I bought this to use on my Monochrom Typ 246. I have all the color filters Leica makes—yellow, orange and (now) green—and a red one. Most articles on filters say the green filter is the least used, but does have a place for lightening slightly the green tones in an image. So it's used most of the time in a scene with foliage. I use it for that, and it does lighten the tones some, but not a lot. (I'd attach a with/without comparison if I could here.) I do a fair amount of post processing to get the tonal relationships I want. One use where this filter shines is taking a photo of a red rose surrounded by green leaves. In that instance, it darkens the rose and lightens the leaves, resulting in a much more pleasing photo.