Neatimage 5.6, I don't know if 5.8 has the same problem.
When i save the image in TIFF some details are lost
look here:
capture of the screen after filtration
capture of the screen after saving the above image in TIFF format with NI
(I can provide the original file Image)
Look at the eye center... the color degradation.
To avoid this for the moment I use the function Edit->Copy of NI
and then paste in Photoshop to save in TIFF format without loss.