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October 19th, 2008, 04:39 PM | #31 |
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October 19th, 2008, 05:39 PM | #32 |
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Not Available Yet
Schneider has not responded to my e-mail request to order the 77mm True-Cut filter. There is no price or delivery information at this time. I'm pretty sure that Schneider is aware of the need and will let us know when they are ready to deliver.
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October 19th, 2008, 05:54 PM | #33 | |
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Quote:
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October 19th, 2008, 06:52 PM | #34 |
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This is often stated, so must be so. But why is it so? If the filter is placed downstream of other optical elements that will reflect IR reflected by the filter, how is that second reflection altered in such a way that it gets passed by the IR cut filter? If the filter reflects 100% of IR in the specified bandwidth, then any reflected IR in the bandwidth will get reflected again (and not passed). If 90% gets reflected, then on the second go 90% of 10% gets bounced back again, and so on. How do other filters change the bandwidth of the IR component prior to meeting the IR cut filter, to make it less effective? True a filter does not have a square cut-off characteristic, but how does that affect the argument?
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October 19th, 2008, 07:16 PM | #35 |
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Serena
The filter works by using interference principles of multilayers to reflect the desired wavelengths instead of letting them pass on. The layers are spaced properly for the wavelengths desired. Light entering the filter straight in are properly affected. Light entering from an angle see the spacing of the layers differently because of the angle and therefore do no interfere properly. When the filter is the first optical element the reflected light disappears harmlessly into never never land. If the filter is behind other optical elements it is possible for those elements to scatter and reflect the light back towards the filter in such a way that they enter the filter at an angle and get through. Lens designs this kind of complexity have to be carefully designed to prevent such backscattering in the first place and adding a mirror arbitrarily in optical path is almost a certain formula for problems. These problems could be flare, ghosting, multiple hot spots, etc. That is not to say that it isn't possible for something added in the optical path to work but the chances are it won't fix the IR problem without causing another or even worse multiple problems. |
October 19th, 2008, 07:32 PM | #36 | |
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IR filter ...
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October 20th, 2008, 02:45 AM | #37 |
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anyone tried using a tungsten to daylight colour correction filter and then shooting with a daylight white balance. This would allow the use of a stronger red reduction via the filter although it would push up the cameras red sensitivity.
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Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com |
October 27th, 2008, 10:40 AM | #38 | |
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We taken considerations regarding the EX-3 and the True-Cut IR 750 into account. Our engineers have worked to deduce the problem Les experienced. We value our users feedback and are always looking for ways to exceed your expectations with regard to quality and performance for which we are known. If you already own a True-Cut IR 750 and have not had any problems, then you are ok. You can buy this filter at any of our authorized DV Info sponsors. Reference the description and part number: 77mm True-Cut IR 750 68-121077 List Price: $250.00 Ryan Avery Schneider Optics |
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October 27th, 2008, 10:42 AM | #39 | |
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Ryan Avery Schneider Optics |
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October 28th, 2008, 06:20 AM | #40 |
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Ryan, how do you feel the 489 works for IR cut?
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November 3rd, 2008, 11:45 AM | #41 |
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The 489 was not designed with the cut rates necessary for the EX1/EX3. It will create a blue cast on wider angle incidences of light. This filter was designed mostly for industrial applications.
I had one user buy it without consulting anyone and it wound up not working for his EX1. We are looking at the IR issues presented by the EX1/EX3. The True-Cut 750 IR seems to work in some cases but not others. Most users we have sold this filter to have not complained and use it extensively. As the test pictures show here in this thread, there are some fabrics that the IR light is more of an issue. More to follow soon. Ryan Avery Schneider Optics |
February 9th, 2009, 10:07 AM | #42 | |
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To Ryan Avery
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Thanks! |
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February 9th, 2009, 12:44 PM | #43 |
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Ryan I too am anxious to know if there were any developments. I've just bought the 486 and I feel that I've wasted my money. It does correct the IR contamination but produces the horrible green vignetting which is not that easy to correct in post (or at least it's time consuming). If to correct one problem another one is induced than it is a scenario of "out of the frying pan into the fire..."!
I'm really dreaming of that elusive IR filter that settles once and for all this headache. |
February 9th, 2009, 04:51 PM | #44 |
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we all are!! just there doesnt seem to be one right now!
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February 10th, 2009, 06:25 PM | #45 |
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If ...
If an IR filter does not do the trick, I wonder if sony can do an internal software adjustment to cut off the IR levels in the EX1/3? This may be an option, no?
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