DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Sony XDCAM EX Pro Handhelds (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/)
-   -   EX1 infrared contamination: myth or reality? (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/135677-ex1-infrared-contamination-myth-reality.html)

Alex Raskin October 12th, 2008 04:17 PM

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...)

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 (Post 950536)
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


All times are GMT -6. The time now is 10:41 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network