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...)

Please see my post in the Red Problem thread:

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

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. ?

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?

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.

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...)

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).

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.

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.

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

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.

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/

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

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/

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

Ned, is the IR 750 available in 77mm for the EX1?

Also, no green issues?

Any other issues?

Cost?

Thanks

Check it out

Introducing True-Cut 750 IR Filter - Schneider Optics

$295 for the 4x4. No pricing listed yet for 77mm so I suspect they are still making those up. I do know that they plan to offer a 77 mm and I will buy one for my EX-3 as soon as they ship. Can't always shoot with the mattebox.

Important to note that the IR 750 must be the top first filter in your stack-- light must hit the IR 750 first and then stack other filters beneath it.

Ned Soltz

Ned, thanks for the info.

So 750 does *not* have green cast?

I assume yours is 4x4, not 77mm? (you beat me to it, I see the answer to 77mm above.)

After a month of going back and forth with Ryan/Schneider Optics, and 2 dealers, the Schneider's 750nm 77mm filter is still unavailable for purchase.

Meanwhile, I did run into some very severe cases of IR contamination, so hell yeah, the issue is real!

Both under the sunlight and fluos. Certain black fabrics really start looking dirty brown. Very ugly. Also saw this with female hair. (oh behave!)

The 486 filter fixes the issue.

I'm keeping my 486 filter screwed to EX1's lens all the time presently. It fits under the sunshade of EX1.

Just white balance with 486 on, and voila.

Hi Alex,

You have the slim version, any reason why?

Do you think the regular version of the 486 would fit under the EX1 sunshade?

Also, what is the widest you can go without getting the green cast on the side of your shots?

Thanks,

Rob

I'm not Alex, but can tell you from my experience that:

- the double-threaded 486 filter does fit under the lens hood
- the widest zoom with no green tint is around Z15 (in the 00 - 99 scale)

Thanks so much Piotr,

Z15 seems reasonable, I will go with the 486 since the True-cut 750 has not proven itself yet.

I have been waiting to long for this now. I have a 52mm 486 for my Letus and it does the job now I just need to find a double threaded 77mm 486!

Thanks again!

Not recommended. Since 486 reflects light, you cannot safely put anything in front of it.

So 486 must be the very first optical element, which makes front thread on it pointless IMHO.

However such version does exist, is 25% cheaper, and is sold by B&H or here.

Thanks Alex,

I understand, at least it is cheaper!

B&H is out of stock!

I've had the B&W Slim 486 on my EX1 for ages now. The only time I've taken the 486 off the camera was when it went back to Sony. I went with the slim as the normal filter seemed to make it a very tight fit for the lens hood. All our EX1 and 3s have been fitted with the same filter. The green vignetting no one has so far noticed and if it did become a problem it would be relatively easy to grade out. The magenta shift in some black fabrics borders on the impossible to grade out.

My understanding from reading numerous posts is that the 486 is the only filter that will effectively remove enough IR to completely avoid the problem. I might be wrong here but some seem to have been returning the 750 as it just didn't cut enough IR.

We've also purchased a number of expensive 'hot glass' ND filters as another way around this problem. The idea is to bypass the incamera ND filters entirely. However these filters do introduce another problem. From the front they're a very large mirror so reflections back towards the talent could become another issue to wrangle. For the money and ease of use the 486 still seems to be the best solution.

B&H just received some of the regular 486 77mm today!

Having no better options, I bought one! Not that I need it everyday, but I do need it for specific shoots, so the regular 486 will be perfect for my needs.

Thanks to all for your input,

much appreciated!

Is there an in-camera hardware or firmware remedy for the IR problem? Or are EX-1 users stuck with having to use an add-on filter for the life of the camera?

I've asked this in a couple of threads and no one answers!

Bob: the only remedy at this point is to limit the amount of IR *before* it hits the camera lens/sensor.

Just a couple of things I've gone through with ex1 IR contamination:

-It is a serious reality. Piotr is right, it is most prominent under tungsten on certain black fabrics, although lately I've found certain blue polyesters turning purple.

-Sony support doesn't seem to know (or care too much). I've spoken to several people about it at Sony support who respond with, "That's interesting, we'll have to ask the engineers".

-The 486 has been working for me very well behind my Letus Extreme adapter. Many people will tell you not to do this, and they may be right, but it is working for me. I have yet to see the true cut 750 filter yet, however I will be ordering a 4x5.65 once they become available.

-As mentioned in a previous post the green/cyan cast from the 486 that is found on the wide end with the 486 is actually pretty easy to remove in post compared to the alternative. At this point I have a preset secondary in Color that is basically a magenta adjustment with an inverted circular vignette.

-I have noticed this on other cameras, namely the Panasonic HPX-3000, and some F-23's were reported to have it until the IR filter was replaced. I'm wondering if that is a possible fix for the EX3, where the IR filter is more accessible.

-Sean

Sean, supposedly 750 is available for matte box placement here.

Also, Redrock Micro sell their own 4x5.65 750 nm IR filter:

microFilter IR Cut (Hot Mirror) 4x5.65"

Piotr, surely RedRock does not manufacture filters - do you know which brand do they re-purpose?

Have no idea (and don't think they would say), but Brian Valente, who's been giving me excellent support with my other orders with Redrock Micro, says they've learned a lesson from the competitor's attempts, and that theirs is better...

Would it stop you from purchasing the camera again?

Let me throw my 2 cents in here. My answer is no. The results from this camera are incredible when it is used properly.


I have purchased, returned, and re-purchased the B+W 486. The reason it wen back is because of the green vignetting. The reason I got it back was it worked otherwise.

I tried the Schneider Optics 750 True-cut, but it was useless, completely, on my camera. I provided proof in this thread:
http://www.dvinfo.net/conf/sony-xdca...aste-time.html
But people have said it worked for them yet I have seen no results from their use.

Until there is a better camera for the price I would buy the EX1/3 and know that it has its limitations like anything else does.

Alex, that link was for a 4x4 size. For the wide lenses on my adapter I need to use 4x5.65 or larger.

Bob, it would not stop me from purchasing this camera, however it is something to be aware of and you should be prepared to purchase filtration to deal with it. As I mentioned, I've seen the same phenomenon on an HPX3000, a camera that retails for 5 times the price of an ex1.

-Sean

No, I would buy EX1 camera again in a heartbeat really.

Just add this 486 filter (some say this one fits too), and you're good to go.

Additional expense to the camera cost: $150 - $200 depending on filter variant. Not pleasant, but yet not significant enough to stop from buying the cam. Hey, look at it this way: you have to buy many other accessories anyway... filter is just one of them. And, if you go the matte box route - fohgettabaoutit... money will start flying outta window in droves, so 77mm filter seems super cheap on comparison :)