It took me a long time before I noticed it.
That's always the problem in this game, deciding what matters and what doesn't.
Looking at a couple of screenshots that Piotr supplied I can see it quite clearly however I believe the camera was not WB after fitting the filter so the whole frame does have a bit of green caste to start with, it gets worse towards the edges for sure. One reason it's not been so obvious to me is the filter is always on my camera, as are all the other ones in our fleet so the cameras are always being WB'ed with the filter on.
So again the question is not is it there, the question is does it matter. I'd suggest it doesn't as the eye is not naturally drawn to it. Maybe it'd be different if the subject was up against a white wall but such shots are rare. On the other hand people wearing black sitting large in the middle of the frame are very common. The visual effect of the 'IR' problem does seem very distracting to the average normal viewer as there's nothing naturally like it. On the other hand a bit of fall off or caste towards the edge of a wide shot mimics what is sometimes seen in the natural world.

Well said - I fully agree with this reasoning. However on the other hand I remember the fuss that was kicked up on the very small vignetting that the early EX1's had and yet now we are creating a much larger and coloured vignetting.

Whate balance idea...
 

I'm sure everyone's white balanced through 1/8 or 1/4 CTB to warm up their subjects. I used to do this and sometimes I would also add 1/8 green, can't remember the exact gel. I started doing this when I would have to shoot with existing fluorescent lights, but then I came to think a little less green was good for skin tones much of the time.

What occors to me is that perhaps a gel or combination of gels the same color as the fringing, or as close as possible, could be used during the white balance.

The result would be a neutral color balance where the vignetting would have been, and a bit less green/cyan in the center where the subject is. This might look nice, or at least nicer than a bias in portions of the picture toward the green side.

Tip McPartland

Generally outdoors I do not use any additional IR filtering (while Bob uses it as default), but it isn't true to say that the IR problem isn't present under 5600K lighting. Attached are two recorded in sunlight (white balanced internal camera ND filters) and the black artificial fibre is recorded black only with the BW486 filter.


Also, when suggesting that the default 3200K setting is too hot (which I haven't checked, I always WB) how was the colour temperature of the lights measured? Maybe they were not 3200K.

It's my impression from Art's article that you can almost consider the successful filter to be a correction filter. All correction filters (all filters, really) involve a loss of light. The filter factor of an 80A is 2 stops. A one stop loss for a filter that corrects the IR "contamination" seems pretty reasonable and should be expected.

I'd be very curious to see the results from someone using the 0.3 filter.

By the way, I haven't been able to find anyplace selling the non-Hot Mirror version of this filter. Anyone have a suggestion?

Pete

Hello, Pete-
I'm not sure what size filter you want, but I know Filmtools in CA (Filmtools: Hollywood's source for grip, electrical, lighting, sound, video and film supplies) can special order a non-hot mirror version in a 4x4. 4x5.65 are readily available, I've found them at a number of retailers, but for the 4x4, Tiffen has to apparently cut the filter upon order, which will take approximately two months. I guess they don't have enough demand for the filter in a 4x4 to have any ready to go. I'm not sure if it's available at all in a 77mm.

This is a very important point, Serena - I didn't measure, I just used my EX1's 3200K preset. Could it be that the WB system in my specific unit is not calibrated well? Because it's obviously too hot for tungsten; when I balanced to the white card (not changing anything else), the WB settled at 2700K !

Can anyone confirm or deny the same happens with their unit(s), or is my unit defective?

It's extremely important to me to know whether I can trust the presets, as I often shoot live stage performances with other EX1's; of course we could balance all 3 to the same white card, but using a preset is much safer (I mean, with the WB switch set to memory A or B, it's all so easy to inadvertently knock the AWB button and lose the setting - while when it's in a preset position, it's 100% safe).

The difficulty with tungsten is that the colour temperature is quite sensitive to lamp voltage and age, so we can't be really sure about its colour temperature without measuring (hence the colour temperature meter). You can measure the voltage when the lamp is on and if that matches the designated lamp voltage then you won't be far out. Our supply here, for example, is supposed to be 230v AC, but varies between 220 and 245 (depending on district load) and I have seen it below 210. Stage lighting is generally on dimmers, so the CT can vary quite a bit across the stage and in time.
Today I did run a test using a RedHead QI and the camera WB, 3200 preset and colour temp meter all agreed within +/-100K . The EX1 WB gave me 3100K and I couldn't see the difference switching to the preset.
The thing is to make sure all cameras match in their settings, because matching in post is a pain. You can, as you know, pre-set any CT you find appropriate, so the 3200 factory pre-set isn't operationally critical.

Piotr,
I'm having trouble identifying exactly what problem your having because I don't know what lights you were using or for that matter how much background you may be bringing to your understanding. Please excuse me if it sounds like I'm talking down here.

It looks like you you shot the test of the chair under ordinary household tungstun bulbs which are not 3200 but closer to 2600- 2900K so of course the picture would appear red.
Alternatively Serena is right that if your voltage is lower than what even professional photo lamps are rated for (usually 3200) the same thing would happen.

This has nothing at all to do with IR contamination, just ordinary white balance and color temperature. IR is something that only affects some fabrics in an otherwise well color balanced shot.

It is interesting though that people with the EX on these boards have been complaining mostly about IR under Tungstun light rather than in daylight while using ND while complaints about the RED seem to center more about ND problems. I need to do some testing myself on this soon.

Its obvious that flourescents might not produce the same IR that tungstun but that is only a very limited solution for most people. Though for now might be something to keep in mind if you have an important shoot that you have the ability to shoot with flos.

Lenny Levy

Lenny,

No problem with talking down to me at all :)

I probably wasn't clear enough, but I do realize the middle 2 grabs posted above (at 3200K preset) are too warm due MAINLY to bad WB, not IR contamination. Basically, the left 3 grabs are without any filtering, while the 3 to the right - with some Hot Mirror filter I'm testing now (which only has none to mild effect, BTW).

If I discussed the 3200K preset vs 2700K measured CT with Serena has been because, in fact, I started worrying about my unit's WB presets being off - without any connection to the IR contamination.

Your post, however, helped me stop worrying as indeed, 3200K is more for a direct halogen light, and my shots were taken under regular home tungsten (plus red curtains in the window to block daylight). So, the 2700K is absolutely a more realistic figure for the true CT here!

Well, I did put a disclaimer in my post above these were very "quick & dirty" tests - but I should have taken more time (and thought) posting them, anyway!

Nevertheless, I think my conclusions still hold true:

- the W+B 486 filter I tested earlier is far more efficient than my currently being tested one, as it can get rid of all and any red contamination (I deliberately don't call it "IR"), but sadly is unacceptable due to the greenish vignetting at wide angles

- proper WB is essential for minimizing the red contamination, with a filter as well as without one

I guess you can agree :)

It's occurred to me that the EX1 may be exhibiting a sensitivity to a type of "metamerism" or the way a pigment or dye changes its appearance under different types of lights.

People who do critical color printing always judge the quality of a print under lights that have the spectral distribution of daylight. These lamps are carefully produced and tested, and they're checked during their lifespan to ensure high quality control. Pigments that look blue under one type of light might appear almost purple under another type of light. So printers who are picky about quality and consistency always use a standardized light source under controlled conditions (a viewing booth) to judge their work.

Because of its extended sensitivity to wavelengths in excess of 650 nanometers, tungsten lights would tend to exaggerate that quality in certain materials. Tungsten lighting's spectral distribution is mostly in the longer wavelengths. That's why what looks "black" to the human eye in tungsten light looks "red" to the EX1.

Under LED lights and fluorescents, those same materials might not exhibit the same degree of redness. And, of course, with a filter that attenuates wavelengths longer than 650 nm, that redness is also reduced.

Dean,

I think that you might correct here. I often see what the EX1 sees - a redness in the blacks of some "black fabrics" under some lighting conditions. The EX1 sees it more than me, but I can clearly see it. This does not extend to all fabrics (such as suits), but the synthetics such as nylon are the worst offenders for redness to my eye.

I guess that everyones vision is slightly different.

Dean - yes,

- the second issue of course is the ND problem , because even though you are under daylight outdoors, , normal ND filters don't cut the IR portion of the spectrum so the IR portion cumulatively and disproportionally increases with increasing strength of ND filtering.

Art Adams only addressed the latter question in his post. I've been trying to contact him privately about it but haven't gotten a response yet.

It's true that our vision doesn't simply stop working at a certain wavelength anymore than our hearing stops at a given wavelength of sound. No doubt it also varies over the population. Certainly some IR LEDs used with security cameras are visible if you look into them, you'll see a dull red glow. I think we retain some sensitivity out to 800nm.

The problem is that such wavelengths are all simply seen as red by our cameras, keep in mind that neither video or film records the wavelength of light, only the relative amounts of the primary colors.

There's one aspect to this not mentioned so far. If the EX did not retain some sensitivity beyond the visible spectrum that would preclude its use for night time wildlife photography. IR illuminators would be useless.
One type of illuminator seems to use 940nm LEDs. These are totally invisible and only work with cameras with no IR filter or one where the IR filter can be removed. This is the best system as silicon is most sensitive at 1000nm.
The other illuminator uses 850nm LEDs for cameras with fixed IR filters. These LEDs can be seen as a dull red glow. I might buy a cheap one of these to see how they perform with the EX.

Considering that normal ND's cut up up to some 680 nm, using one outdoors should create a "hole" between 680nm and where the internal hot mirror starts to act (700-750) for long reds to leak into the sensor, as the one that exists when shooting indoors, without any ND but under a lighting which is low and shifted towards red when compared with sunlight.

And indeed - today I took a closer look at some black fabrics notorious of becoming red in tungsten, but put on the ND filter and shot it in the sunlight: it's maroon, as expected !

So it seems we understand now what's happening; what's more - it's probably not another Hot Mirror that we need to prevent it (as Art Adams points out in his another article here:

ProVideo Coalition.com: Stunning Good Looks by Art Adams | Cinematography)

To the F35 (and also EX) owners, he says:

"don’t buy Hot Mirror filters for your Genesis/F35 because it’s a waste of money."

But unfortunately, in all those articles the cure, proposed for these cameras, are special kind of ND filters from Tiffen; what we REALLY need is an equally efficient filter without any ND component, as we need it for low-light shooting!

Take a careful look at page 5 of the article.
The first shots with 0.9 ND filter show extreme red shift in the fabric on the right side of the chart. I'd suggest the ND filter is making the problem worse as it's cutting visible and not far red i.e. it's in effect adding gain to the far red.
Now look at the last two shots. There's still some red shift in the fabric. The extra dye has corrected the ND out to the far red. As Art says the amount of dye has to balance the ND. Probably if it doesn't either the red shift is back or it introduces a shift in the rest of the spectrum. It's tempting to hope that a simple and cheap dye filter will cure our problem but I suspect it isn't that simple.

The 486 is a pretty complex filter with I think over 30 layers of different materials, probably each one provides a narrow notch filter which is why it can achieve such a sharp cutoff just outside the visible spectrum. Maybe our ideal filter doesn't need so many layers as we don't need IR cut however to achieve such a sharp cutoff I think we'll still need this kind of filter and that'll mean some degree of color shift at low angles. Tilting the 486 and watching the rainbow of colors it reflects I'm amazed there isn't more shifts with this filter.

That's exactly what I was trying to say - sorry for my English :)

As to the 486, it's amazing indeed how effective it is - both under tungsten, and sunlight (even with ND on). However, the low angles vignetting is not the only problem that led me to sell it away (cheaply); as I'm often using my 35 mm adapter/lens, I needed a 4x5.65" version (rather than a screw-on) to be put as the first optical element in my matte box.

From the series of Art's articles it seems that the answer would be an IR filter like Tiffen IR ND (not a hot mirror, i.e. without the dichroic coating), that cuts at some 680 nm. Not only is it the most effective on the red contamination type found on the CineAlta series, but it doesn't introduce any vignetting at wide angles. And, it's much cheaper than hot mirrors!

However, I'd prefer such a filter without any ND component to it, so that I don't lose any light at all - now, does such a beast exist?

The weakest ND one I found is : http://www.bhphotovideo.com/c/produc...y_0_3_ND_.html - just one stop light loss. The catch is that - as Art points out - those filters cannot be combined with other ND's, so we're sort of trapped...

The ideal solution would be if Sony (the upgrade kings) offered to replace the built-in ND filters with IR-ND filters. Of course they'd also change the ones on the assembly line, calling them "EX-1B" and "EX-3B" and charging more.

"The ideal solution would be if Sony (the upgrade kings) offered to replace the built-in ND filters with IR-ND filters".

Here, here! I agree.

So I suppose theres nothing for it but to get the B+W 486 filter for my EX3 advised by Brian, (thanks)

I think Brian you supplied this link of us in the UK.. B&W UV-IR Digital (486) 77....

B&W UV-IR Digital 77: Amazon.co.uk: Electronics & Photo

I saw in a post Brian you thought your LED On-board Camera light might have helped the blacks to stay black. Have to tested any more on this.

Thanks.

Anthony I found out two things lately:

1)If a potential black fabric which is turning into brown in a tungsten lit room is blasted with light from an LED on board lamp, then the black becomes black again. The reason being that LED light is overpowering the halogen / tungsten light which has a component of IR. That is why I found the Zylight 90 so effective as I can dial in any colour temp that I need so as to match the prevailing light. I did not have time to experiment much on this but I did see this effect. I generally prefer using the 486 and be able to film under the available light rather than switching on the on-board light.

2)Lately I was convinced in buying and using the warm cards. The footage does become much nicer than standard white balancing on a piece of paper. However I've noticed that if one uses the 1/2 warm filter, this will tend to enhance the IR contamination if filming under tungsten or in daylight.

Incidentally for just one instance I thought that I have solved this issue. I white balanced on the grey card that is included in the warm cards pack and I managed to see a black t-shirt as black under halogen light. I just couldn't believe it and I took another white balance and this time although it was the same colour reading of 2300K the t-shirt turned brownish. I've tried several times to get the same effect but couldn't. This one off event led me to re-confirm what others were hinting (I believe Piotr was one of them) that this IR contamination might be somehow linked to white balancing as well. It is not just a question of white balancing but probably a series of other things.

Hi Brian

Thats interesting, you could be on to something there.

I read somewhere that a newspaper, a fews days old, was good to white balance on, I don't know, I never tried it. A polystyrene cup was something else that was suggested.

Just wonder after reading the posts regarding this, have Sony themselves comeback with any new info.

It sounds to me like what you are seeing is the side-effect of "fooling" the camera. For example, by using the off-color white balance cards (or the slightly yellowed day-old newspaper), you are skewing the white balance of the camera slightly toward the blue end of the spectrum causing the blacks to "cool down" (along with all the other colors, btw) thereby making the brown-blacks appear cooler and "blacker", no?

Oh...I forgot to mention one very important observation. When I managed to restore black to black for just one instance only by taking a WB reading from a grey card, the reds in general were very much muted (obviously). Which leads to more speculation whether it is really a case where the EX cameras are very sensitive to the red colour. So in order to get decent black one will loose the vividness of the red color. Hence that is why probably some people have suggested to work out a picture profile for this issue. However this will be at a cost for the overall warmth of the picture since the reds would be curtailed.

I'm looking for the B+W 486 filter recommended. Not really sure what to order here in the UK but was wondering if this is the correct filter to get. £62.96

B+W 010 UV MRC SL 77mm Ultra Violet Filter (Multi-Resistant Coating - Slim Mount)

Thanks.

Hi, Anthony-
That filter you listed is incorrect. That one is a simple UV filter which will do nothing to reduce the IR contamination. This is the one you want:
B+W 486 UV/IR MRC SH 77mm Ultraviolet / Infrared Cut Filter

I have discussed this at length with Ryan Avery, the US rep for Schneider (B+W) filters. While he admits that there currently is no 'holy grail' filter for the EX for IR contamination, the 486 is the best option with the caveat that you cannot shoot full wide without some cyan vignetting. If you keep that in mind and shoot accordingly, this seems like the way to go. I have ordered the 4x4 version of this filter (called the Tru-Cut 680) and will post some results when I have had a chance to test it. I am hopeful that in most circumstances this filter will do the trick. One other thing: since this is a 'hot mirror' filter (it has reflective coatings) it MUST be the first filter light hits, so if you are using any other filter along with this, it must be positioned behind the 486.

I was tempted to try the Tiffen IRND filters described here:
ProVideo Coalition.com: Stunning Good Looks by Art Adams | Cinematography
but in the end went with Ryan's suggestion. The Tiffen filters cannot be used with any other ND filter (even the built-in ones on the camera) which severely limits the versatility of the filter, unless you have unlimited resources and can afford several of these filters each with a different level of ND. At around $300US each, that wasn't an attractive option.

Thank you Derek for giving me the correct link and the tips regarding using other filters along with it.

So do you think the Tru-Cut 680 might also eliminate cyan vignetting in the wide shots.

Thanks again.

Should have asked, does this filter stay on the lens at all times or are there certain times its needed, and fitted then.

Thanks.

Anthony,

When I first bought the 486 (screw-on) filter, I was hoping to be able to keep it permanently on the lens. However, considering the vignetting at wide angles and the fact no other optical element must be present in front of it, I soon realize this is not viable.

BTW, Derek is buying the 4x4" version to be used with a matte box, I assume, which is the best solution especially when one is using a 35mm adaptor/lens. If only some manufacturer came out with a non-hot mirror (i.e. without the dichroic coating which causes vignetting), neutral-ND version...

Thanks Piotr for that, not the owner of a EX3,.. just yet, so when exactly does this filter be used, indoors or out.

Just placed the order for the 486 filter. Thanks Derek BTW.

Mainly indoors, as the red contamination problem is most pronounced under tungsten light.

However, it can also be visible with some fabrics under day light, especially with strong ND filtering.

Thanks again Piotr, so theres a bit of trial and error till you get the hang of it :)

Is the 486 as effective outdoors as it is indoors. Has anyone tested that yet?

Yes Lenny - it's equally effective (100%).

Actually it is very easy - I keep the 486 in its protective plastic case in my pocket all the time - if and when I encounter the IR contamination I just screw it in. Yes it can be seen in daylight but is not so pronounced as under tungsten lights. Although it is true that the 486 gives you a slight green vignette at extreme wide angle, I'm pretty sure that in the case of event filming, the client will not notice it. We notice it because we know about it and we try to look for it. But if you are viewing the end product on a full HD 50" tv I'm sure that your eyes will mainly focus in the middle of the screen and will not notice the extreme edges. ...just my impression....

Hi Brian, again not the owner yet, of the EX3, so this can be seen right away in the EX1/3 viewfinder, blacks aren't black, so just screw the filter on when this happens.

Piotr is right.... I ordered the 4x4 version of the 486 because I use a matte box. I feel it's much easier managing and applying filters that way, plus I already own a large array of 4x4 filters. Also, then they can then be used with any lens I happen to mount on the camera.
I also agree with Piotr that you should not just leave this filter on all the time.... there are several reasons why which have already been addressed. It's best to have it on hand, and use it if/when you see the issue. Kind of like using a polarizer.... there are certain applications when a polarizer works great, but it's not something you'd want to keep on all the time. (speaking of polarizers.... make sure if you use one on the EX that it MUST be a 'circular' polarizer, and NOT a 'linear' polarizer. That is a whole other issue.....

I have seen the IR contamination in all lighting conditions, so there is no 'ideal' circumstance for this to occur. I have seen it in daylight, tungsten light, even HMI lighting. I just plan on popping the Tru-Cut filter in when I see a problem, otherwise it's in my filter kit standing by.

I haven't received my filter yet, but will be more than happy to share my experience with it when it arrives.

Happy shooting-

Yes Anthony. Once you are aware of the issue you'll see it immediately in the colour viewfinder and then you'll just pop on the filter.

I would love to use 4x4 filters instead of screw in type (especially in this case) but unfortunately do not wish to buy a large matte box just for the filters. Also I do not wish to loose the function of the lens hood as I like the ability to close of the hinges when not filming. I've seen that the Z5 has a hood supplied with the wide angle accessory that accepts large filters. Does anyone know of something similar - maybe a slim filter holder that screws in front of the lens and then the hood can be mounted on top of it?

my results, 486
 

I not long recieved my 486 filter and thought I'd share my experiences to add to the collection. I done alot of testing to see if it really cured the reddish brown problem under all sorts of different lighting, different fabrics etc and I can report that i was able to get ALL my blacks looking black however there are side effects. I actually filmed a very short clip to demonstrate how effective the filter was along with my thoughts on the side effects etc, you can check it out at 486 filter test 'quick & dirty' on Vimeo

I plan to film a proper testing at some point, this clip really is only to demonstrate what the filter does for those wondering if they should spend the money or not. Hope it helps