It works! The DB940 filter now also fits my favorite lens – the Nikon 50mm f/1.8.
Since the diameter of the filter is very small even for the spot behind the lens, I thought that I would inevitably have to use the cheap and rather unsuitable (for FX) 18-55mm lens with my “new” Blue Trees filter. Fortunately, I don’t.
Although there are gaps all around the filter, the diameter is enough to shoot at about f/5.6. As you know, the larger the f-number, the smaller the aperture, so it doesn’t really matter if you put too small a filter on the glass, as long as you don’t shoot with the aperture wide open.
I tested a little more with different combos and found the following addition to DB940 also very appealing: Medium Amber from Lee Filters. This combo also generates blue vegetation and blue skies straight out of the camera.