I posted this answer yesterday and for some reason it did not show here.
a Tiff stack file is basically a stack of images but it needs to be converted to a binary coded file.
here is a place to read about how to do that. I have not done this before but it may work.
It looks as though it is a long process. you would need to reduce the pixels and and reduce the resolution.
can you post on or two of the images?
are you trying to convert an MRI ?http://talesofa3dprinter.blogspot.com/2 ... -file.html