Hi, actually there is nothing wrong with your purchase and usage of 850nm IR filter. Nice black and white IR photos you've got here
The 850nm Chinese-made IR filter is considered strong as it blocks out all available lights except IR thus you captured "PURE" infrared lights and therefore you get only monochrome photos.
(The following info below is extracted from
http://forums.dpreview.com/forums/read.asp?forum=1021&message=32950434)
The IR filters fall into those same three categories:
1.) Strong filters include the Lee 87, Tiffen 87, Wratten 87 (indeed, anything with "87" in its name), the Hoya RM90, B+W 093, and Heliopan 5780, 5830, and 5850. These filters don't even begin to transmit light until you're in the "real" infrared at 740nm or so, and don't reach maximum transmission until someplace over 800nm. So, they all require a "broken" or "weak" filter camera. The IR results are pretty much monochrome, because the camera's red, green, and blue filters have all failed at IR wavelengths and are all passing IR.
2.) Weak filters include the Hoya R72, Heliopan 5715 filters, and the original Kodak Wratten 89B (and hopefully, the Cokin 007, a Wratten 89B "clone"). They only begin transmitting noticeable light around 700nm, are up to 50% at 715nm or 720nm, and don't reach 90% until around 740nm. Because a camera's red filter passes more light in the 700-720nm range than the green or blue filters do, you get "false color", with some deep BVR (barely visible red) contributing to the red channel, while the green and blue get "pure" infrared.
3.) Broken filters include the B+W 092 and (apparently) the new Singh-Ray I-Ray. They start passing light down around 650nm, reach 50% by 695, and 90% by 720. That means that on cameras with good IR cut filters, what you get is a little "blip" of BVR from 680-700nm, where the camera's response and the filter's response overlap. BVR filters only produce something that looks like a "real" IR picture on a "broken" camera, or a camera that has been modified for IR. They work great on IR film. On a camera with a strong filter, they produce so much stronger BVR response in the red channel that you can't get good "false color". Your only choices are totally blow the red channel and extract your IR from the green and blue channels, or expose the red channel properly and "settle" for a BVR image.
