EX1 infrared contamination: myth or reality? at DVinfo.net

Alex Raskin · October 12th, 2008, 04:17 PM

I have tested a B+W IR filter 486 with EX1, and could not see any difference in the image with vs. without the filter.

What practical situations lead to IR contamination? (screen shots illustrating IR filter saving the day would be most helpful...)

Piotr Wozniacki · October 12th, 2008, 04:36 PM

Please see my post in the Red Problem thread:

http://www.dvinfo.net/conf/862316-post113.html

Alex Raskin · October 12th, 2008, 05:16 PM

Piotr, would you be so kind as to re-state:

1. under what circumstances does the IR problem occur
2. what are advantages/disadvantages of using filter
3. any alternative solutions?

(The thread you referred to is huge, I'd really appreciate your digest...)

In my own tests:

1. I actually have not seen the problem yet. I'm shooting under fluorescent and LED lights, or natural sunlight, mainly.
2. 486 filter made everything greenish, which looked bad to me
3. ?

Alex Raskin · October 12th, 2008, 06:58 PM

Found this:

ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews

Dramatic example of EX1 rendering black shirt as brown; and 486 filter fixing the problem.

So all the reading I've done so far points out to the answer: "IR contamination - it depends... Have 486 filter handy just in case."

Is that a consensus?

Piotr Wozniacki · October 13th, 2008, 01:25 AM

Alex,

Yes, Adam Wilt's description of the problem is accurate. I'd add some points from my experience:

- the problems is most pronounced in tungsten light, and with clothes, fabrics etc. of certain colours (mainly black or dark blue)

- using the 486 filter is only recommended as the first optical element as it reflects IR, hence it's no good to be put between the camera lens and a 35mm adapter for example. Also, at the widest lens setting, the ugly green cast is visible at the image extremities (especially left and right edge)

- the 489 filter is supposed to absorb IR, so it doesn't have the limitations of the 486; it also produces the side effects though

- Schneider Optics claim their 750 nm filters do not produce the green cast; I haven't tried them yet

- Is the colour change a real problem? Well, certainly when somebody notices the colour infidelity, it's a rather embarrassing situation for a pro CineAlta camera owner / operator... Also, inter-cutting between the EX and other cameras is extremely difficult if not impossible with material shot in tungsten light.

Alex Raskin · October 13th, 2008, 05:23 AM

thanks Piotr...

I've read the entire thread you have referred me to, and it looks like True-Cut IR 750 is the ticket... do you know where to buy it in the US in 77mm version? (I don't think I'm ready for the matte box/4x4 at this point...)

Piotr Wozniacki · October 13th, 2008, 06:36 AM

Have no idea, Alex - but haven't looked for it, either. I have a microMatteBox on order, so I will be buying the 4x5.65" version some day (the 4x4" are reported to cause vignetting on the EX1).

Alex Raskin · October 13th, 2008, 06:45 AM

Surely you are not buying RR matte box just to hold the IR filter? What other filters are you planning on using with this cam?

I own a quality circular polarizer that is absolutely necessary with surface reflections and sky shots; and I was planning to get a IR filter now. Both screw-on type.

Piotr Wozniacki · October 13th, 2008, 06:50 AM

Along the matte box, I'm buying a set of 4x5.65" filters from RedrockMicro: the polarizer, ND, and grad ND. I think I will be using them quite often; also the matte box seems rather essential with my SLR lenses I use with Letus.

Jay Gladwell · October 13th, 2008, 07:24 AM

Quote:

Originally Posted by Alex Raskin

thanks Piotr...

I've read the entire thread you have referred me to, and it looks like True-Cut IR 750 is the ticket... do you know where to buy it in the US in 77mm version? (I don't think I'm ready for the matte box/4x4 at this point...)

Doesn't appear to be available in a circular 77mm version, which is very unfortunate.

Alex Raskin · October 13th, 2008, 07:33 AM

SLR w Letus: I mostly use the marvelous Zeiss 100mm macro, which has its own hood - so no matte box needed...

IR filter: I guess I'll stay with the 486 as a working option for now. At $167, it seems like a reasonable solution, comparing to $1,000 - $2,000 for matte box+filter... especially since the problem is relatively rare...

There's also a slim version of the 486 filter, which fits under EX1's stock lens shade.

George Kroonder · October 13th, 2008, 09:33 AM

Schneider Optics is planning a 77mm version of the True Cut IR 750; if it is not out yet it can't be long.

Try one of their resellers, like Abel Cine or B&H. You could even try PM-ing Ryan Avery of Schneider Optics for an update if you don't get anywhere with the resellers.

George/

Alex Raskin · October 13th, 2008, 09:40 AM

George, I did email Ryan from this forum's contact form, no response yet.

George Kroonder · October 13th, 2008, 09:45 AM

Well, he's pretty active on the forum but that's not to say he hasn't got other matters to attend to. I'm sure he'll get back to you "eventually".

In the mean time, give Abel (or preferred supplier) a call and ask them for a projected delivery date. They may even already have a pre-order list.

George/

Ned Soltz · October 13th, 2008, 09:51 AM

The IR issue is real.

I have been working with an testing the IR 750 for a couple of months. It makes a difference. I'll be featuring it in some upcoming writing and also will speaking about it next month in a session at an upcoming event in LA.

The 486 will give you a greenish cast.

Go with the 750

October 12th, 2008, 04:17 PM	#1
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	EX1 infrared contamination: myth or reality? I have tested a B+W IR filter 486 with EX1, and could not see any difference in the image with vs. without the filter. What practical situations lead to IR contamination? (screen shots illustrating IR filter saving the day would be most helpful...)

October 12th, 2008, 04:36 PM	#2
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Please see my post in the Red Problem thread: http://www.dvinfo.net/conf/862316-post113.html __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

October 13th, 2008, 01:25 AM	#5
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Alex, Yes, Adam Wilt's description of the problem is accurate. I'd add some points from my experience: - the problems is most pronounced in tungsten light, and with clothes, fabrics etc. of certain colours (mainly black or dark blue) - using the 486 filter is only recommended as the first optical element as it reflects IR, hence it's no good to be put between the camera lens and a 35mm adapter for example. Also, at the widest lens setting, the ugly green cast is visible at the image extremities (especially left and right edge) - the 489 filter is supposed to absorb IR, so it doesn't have the limitations of the 486; it also produces the side effects though - Schneider Optics claim their 750 nm filters do not produce the green cast; I haven't tried them yet - Is the colour change a real problem? Well, certainly when somebody notices the colour infidelity, it's a rather embarrassing situation for a pro CineAlta camera owner / operator... Also, inter-cutting between the EX and other cameras is extremely difficult if not impossible with material shot in tungsten light. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

October 13th, 2008, 06:36 AM	#7
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Have no idea, Alex - but haven't looked for it, either. I have a microMatteBox on order, so I will be buying the 4x5.65" version some day (the 4x4" are reported to cause vignetting on the EX1). __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

October 13th, 2008, 06:50 AM	#9
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Along the matte box, I'm buying a set of 4x5.65" filters from RedrockMicro: the polarizer, ND, and grad ND. I think I will be using them quite often; also the matte box seems rather essential with my SLR lenses I use with Letus. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

October 12th, 2008, 05:16 PM	#3
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	Piotr, would you be so kind as to re-state: 1. under what circumstances does the IR problem occur 2. what are advantages/disadvantages of using filter 3. any alternative solutions? (The thread you referred to is huge, I'd really appreciate your digest...) In my own tests: 1. I actually have not seen the problem yet. I'm shooting under fluorescent and LED lights, or natural sunlight, mainly. 2. 486 filter made everything greenish, which looked bad to me 3. ?

October 12th, 2008, 06:58 PM	#4
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	Found this: ProVideo Coalition.com: Camera Log by Adam Wilt \| Founder \| Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews Dramatic example of EX1 rendering black shirt as brown; and 486 filter fixing the problem. So all the reading I've done so far points out to the answer: "IR contamination - it depends... Have 486 filter handy just in case." Is that a consensus?

October 13th, 2008, 05:23 AM	#6
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	thanks Piotr... I've read the entire thread you have referred me to, and it looks like True-Cut IR 750 is the ticket... do you know where to buy it in the US in 77mm version? (I don't think I'm ready for the matte box/4x4 at this point...)

October 13th, 2008, 06:45 AM	#8
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	Surely you are not buying RR matte box just to hold the IR filter? What other filters are you planning on using with this cam? I own a quality circular polarizer that is absolutely necessary with surface reflections and sky shots; and I was planning to get a IR filter now. Both screw-on type.

October 13th, 2008, 07:33 AM	#11
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	SLR w Letus: I mostly use the marvelous Zeiss 100mm macro, which has its own hood - so no matte box needed... IR filter: I guess I'll stay with the 486 as a working option for now. At $167, it seems like a reasonable solution, comparing to $1,000 - $2,000 for matte box+filter... especially since the problem is relatively rare... There's also a slim version of the 486 filter, which fits under EX1's stock lens shade.

October 13th, 2008, 09:33 AM	#12
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	Schneider Optics is planning a 77mm version of the True Cut IR 750; if it is not out yet it can't be long. Try one of their resellers, like Abel Cine or B&H. You could even try PM-ing Ryan Avery of Schneider Optics for an update if you don't get anywhere with the resellers. George/

October 13th, 2008, 09:40 AM	#13
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	George, I did email Ryan from this forum's contact form, no response yet.

October 13th, 2008, 09:45 AM	#14
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	Well, he's pretty active on the forum but that's not to say he hasn't got other matters to attend to. I'm sure he'll get back to you "eventually". In the mean time, give Abel (or preferred supplier) a call and ask them for a projected delivery date. They may even already have a pre-order list. George/

October 13th, 2008, 09:51 AM	#15
Ned Soltz Major Player Join Date: May 2006 Location: Teaneck, NJ Posts: 659	The IR issue is real. I have been working with an testing the IR 750 for a couple of months. It makes a difference. I'll be featuring it in some upcoming writing and also will speaking about it next month in a session at an upcoming event in LA. The 486 will give you a greenish cast. Go with the 750