diff --git a/src/cmake/externalpackages.cmake b/src/cmake/externalpackages.cmake
index e7261af3..195f46cb 100644
--- a/src/cmake/externalpackages.cmake
+++ b/src/cmake/externalpackages.cmake
@@ -102,7 +102,6 @@ if (MSVC AND NOT LINKSTATIC)
     add_definitions (-DOPENEXR_DLL) # Is this needed for new versions?
 endif ()
 
-
 # JPEG -- prefer Turbo-JPEG to regular libjpeg
 checked_find_package (JPEGTurbo
                       DEFINITIONS -DUSE_JPEG_TURBO=1
@@ -145,7 +144,7 @@ checked_find_package (HDF5
                    ISDEPOF      Field3D)
 checked_find_package (OpenColorIO
                    DEFINITIONS  -DUSE_OCIO=1 -DUSE_OPENCOLORIO=1)
-checked_find_package (OpenCV
+checked_find_package (OpenCV CONFIG
                    DEFINITIONS  -DUSE_OPENCV=1)
 
 # Intel TBB
@@ -155,7 +154,7 @@ checked_find_package (TBB 2017
                    ISDEPOF      OpenVDB)
 
 checked_find_package (DCMTK VERSION_MIN 3.6.1)  # For DICOM images
-checked_find_package (FFmpeg VERSION_MIN 2.6)
+checked_find_package (FFMPEG)
 checked_find_package (Field3D
                    DEPS         HDF5
                    DEFINITIONS  -DUSE_FIELD3D=1)
@@ -163,18 +162,25 @@ checked_find_package (GIF
                       VERSION_MIN 4
                       RECOMMEND_MIN 5.0
                       RECOMMEND_MIN_REASON "for stability and thread safety")
-checked_find_package (Libheif VERSION_MIN 1.3)  # For HEIF/HEIC format
-checked_find_package (LibRaw
+checked_find_package (libheif CONFIG)  # For HEIF/HEIC format
+checked_find_package (LibRaw CONFIG
                       RECOMMEND_MIN 0.18
                       RECOMMEND_MIN_REASON "for ACES support and better camera metadata"
-                      PRINT LibRaw_r_LIBRARIES )
-checked_find_package (OpenJpeg VERSION_MIN 2.0)
+                      PRINT LibRaw_LIBRARIES )
+checked_find_package (OpenJPEG CONFIG)
 checked_find_package (OpenVDB
                       VERSION_MIN 5.0
                       DEPS         TBB
                       DEFINITIONS  -DUSE_OPENVDB=1)
-checked_find_package (PTex)
-checked_find_package (WebP)
+checked_find_package (ptex CONFIG)
+set(PTEX_FOUND ${ptex_FOUND})
+set(PTEX_LIBRARIES Ptex::Ptex)
+checked_find_package (WebP CONFIG)
+if(WebP_FOUND)
+    set(WEBP_FOUND TRUE)
+    add_library(WebP::WebP ALIAS WebP::webp)
+    add_library(WebP::WebPDemux ALIAS WebP::webpdemux)
+endif()
 
 option (USE_R3DSDK "Enable R3DSDK (RED camera) support" OFF)
 checked_find_package (R3DSDK)  # RED camera
@@ -287,5 +293,7 @@ macro (find_or_download_fmt)
     checked_find_package (fmt REQUIRED)
 endmacro()
 
-find_or_download_fmt()
+find_package(fmt CONFIG REQUIRED)
+get_property(FMT_INCLUDES TARGET fmt::fmt PROPERTY INTERFACE_INCLUDE_DIRECTORIES)
+checked_find_package (fmt CONFIG REQUIRED)
 include_directories (${FMT_INCLUDES})
diff --git a/src/ffmpeg.imageio/CMakeLists.txt b/src/ffmpeg.imageio/CMakeLists.txt
index 6cf07636..8e77b1ed 100644
--- a/src/ffmpeg.imageio/CMakeLists.txt
+++ b/src/ffmpeg.imageio/CMakeLists.txt
@@ -11,7 +11,7 @@ if (NOT MSVC)
                              PROPERTIES COMPILE_FLAGS "-Wno-deprecated-declarations")
 endif()
 
-if (FFmpeg_FOUND)
+if (FFMPEG_FOUND)
     add_oiio_plugin (ffmpeginput.cpp
                      INCLUDE_DIRS ${FFMPEG_INCLUDES}
                      LINK_LIBRARIES ${FFMPEG_LIBRARIES}
diff --git a/src/field3d.imageio/CMakeLists.txt b/src/field3d.imageio/CMakeLists.txt
index a9e54e3f..00fac073 100644
--- a/src/field3d.imageio/CMakeLists.txt
+++ b/src/field3d.imageio/CMakeLists.txt
@@ -10,6 +10,6 @@ if (Field3D_FOUND)
     add_oiio_plugin (field3dinput.cpp field3doutput.cpp
                      INCLUDE_DIRS ${FIELD3D_INCLUDES}
                      LINK_LIBRARIES Field3D::Field3D
-                                    # ${HDF5_LIBRARIES}
+                                    ${HDF5_LIBRARIES}
                                     ${SZIP_LIBRARY})
 endif()
diff --git a/src/heif.imageio/CMakeLists.txt b/src/heif.imageio/CMakeLists.txt
index fed80015..884d1312 100644
--- a/src/heif.imageio/CMakeLists.txt
+++ b/src/heif.imageio/CMakeLists.txt
@@ -4,7 +4,7 @@
 
 if (Libheif_FOUND)
     add_oiio_plugin (heifinput.cpp heifoutput.cpp
-                     LINK_LIBRARIES Libheif::Libheif
+                     LINK_LIBRARIES heif
                      DEFINITIONS "-DUSE_HEIF=1")
 else ()
     message (WARNING "heif plugin will not be built")
diff --git a/src/raw.imageio/CMakeLists.txt b/src/raw.imageio/CMakeLists.txt
index 81a0ff54..23326a0a 100644
--- a/src/raw.imageio/CMakeLists.txt
+++ b/src/raw.imageio/CMakeLists.txt
@@ -5,7 +5,7 @@
 if (LIBRAW_FOUND)
     add_oiio_plugin (rawinput.cpp
                      INCLUDE_DIRS ${LibRaw_INCLUDE_DIR}
-                     LINK_LIBRARIES ${LibRaw_r_LIBRARIES}
+                     LINK_LIBRARIES ${LibRaw_LIBRARIES}
                      DEFINITIONS "-DUSE_LIBRAW=1")
 else ()
     message (WARNING "Raw plugin will not be built")