 77: Amazon.co.uk: Electronics & Photo. Anthony I'm quite confident that you wouldn't have a problem with the green tint against any window or shaft of sunlight mainly because after white balancing with the filter already screwed on you can hardly tell the difference anyway, I mean from my tests I couldn't imagine the green cast being anywhere near strong enough to cause me a problem UNLESS i was filming against a white background at full wide (even then a short zoom in will solve that problem). Yes colour correcting in post easily sorts this problem out and thank God it's as simple as using an eye dropper tool to tell your application what colour white is supposed to be and because I usually balance my pictures with a colour correcting wheel anyway I don't find myself having to do any extra work which is good. But i stress again that I doubt you'd even need to do this as in most cases it's only visible if you have pre-filter footage to compare it next to. All in all i am not happy that I have to use a filter to correct something Sony failed to even mention initially but I am happy that despite it's drawbacks, I now have a solution to create videos that I want, looking how i want (even if it means an extra click or too in FCP to re-white balance).

March 29th, 2009, 04:43 PM	#131
Anthony McErlean Trustee Join Date: Oct 2008 Location: Northern Ireland Posts: 1,082	Thanks Daniel, well, its good to know its not as bad as i first thought and if a slight zoom in from a wide cures it, thats good to know too. Glad the window thing isn't going to be a problem. I received the filter from the supplier below on Saturday BTW B+W 486 UV/IR MRC SH 77mm Ultraviolet / Infrared Cut Filter Thanks again.

March 30th, 2009, 01:25 PM	#132
Michael B. McGee Major Player Join Date: Nov 2008 Location: Santa Monica, CA Posts: 318	i haven't read all the threads but i've been looking for the Schneider Tru-Cut 680. the one that ProVideo Coalition recommended for the EX cameras. Ryan at Schneider said i can buy it at Film Tools in Burbank, CA. i believe he told me the filters are on back order. i think about 3 weeks out from purchasing.

March 31st, 2009, 05:03 PM	#135
Ed Kukla Major Player Join Date: Mar 2008 Location: All over, USA Posts: 512	David I was on the phone today with Tiffen. You can get the filter WITHOUT ND. It is somewhat confusing as they mostly make the IR WITH ND for Red cameras.