Schneider TRUE-CUT IR-750
- Thread starter dpryke
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Barry_Green
Moderator
That's about as useful as when people write in and say "get a mac."
True that the 300 doesn't have the IR problem, but it does have more skew than the EX1 in 1080/24p, so it's not necessarily a direct substitution... and besides, sometimes people have already bought and they're trying to make their system work with what they've got.
So let the folks who want to talk about IR filters, do so in peace, please.
True that the 300 doesn't have the IR problem, but it does have more skew than the EX1 in 1080/24p, so it's not necessarily a direct substitution... and besides, sometimes people have already bought and they're trying to make their system work with what they've got.
So let the folks who want to talk about IR filters, do so in peace, please.
Thanks Barry....
It looks as if the 486 filter is the best option right now. Not a perfect one, but the best.
I was thinking of something during an interview today. What is it about flos that don't seem to cause the IR problem. I was running a test with tungsten light and got the problem. I turned on the overhead flos, got a new white balance and the blacks were fine. Do the blacks have the same IR effect using a Kinoflo instead of tungsten. I know both can have the same color temp, but what is it about the flos that was OK. It can't be a color temp thing if people are having the problem in bright sunlight. It seems that there is no consistency to the problem. I also was wondering if you put a plus green on tungsten (like to balance to flos) would that have an effect. What is it about the fabric. I shot my tripod bag, duveteen, and a shirt. The duveteen was fine but the others were brown.
Just a flow of thoughts...
It looks as if the 486 filter is the best option right now. Not a perfect one, but the best.
I was thinking of something during an interview today. What is it about flos that don't seem to cause the IR problem. I was running a test with tungsten light and got the problem. I turned on the overhead flos, got a new white balance and the blacks were fine. Do the blacks have the same IR effect using a Kinoflo instead of tungsten. I know both can have the same color temp, but what is it about the flos that was OK. It can't be a color temp thing if people are having the problem in bright sunlight. It seems that there is no consistency to the problem. I also was wondering if you put a plus green on tungsten (like to balance to flos) would that have an effect. What is it about the fabric. I shot my tripod bag, duveteen, and a shirt. The duveteen was fine but the others were brown.
Just a flow of thoughts...
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Barry_Green
Moderator
The IR problem is because the sensor is sensitive to infrared light. Daylight typically doesn't have much infrared, it's a lot heavier in UV (remember the color spectrum, red-orange-yellow-green-blue-violet). Infrared is off the visible spectrum on the red side, UV is off the visible spectrum on the blue side.
Fluos don't put out much IR, typically. HMIs don't put out much IR. But tungsten, being a reddish light, is heavy on the IR.
IR is more heat energy than light energy, and tungsten spews out more of its energy in heat than any other light source, so there's tons of IR.
So it's not the fabric that's the problem, necessarily... it's the dyes in the fabric that's bouncing the IR back at the camera. Some fabrics absorb it, some reflect it. If it's absorbed (like your duvetyne) then there's no problem. But if it's reflected back to the camera, that's when you might run into a problem. Some cameras (like the Sony V1U and the HPX300) have IR filtration that blocks all the IR, so it doesn't matter what kind of fabrics you use etc., the camera is immune to IR. But some (like the Red and EX1 and VariCam) have quite a bit of sensitivity to IR, so when you use a fabric that reflects IR, the camera sees the infrared as a reddish pollution to the blacks.
The Tru-Cut and hot mirror and other IR filters are an attempt to supplement the camera's inadequate IR filtering. Unfortunately there have been a few bumps along the way in trying to find a "perfect" solution; some filters introduce green vignetting in the image, etc. I'm not sure where the current status of IR filtration for the EX1/EX3 stands at the moment, if they've found one that's ideal or if the search continues...
Fluos don't put out much IR, typically. HMIs don't put out much IR. But tungsten, being a reddish light, is heavy on the IR.
IR is more heat energy than light energy, and tungsten spews out more of its energy in heat than any other light source, so there's tons of IR.
So it's not the fabric that's the problem, necessarily... it's the dyes in the fabric that's bouncing the IR back at the camera. Some fabrics absorb it, some reflect it. If it's absorbed (like your duvetyne) then there's no problem. But if it's reflected back to the camera, that's when you might run into a problem. Some cameras (like the Sony V1U and the HPX300) have IR filtration that blocks all the IR, so it doesn't matter what kind of fabrics you use etc., the camera is immune to IR. But some (like the Red and EX1 and VariCam) have quite a bit of sensitivity to IR, so when you use a fabric that reflects IR, the camera sees the infrared as a reddish pollution to the blacks.
The Tru-Cut and hot mirror and other IR filters are an attempt to supplement the camera's inadequate IR filtering. Unfortunately there have been a few bumps along the way in trying to find a "perfect" solution; some filters introduce green vignetting in the image, etc. I'm not sure where the current status of IR filtration for the EX1/EX3 stands at the moment, if they've found one that's ideal or if the search continues...
Has anyone used this filter:
http://www.filmtools.com/schneider-optics-77e-infrared-cut-filter-486-65-031976.html
Is there any difference between this and what we have already been talking about?
http://www.filmtools.com/schneider-optics-77e-infrared-cut-filter-486-65-031976.html
Is there any difference between this and what we have already been talking about?
GuyB
Well-known member
That filter is the one we have all been talking about, its the 486 available in standard and thin and also I think the same filter as the 4x4 77(? or something similar).
As far as I understand, this filter was not "Designed exclusively for the Sony EX cameras", the filter was around well before the cameras were on the market and unless I am wrong, it is very unprofessional of that site to claim it was designed for the EX. It is probably the best current choice for the EX, but it is known to introduce a green corner and side vignette when the lens is wide. Fortunately this is hidden in the footage much easier than the IR contamination that would be otherwise visible.
As far as I understand, this filter was not "Designed exclusively for the Sony EX cameras", the filter was around well before the cameras were on the market and unless I am wrong, it is very unprofessional of that site to claim it was designed for the EX. It is probably the best current choice for the EX, but it is known to introduce a green corner and side vignette when the lens is wide. Fortunately this is hidden in the footage much easier than the IR contamination that would be otherwise visible.
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Thats the one I bought...... Seems good! Stock lens hood fits over it fine. I bought it 2 weeks ago from Filmtools and was told it was the last one in stock.
frisco