diff --git a/Source/EMsoftOOLib/mod_filters.f90 b/Source/EMsoftOOLib/mod_filters.f90
index d5c2c04..e04ec7d 100644
--- a/Source/EMsoftOOLib/mod_filters.f90
+++ b/Source/EMsoftOOLib/mod_filters.f90
@@ -1285,12 +1285,12 @@ recursive subroutine HannWindow(roi_size, window, alpha)
 ! this version implements the 2D HannWindow function from Mathematica
 ! the assumption is that roi_size is an odd number
   r = (roi_size-1)/2
-  fr = 1.D0/dble(r)
+  fr = 1.D0/dble(2*r)
   window = 0.D0
-  do i=-r/2,r/2
+  do i=-r,r
     cx = cos(2.D0*cPi*dble(i)*fr)
     hx = alpha*(1.D0-cx) + cx
-    do j=-r/2,r/2
+    do j=-r,r
       cy = cos(2.D0*cPi*dble(j)*fr)
       window(i+r+1,j+r+1) = hx * ( alpha*(1.D0-cy) + cy )
     end do
diff --git a/Source/EMsoftOOLib/program_mods/mod_4DEBSD.f90 b/Source/EMsoftOOLib/program_mods/mod_4DEBSD.f90
index dfbb3c2..5e5241f 100644
--- a/Source/EMsoftOOLib/program_mods/mod_4DEBSD.f90
+++ b/Source/EMsoftOOLib/program_mods/mod_4DEBSD.f90
@@ -1748,7 +1748,7 @@ subroutine EBSD4D_(self, EMsoft, progname, HDFnames)
 
 ! get the virtual detector coordinates
         if (trim(nml%VDreference).eq.'MPat') then 
-          ival = iii*nml%ipf_wd + jj-1
+          ival = (iii-1)*nml%ipf_wd + jj
           VDpx = nint(VDpositions(1,ival))
           VDpy = nint(VDpositions(2,ival))
         else