[Fernando Tella]

Don't use the alpha image as a clipmap in the transmittance slot which only clips completely white pixels. Use it as a weightmap between two layers, one ghost, the other the leaf texture. This way you'll get more control of the clip.

[Fernando Tella]

I don't know if the new plugin translates those materials to maxwell. Anyway from each tiff you souhld obtain three images: black and white image for opacity (in rgb mode and I would make it jpg); you can take it from the alpha channel; the greyscale image for bump (in rgb mode too); you can desaturate the tiff and save it as a jpg (or tiff wiwthout alpha); and finally save the color image for diffuse as a jpg or tif without alpha.