Hi,

Had a shoot yesterday which involved an interview. A black chair and some background elements looked brown, dreaded IR!!

So are we any closer to knowing which filter is best?

True Cut 750 or the 486?

Many thanks,

Darren

Hello Darren,

The 486 is the filter recommended by Schneider.

I have one on my EX-1 & HPX-500 and do not see any green issues.

The HPX-500 needs it just as much as the EX-1 btw.

Hi Tim,

Interesting as some people report the issue of the green vignetting while others don't. I'm wondering wether it could be down to which firmware you have?

Is it right I have to get the slim version of the 486?

Wish I got the 486.
I ended up getting the RedRockMicro Hot Mirror (Redrock microFilters (http://www.redrockmicro.com/microFilters/index.html)) and it only cuts the IR a *tad*. Still very noticeable in certain situations.

This is what I read.
"It appears that the Sony EX cameras exhibit the same form of IR sensitivity that the Sony F35 and the Panavision Genesis do. Therefore the best filter for these cameras is not an IR Hot Mirror but instead a Tiffen IR ND non-Hot Mirror filter. This filter set was created for the F35 and Genesis. It is also less expensive than the Hot Mirror type filters such as the Formatts we sell for the RED.

Please note that different types of cameras and sensors require different type of filtration. The Formatts remain the recommended solution for the RED but the Tiffen non-Hot Mirror product is best for the EX1/EX3.

Art Adams over at ProvideoCoalition.com is doing an IR Filter Shoot Out to see how filters from three manufacturers work with the RED, F35 and EX Cameras."

Last I read the results Art were getting were not entirely valid. Some further work was in progress but I've not read anything since before NAB.

Schneider did have a new IR cut filter at NAB that Ryan showed me. It's an IR cut combined with a polariser. My understanding is the the addition of the polariser stops the green vignetting problem. Don't know anything more about it than that. Ryan did say he'd provide more information about it here but so far nothing.

Personally I'm quite happy just leaving a 486 on my EX1 however as I now have a .75 WA adaptor I'll need to rethink this.

Bob

I assume the IR + Pola has a 2 stop exposure loss?

Bob

I assume the IR + Pola has a 2 stop exposure loss?

Didn't think of that, yes, reading up elsewhere it seems a polarizer has a loss of around 2 stops. That kind of rules it out in many situations for me, darn.

I did tests with Art about a month or so ago. On the Ex-1 the only thing that really worked worth a Dxxx was the 486 which was great but vignettes green at wide angles.

We talked with tiffen and they are trying to make a dye based filter for Tungstun on the Ex, but haven't heard back form them yet. until then the 486 is the only game in town.

Rosco 4x5.650 (Panavision) TruColor IR Camera Filter was supposed to be reviewed. Has anyone received one? I know it works on RED ... will it work on EX1/3? The reason I ask is that the Rosco is clear ... not ND, not polarizer and not a hot mirror. It has Sharp cut-offs below 390nm and above 720nm to restore the balance of visible and invisible light reaching the camera sensors. This is what we need ... is it not?

From what I've read it's @ 680 to @ 700 where the EX is lacking.

From what I've read it's @ 680 to @ 700 where the EX is lacking.

Exactly - hence the question: anybody successul with the Schneider 680 ???

From what I've read it's @ 680 to @ 700 where the EX is lacking.

You are right on that David.

Exactly - hence the question: anybody successul with the Schneider 680 ???

The Tru-Cut 680 is the same filter as the 486. The only difference is the 680 is designed for matte box use (either 4x4 or 5.65x4) and the 486 is 77mm screw-in. Other than that, they are identical in construction and performance. (correct me if I'm wrong Ryan) I have used the 680 and it works exceedingly well at removing IR contamination, but it does cause the slight green vignetting at focal lengths wider than 15mm. The 750 will NOT work on the EX. I believe that has been covered extensively in other posts.

The IRNDs (by Tiffen) will have some effect on IR contamination, but cannot be used with any other ND because the amount of dye in the filter is based on the level of ND needed. Therefore, adding ND (without adding dye) will add visible IR contamination since there isn't enough dye present to counter the amount of IR contamination. What this means is, you cannot use your built-in NDs on the camera, and you cannot use any other NDs unless they contain the dye if you want to correct the IR issue. This can add up to a MUCH more expensive solution than the 680/486, depending on how much ND you need, because you would need several of these filters. (or, if you just buy one heavy ND, limits your exposure options dramatically)

I am curious about the new filter Ryan showed at NAB... this is the first I have heard of it. I wonder if using a polarizer along with the 680 would have the same effect as this new filter with it built-in? (ie, polarizer behind the 680?) Ryan? Any thoughts on this? This would offer more flexibility if shooting at a longer focal length than 15mm, or needed all the light you could get and didn't want to lose a couple stops to the pola.

I did a test with the rosco. it worked very well at getting rid of red IR in black cloth. BUT, it has similar green vignetting on W/A lenses. Both with the EX-3 & the Red.

My memory is getting fuzzy about what Art and I tested as he brought a bunch of filters. I thought he brought both the Rosco and the IR pola and that neither knocked my socks off on the EX. But i should check back with him.

I know that the 486 was extremely effective and it remained equally effective no matter how much standard ND you added.

Likewise I was unimpressed with the Tiffen IR ND's. They seemed pretty ineffective until we got up to massive amounts of ND. i.e the N21 looked reasonably effective but the N6 did nothing.

Be patient and cross your fingers.

Leonard,

Does Tiffen produce any IR cut filter without any ND built in? I'm not interested what happens when one adds further ND's. My problem is being encountered indoors under tungsten lights (when obviously I would be shooting in filter 1 and most of the time, almost a wide open apeture so as to film with available light). At present I'm using the 486, with excellent black rendition but I'm closing my eyes for the peripheral green tint.....!

Leonard,

Does Tiffen produce any IR cut filter without any ND built in? I'm not interested what happens when one adds further ND's. My problem is being encountered indoors under tungsten lights (when obviously I would be shooting in filter 1 and most of the time, almost a wide open apeture so as to film with available light). At present I'm using the 486, with excellent black rendition but I'm closing my eyes for the peripheral green tint.....!

Adding ND to the Tiffen ColorCore (IRND) filters that is NOT another IRND filter will allow more IR contamination to show in your image. As mentioned repeatedly in these forums, the Tiffen filters base the amount of dye needed to correct the contamination by the level of ND in the particular filter. You MUST use their IRNDs for ANY ND needed when using the IRNDs to correct for contamination. No other NDs can be used, not even the ones built into the camera. Stick with your 486, at the moment it's the best option we have for eliminating the contamination.

That said, I'm very curious about the possibility of using a polarizer in conjunction with the 486/680 to offset the green vignetting. When I get a chance, (which is not soon) I'll give this a try. If Schneider is playing with a combination of the two, it makes some sense (I hope) that this might work with a separate pola too.

Brian,
Tiffen is working on a dye filter for IR without ND. Results are promising but it is still in development. Cross your fingers as this would be what we want.

Derek,
In theory you are correct, however current Tiffen IRND's are just not very effective on the EX-1. Hopefully a better dye solution for tungstun will result in a better ND solution as well.

Just by chance I had a talks with these people today Optical Manufacturing (http://www.flo.com.au/Optical_Manufacturing.htm). Person I spoke with immediately understood our problem and does have a solution as they have developed a process for making dichroic filters without the vignetting issue by adjusting layer thickness over radius. Unfortunately the process is very slow, the design is difficult and the cost (probably an order of magnitude greater than a 486) would not make it a viable solution. My offer of an immediate order for 1,000 filters created no interest. My understanding is that their process has never been used commercially due to the cost. All that seems to remain of their work is a very interesting prototype in the showroom. Perhaps if some wealthy benefactor would like to kick in a couple of million in seed capital we could get them interested again.

Bob, I've wondered whether some kind of a rounded filter like the front element of a lens but without optical characteristics ( if that's possible) might work as well.

Bob, I've wondered whether some kind of a rounded filter like the front element of a lens but without optical characteristics ( if that's possible) might work as well.

I floated exactly that idea to the guy from Francis Lord!
The problem is the vacuum depositing process would not deposit an even layer of metal, it would get thinner towards the edge. Now that at first might seem like a good thing however balancing that and the change in angle of incidence might be a task and a half.

He did say that adding a polarizer in front of the dichroic is another solution but as we know you loose light.

I visit these people fairly regularly as we buy our Storm cases from them. I'll try to persue any and all ideas however I came away from the discussion with the feeling that any optical problem can be solved....if you're prepared to pay for it. It's not just the cost of manufacture. They need the best brains around to work on these problems and the few there are work in public funded research which does not sit too well with commercial ventures. These guys are sure serious, the specs on the mirrors they helped grind for the LIGO telescopes are mind boggling, around 1 atom thinkness tolerance.

I floated exactly that idea to the guy from Francis Lord!
The problem is the vacuum depositing process would not deposit an even layer of metal, it would get thinner towards the edge. Now that at first might seem like a good thing however balancing that and the change in angle of incidence might be a task and a half.

He did say that adding a polarizer in front of the dichroic is another solution but as we know you loose light.

I visit these people fairly regularly as we buy our Storm cases from them. I'll try to persue any and all ideas however I came away from the discussion with the feeling that any optical problem can be solved....if you're prepared to pay for it. It's not just the cost of manufacture. They need the best brains around to work on these problems and the few there are work in public funded research which does not sit too well with commercial ventures. These guys are sure serious, the specs on the mirrors they helped grind for the LIGO telescopes are mind boggling, around 1 atom thinkness tolerance.

Glen Davis over at Francis Lord optics did suggest, in a query I sent, that we talk to Dr David MacKenzie at the University of Sydney on this matter. I have no idea what that means but you are in Auz and may be better suited to contact the good professor to get a heads up.

Glen Davis over at Francis Lord optics did suggest, in a query I sent, that we talk to Dr David MacKenzie at the University of Sydney on this matter. I have no idea what that means but you are in Auz and may be better suited to contact the good professor to get a heads up.

Thanks Dean,
I'll try to follow this up for all of us.

Progress: ProVideo Coalition.com: Stunning Good Looks by Art Adams | Cinematography (http://provideocoalition.com/index.php/aadams/story/tiffen_tests_new_no_nd_ir_filter_for_ex1_ex3_f35/)

Progress: ProVideo Coalition.com: Stunning Good Looks by Art Adams | Cinematography (http://provideocoalition.com/index.php/aadams/story/tiffen_tests_new_no_nd_ir_filter_for_ex1_ex3_f35/)

The filter seems to cover the need. Of course, I'll be picking one up as soon as it's available. kuddos to Art for his work!!!

OK Art broke the news, in a very informative article. That's what i was referring to when I said be patient and cross your fingers. Art and I have been talking to Tiffen about trying to make, a dye based IR filter for Tungstun and the prototype looks very promising. This would be a great step forward for us.

Kudos also to Robert Orlando and his team at Tiffen.

I hope to get one to test soon as well.

Hopefully, getting this right will help them nail down the correct amount of green for effective IR ND filters on the EX-1 as well. I hope you don't end up needing different IR and IRND's for every camera.

Wouldn't it be nice if this thread could be retired at last.

The engineer in me says that we're going about this the wrong way. The correct approach should be to plot the spectral response of the EX cameras and at ND0, 1 & 2. From that we should know what the spectral transmission of the filter needs to be and any other issues we might have.
I could possibly, maybe get access to the needed light source but I'm totally at a loss as to how to use that to measure the response of the camera, would something as basic as a waveform monitor do?
How do we calibrate out white balance?

Gents, much learned from this discussion and tons of appreciation for the sharing. For myself, who is expecting his ex3 next week, and a non understander of the technical reasons why, I can only ask, where do I avail myself of the 486 filter in the UK?

Bob, I assume that's the kind of work going on at Tiffen.

Bob, I assume that's the kind of work going on at Tiffen.

I'd sure hope that's what they and others are doing too.
If that's what they are doing though surely they should be publishing the spectral transmission curves of their filters. Then you and Art and anyone else testing these filters has baseline data to work from, you know that from the published data it should work and all you're doing is validating the manufacturers claims in real world situations.

If you scroll down the following page
diglloyd: Spectral Transmission Graphs for B+W, Hoya, XNite, Baader, Kenko filters (http://diglloyd.com/diglloyd/free/CoastalOptics60f4/spectral.html)
you can compare the data between the 489 and 486 filters. You can see why the 489 is of no use with our problem. Compare the 486 plot against the Kenko DR-655 and you can see a filter that might solve the far red problem but introduce a problem with color rendition.
This is the sort of hard data we should be working from.

I raised my concerns about having an IR problem with another camera (SI-2K). I'd asked if we should be using ND filters with IR cut and was told no way, that would for certain affect color rendition on a camera designed to provide a wider gamut than rec 709. Hence my concerns here. We need to know not only that the problem is solved but also that we're not giving up anything or if that's inevitable what we are giving up.

When I spoke to them at first they hadn't really done testing on the EX-1 specifically and were surprised that the filters that were developed for the S35 didn't work the same on the EX. They told me they were asking Sony for an EX to test with.
I can't say whether they'll publish spectral response curves or not though they usually do. You'd probably have to get Sony to publish spectral curves for EX response.

I posted a very brief clip showing my Schneider/B&W 486 filter in action:

IR contamination of Sony EX1 on Vimeo (http://www.vimeo.com/4791723)

All of the black fabric objects in the shot (except for one) showed the IR problem. I also took the filter out in the bright sun today and used the same tripod bag to test for IR. The sun made the bag just as brown/maroon as it appeared here and the filter cleaned it up again. The tiny bit of green tint introduced by the filter can be corrected in post MUCH easier than the all those black objects turning brown, but I still think it sucks that we have to buy $300 filters to fix this problem.

I tried our True-cut 750 4x5.65 yesterday with our EX1 in bright sunlight shooting a black Underarmour "loosegear" shirt which is made of 100% polyester. I white balanced without the filter and with the filter just to see if there's any difference. Brown. I saw a reduction with the 750 but to such an infinitesimal amount that most eyes would unquestionably say there was no difference. I'll be contacting Schneider.

The green vignetting of the 486 is unacceptable to me. I often hand off footage to editors and it just won't pass the muster to make excuses about a vignetted color cast with all my footage. Only thought I have now is to find out in advance if there are synthetic fabrics involved in the shoot and try to avoid them. Has anyone tried to mitigate this with the EX1's matrix controls aka "color correction" targeted to the black? I can only imagine the time you might have shooting a fashion job for example and being unaware of this problem until the client sees the footage.

Thanks for sharing the video Dave.
It clearly shows how well the 486 filter works.

I agree with the green vignette issue so I'd avoid using my 486 filter with any wideangle shots, but I'm still not happy about it....obviously. Also, you're going to have problems making any blanket statements about which fabrics will give you IR problems. In my test footage (above), there was a mixture of woven fabrics and the t-shirts (and possibly the hat) were 100% cotton. The tripod and light bags appear to have more of a synthetic sheen like a polyesther material. The only thing in that shot that did NOT reflect IR back to the camera was the office chair fabric. There was no indication on the bottom of the chair as to what the fabric covering was made from. A quick check of their web site showed that it might be something called Olefin or it might be a 55/45 cotton/poly blend. It's a 10+ year old chair, so who knows.

Thanks for sharing the video Dave.
It clearly shows how well the 486 filter works.

Steven, the one thing I neglected to do was do another White Balance adjustment after mounting the filter just to negate the green shift. Maybe I'll repeat the test or somebody else can do it.

Good points Dave.

I skimmed over the possible upcoming Tiffen dye-based product. Personally I prefer Schneider filters over others when possible so I hope they come up with a solution, tested with EX. One problem I see with WB to cancel the green cast is the uneven pattern of a vignette. Obviously WB will take out a uniform level of green over the entire image so I'm wondering what results 486 users who WB with the filter on are getting at wide when there was more green around the edges than the center.

You're right, Max, and I'd probably avoid using it in extremly wide shots that had uniformly colored backgrounds. I know....it's a stupid way to have to work, but there you go. I think if you have a fairly complex or "busy" background, you might be able to hide the green effect. Frankly, I'm not going to use it unless I know that I have a LOT of black fabric subject matter in the shot but it sure seems like a waste of $300 to have it in the bag just waiting for those kinds of shots. I could have used that $300 for a lot of other stuff.

I hope to test the Tiffen prototype on Thursday.

Leonard, please let us know how the tiffen works out.

Shot some interviews the other day with a group of firefighters. They were all wearing black t-shirts and black caps, with their station logo on them. All the clothing came out brown/purple, while the logos looked true. This was a bummer because these guys know what it should look like. Since there is no definitive cure to date, and I'm not spending $200-$500 for a filter that only kinda fixes it, I went back to informal testing. I grabbed 5 black t-shirts, a black hat, some black jockey shorts and a black bag and shot them using various PP and no PP. All but the jockey shorts showed IR contamination! Lighting was overcast daylight, manual white balance. ND made no difference. What I found was that the BBC Film PP showed the least contamination (IR still there, but in a pinch it's better than nothing). You can find it on the forum.