May you tell me what kind of additional filters you used to improve the performance, what kind of performance do you mean? You know the more filter you add on the lens the more degrading to you image, why didn't you converted your camera to full spectrum at first step, and then use different nm of different IR filter to archive what you would like to have. For example, you add a 720nm on top of your already converted camera with 590nm, then the IR ray of 590nm will be blocked by the 720nm filter, so the 590nm in the camera doesn't do any thing to your final image that will be the image from the 720nm not by combination of both! The only result will be a degrading image. Same as using the 830/850nm, the image will be just back and white, no color at all./850
I have 590nm; 680nm, 720nm, plus 850nm to work on my self home converted P&S compact camera. I like the operating of this simple set up. Good Luck and Happy Shooting!

May you tell me what kind of additional filters you used to improve the performance, what kind of performance do you mean? You know the more filter you add on the lens the more degrading to you image, why didn't you converted your camera to full spectrum at first step, and then use different nm of different IR filter to archive what you would like to have. For example, you add a 720nm on top of your already converted camera with 590nm, then the IR ray of 590nm will be blocked by the 720nm filter, so the 590nm in the camera doesn't do any thing to your final image that will be the image from the 720nm not by combination of both! The only result will be a degrading image. Same as using the 830/850nm, the image will be just back and white, no color at all./850
I have 590nm; 680nm, 720nm, plus 850nm to work on my self home converted P&S compact camera. I like the operating of this simple set up. Good Luck and Happy Shooting!

When you use 859nm, almost all colour is removed and you get a B&W image.
As you go down, more color is added. I had my first camera at 720nm, and that allows the standard IR type photo, the trees are magenta. Of course, you have to play a bit with it, but that is the case.
As you go down, you get more colour, the photo that I posted is with 590nm. The one that I posted at the start of this thread is 590nm, with the red-blue cross. There is a lot more visable colour information in the picture, hence the change in colour.

One thing that you have to keep in mind is that the standard colour management took is to do the red-blue cross. You have to change the red chanel to 0% red and 100% blue, and the blue channel to 100% red and 0% blue.

Here is a better idea of what happens...

https://www.lifepixel.com/infrared-filters-choices