[Pavel]

Thank you Adrian. I noticed that the color mapping of the IR filter in NIK is more sophisticated than I described. I was surprised for example, that the green of the pine trees remained dark, while the green leaves of the tree right next to it went white. On big stems of grass, there is a fairly sharp transition from almost white (zone IX my guess) derived from sunlit green (about Zone VII to VIII i am guessing) to dark (perhaps zone II) from less well lit grass (my guess zone V).

Adrian, I tried to check out your site, but it does not seem to be populated with photos or at least i could not figure out how to access the photos.

Thank you for writing this very informative response to my question. I think I understand a lot better. I think that for now, I will experiment with the software filter and leave the hardware purchase for some later date. I am swayed by the low cost (no cost actually - I do have the software) and the convenience of capturing the images (no need to carry extra camera body, no need for a tripod most of the time, no need to put on and take of the filter each time i wish to refocus/recompose, multiple use of the same image - color, straight BW, faw IR.). I will be interested to hear why my decision does/does not make sense.

Pavel