Click image for larger view.
Hoya R72 filter. ISO 200, 8sec exposure and I think it was about f/8.
No modification to image other than convert to B&W and minor levels adjustment.
Note that this OM 21mm f/3.5, unlike the other less wide angle OM lenses, creates a radial CA-like effect visible at high contrast edges such as at the tops of the trees. This OM lens is a beautiful compact ultra wide but alas is not so suitable for IR work.