diff --git a/src/common/history.c b/src/common/history.c
index 3e11fe27211c..b58f8bb002fb 100644
--- a/src/common/history.c
+++ b/src/common/history.c
@@ -92,6 +92,7 @@ void dt_history_delete_on_image_ext(int32_t imgid, gboolean undo)
 
   /* make sure mipmaps are recomputed */
   dt_mipmap_cache_remove(darktable.mipmap_cache, imgid);
+  dt_image_reset_final_size(imgid);
 
   /* remove darktable|style|* tags */
   dt_tag_detach_by_string("darktable|style%", imgid);
@@ -167,6 +168,7 @@ int dt_history_load_and_apply(const int imgid, gchar *filename, int history_only
 
     dt_image_cache_write_release(darktable.image_cache, img, DT_IMAGE_CACHE_SAFE);
     dt_mipmap_cache_remove(darktable.mipmap_cache, imgid);
+    dt_image_reset_final_size(imgid);
   }
   return 0;
 }
@@ -739,6 +741,7 @@ int dt_history_copy_and_paste_on_image(int32_t imgid, int32_t dest_imgid, gboole
   dt_image_synch_xmp(dest_imgid);
 
   dt_mipmap_cache_remove(darktable.mipmap_cache, dest_imgid);
+  dt_image_reset_final_size(imgid);
 
   /* update the aspect ratio if the current sorting is based on aspect ratio, otherwise the aspect ratio will be
      recalculated when the mimpap will be recreated */
diff --git a/src/common/image.c b/src/common/image.c
index ba8608aa7043..cff27e2e6c82 100644
--- a/src/common/image.c
+++ b/src/common/image.c
@@ -383,16 +383,54 @@ void dt_image_set_location_and_elevation(const int32_t imgid, dt_image_geoloc_t
   dt_image_cache_write_release(darktable.image_cache, image, DT_IMAGE_CACHE_SAFE);
 }
 
+void dt_image_reset_final_size(const int32_t imgid)
+{
+  dt_image_t *imgtmp = dt_image_cache_get(darktable.image_cache, imgid, 'w');
+  imgtmp->final_width = imgtmp->final_height = 0;
+  dt_image_cache_write_release(darktable.image_cache, imgtmp, DT_IMAGE_CACHE_RELAXED);
+}
+
 gboolean dt_image_get_final_size(const int32_t imgid, int *width, int *height)
 {
-  dt_develop_t dev;
+  // get the img strcut
+  dt_image_t *imgtmp = dt_image_cache_get(darktable.image_cache, imgid, 'r');
+  dt_image_t img = *imgtmp;
+  dt_image_cache_read_release(darktable.image_cache, imgtmp);
+  // if we already have computed them
+  if(img.final_height > 0 && img.final_width > 0)
+  {
+    *width = img.final_width;
+    *height = img.final_height;
+    return 0;
+  }
+
+  // special case if we try to load embedded preview of raw file
 
+  // the orientation for this camera is not read correctly from exiv2, so we need
+  // to go the full path (as the thumbnail will be flipped the wrong way round)
+  const int incompatible = !strncmp(img.exif_maker, "Phase One", 9);
+  if(!img.verified_size && !dt_image_altered(imgid) && !dt_conf_get_bool("never_use_embedded_thumb")
+     && !incompatible)
+  {
+    // we want to be sure to have the real image size.
+    // some raw files need a pass via rawspeed to get it.
+    char filename[PATH_MAX] = { 0 };
+    gboolean from_cache = TRUE;
+    dt_image_full_path(imgid, filename, sizeof(filename), &from_cache);
+    imgtmp = dt_image_cache_get(darktable.image_cache, imgid, 'w');
+    dt_imageio_open(imgtmp, filename, NULL);
+    imgtmp->verified_size = 1;
+    img = *imgtmp;
+    dt_image_cache_write_release(darktable.image_cache, imgtmp, DT_IMAGE_CACHE_RELAXED);
+  }
+
+  // and now we can do the pipe stuff to get final image size
+  dt_develop_t dev;
   dt_dev_init(&dev, 0);
   dt_dev_load_image(&dev, imgid);
-  const dt_image_t *img = &dev.image_storage;
 
   dt_dev_pixelpipe_t pipe;
-  int wd = img->width, ht = img->height;
+  int wd = img.width, ht = img.height;
   int res = dt_dev_pixelpipe_init_dummy(&pipe, wd, ht);
   if(res)
   {
@@ -409,8 +447,11 @@ gboolean dt_image_get_final_size(const int32_t imgid, int *width, int *height)
   }
   dt_dev_cleanup(&dev);
 
-  *width = wd;
-  *height = ht;
+  imgtmp = dt_image_cache_get(darktable.image_cache, imgid, 'w');
+  imgtmp->final_width = *width = wd;
+  imgtmp->final_height = *height = ht;
+  dt_image_cache_write_release(darktable.image_cache, imgtmp, DT_IMAGE_CACHE_RELAXED);
+
   return res;
 }
 
@@ -461,6 +502,7 @@ void dt_image_set_flip(const int32_t imgid, const dt_image_orientation_t orienta
   sqlite3_finalize(stmt);
 
   dt_mipmap_cache_remove(darktable.mipmap_cache, imgid);
+  dt_image_reset_final_size(imgid);
   // write that through to xmp:
   dt_image_write_sidecar_file(imgid);
   }
@@ -1195,6 +1237,7 @@ uint32_t dt_image_import_lua(const int32_t film_id, const char *filename, gboole
 void dt_image_init(dt_image_t *img)
 {
   img->width = img->height = img->verified_size = 0;
+  img->final_width = img->final_height = 0;
   img->crop_x = img->crop_y = img->crop_width = img->crop_height = 0;
   img->orientation = ORIENTATION_NULL;
   img->legacy_flip.legacy = 0;
diff --git a/src/common/image.h b/src/common/image.h
index 9b3119faabc0..853a825deeb8 100644
--- a/src/common/image.h
+++ b/src/common/image.h
@@ -153,7 +153,7 @@ typedef struct dt_image_t
   // common stuff
 
   // to understand this, look at comment for dt_histogram_roi_t
-  int32_t width, height, verified_size;
+  int32_t width, height, verified_size, final_width, final_height;
   int32_t crop_x, crop_y, crop_width, crop_height;
 
   // used by library
@@ -235,6 +235,7 @@ void dt_image_set_flip(const int32_t imgid, const dt_image_orientation_t user_fl
 dt_image_orientation_t dt_image_get_orientation(const int imgid);
 /** get max width and height of the final processed image with its current hisotry stack */
 gboolean dt_image_get_final_size(const int32_t imgid, int *width, int *height);
+void dt_image_reset_final_size(const int32_t imgid);
 /** set image location lon/lat */
 void dt_image_set_location(const int32_t imgid, dt_image_geoloc_t *geoloc);
 /** get image location lon/lat */
diff --git a/src/common/mipmap_cache.c b/src/common/mipmap_cache.c
index 764fdd9bae47..99009883f9be 100644
--- a/src/common/mipmap_cache.c
+++ b/src/common/mipmap_cache.c
@@ -317,47 +317,11 @@ void dt_mipmap_cache_allocate_dynamic(void *data, dt_cache_entry_t *entry)
   {
     if(mip == DT_MIPMAP_8)
     {
-      const uint32_t imgid = get_imgid(entry->key);
-      if(!dt_image_altered(imgid))
-      {
-        // the image has not been been altered, so output size = input size
-        // and the orientation doesn't matter here
-        const dt_image_t *img2 = dt_image_cache_get(darktable.image_cache, imgid, 'r');
-        entry->data_size = sizeof(struct dt_mipmap_buffer_dsc) + (img2->width + 4) * (img2->height + 4) * 4;
-        dt_image_cache_read_release(darktable.image_cache, img2);
-      }
-      else
-      {
-        // we first need to get the final output size of our image
-        // let's create a dummy pipe for that
-        const dt_image_t *img2 = dt_image_cache_get(darktable.image_cache, imgid, 'r');
-        dt_image_t imgtmp = *img2;
-        dt_image_cache_read_release(darktable.image_cache, img2);
-        dt_develop_t dev;
-        dt_dev_init(&dev, 0);
-        dt_dev_load_image(&dev, imgid);
-        dt_dev_pixelpipe_t pipe;
-        const int res = dt_dev_pixelpipe_init_dummy(&pipe, imgtmp.width, imgtmp.height);
-        if(res)
-        {
-          // set mem pointer to 0, won't be used.
-          dt_dev_pixelpipe_set_input(&pipe, &dev, NULL, imgtmp.width, imgtmp.height, 1.0f);
-          dt_dev_pixelpipe_create_nodes(&pipe, &dev);
-          dt_dev_pixelpipe_synch_all(&pipe, &dev);
-          dt_dev_pixelpipe_get_dimensions(&pipe, &dev, pipe.iwidth, pipe.iheight, &pipe.processed_width,
-                                          &pipe.processed_height);
-          dt_dev_pixelpipe_cleanup(&pipe);
-          // we enlarge the output size by 4 to handle rounding errors in mipmap computation
-          entry->data_size
-              = sizeof(struct dt_mipmap_buffer_dsc) + (pipe.processed_width + 4) * (pipe.processed_height + 4) * 4;
-        }
-        else
-        {
-          // for some raison pipeline didn't succeed, let's allocate huge memory
-          entry->data_size = cache->buffer_size[mip];
-        }
-        dt_dev_cleanup(&dev);
-      }
+      int imgfw, imgfh;
+      imgfw = imgfh = 0;
+      // be sure that we have the right size values
+      dt_image_get_final_size(get_imgid(entry->key), &imgfw, &imgfh);
+      entry->data_size = sizeof(struct dt_mipmap_buffer_dsc) + (imgfw + 4) * (imgfh + 4) * 4;
     }
     else if(mip <= DT_MIPMAP_F)
     {
@@ -1243,25 +1207,13 @@ static void _init_8(uint8_t *buf, uint32_t *width, uint32_t *height, float *isca
     }
     else
     {
-      // we want to be sure to have the real image size.
-      // some raw files need a pass via rawspeed to get it.
-      dt_image_t *img2 = dt_image_cache_get(darktable.image_cache, imgid, 'r');
-      const int verified_size = img2->verified_size;
-      dt_image_cache_read_release(darktable.image_cache, img2);
-      if(!verified_size)
-      {
-        img2 = dt_image_cache_get(darktable.image_cache, imgid, 'w');
-        dt_imageio_open(img2, filename, NULL);
-        img2->verified_size = 1;
-        dt_image_cache_write_release(darktable.image_cache, img2, DT_IMAGE_CACHE_RELAXED);
-      }
       uint8_t *tmp = 0;
       int32_t thumb_width, thumb_height;
       res = dt_imageio_large_thumbnail(filename, &tmp, &thumb_width, &thumb_height, color_space);
       if(!res)
       {
         // if the thumbnail is not large enough, we compute one
-        img2 = dt_image_cache_get(darktable.image_cache, imgid, 'r');
+        const dt_image_t *img2 = dt_image_cache_get(darktable.image_cache, imgid, 'r');
         const int imgwd = img2->width;
         const int imght = img2->height;
         dt_image_cache_read_release(darktable.image_cache, img2);
diff --git a/src/common/styles.c b/src/common/styles.c
index 777fe86d22dc..b72ecdea934d 100644
--- a/src/common/styles.c
+++ b/src/common/styles.c
@@ -756,6 +756,7 @@ void dt_styles_apply_to_image(const char *name, gboolean duplicate, int32_t imgi
 
     /* remove old obsolete thumbnails */
     dt_mipmap_cache_remove(darktable.mipmap_cache, newimgid);
+    dt_image_reset_final_size(newimgid);
 
     /* if we have created a duplicate, reset collected images */
     if(duplicate) dt_control_signal_raise(darktable.signals, DT_SIGNAL_COLLECTION_CHANGED);
diff --git a/src/external/rawspeed b/src/external/rawspeed
index 521c6c6b763b..e30e3ead932a 160000
--- a/src/external/rawspeed
+++ b/src/external/rawspeed
@@ -1 +1 @@
-Subproject commit 521c6c6b763bed22ed1d4ad12ba224b1f39d29e2
+Subproject commit e30e3ead932a27871a3d16ec70d2ab395556f322
diff --git a/src/views/darkroom.c b/src/views/darkroom.c
index 2133ef531493..19c89e422ff4 100644
--- a/src/views/darkroom.c
+++ b/src/views/darkroom.c
@@ -615,6 +615,7 @@ static void dt_dev_change_image(dt_develop_t *dev, const uint32_t imgid)
   // if()
   {
     dt_mipmap_cache_remove(darktable.mipmap_cache, dev->image_storage.id);
+    dt_image_reset_final_size(dev->image_storage.id);
     dt_image_synch_xmp(dev->image_storage.id);
   }
 
@@ -2517,6 +2518,7 @@ void leave(dt_view_t *self)
   // if()
   {
     dt_mipmap_cache_remove(darktable.mipmap_cache, dev->image_storage.id);
+    dt_image_reset_final_size(dev->image_storage.id);
     // dump new xmp data
     dt_image_synch_xmp(dev->image_storage.id);
   }
diff --git a/src/views/lighttable.c b/src/views/lighttable.c
index f89a676f7b5d..32627d36711f 100644
--- a/src/views/lighttable.c
+++ b/src/views/lighttable.c
@@ -353,7 +353,7 @@ static inline void _destroy_preview_surface(dt_preview_surface_t *fp_surf)
   fp_surf->imgid = -1;
   fp_surf->w_lock = 0;
 
-  fp_surf->zoom_100 = 40.0f;
+  fp_surf->zoom_100 = 1001.0f; // dummy vaule to say it need recompute
   fp_surf->w_fit = 0.0f;
   fp_surf->h_fit = 0.0f;
 
@@ -1790,6 +1790,18 @@ static int expose_zoomable(dt_view_t *self, cairo_t *cr, int32_t width, int32_t
   return missing;
 }
 
+static float _preview_get_zoom100(int32_t width, int32_t height, uint32_t imgid)
+{
+  int w, h;
+  w = h = 0;
+  dt_image_get_final_size(imgid, &w, &h);
+  // 0.97f value come from dt_view_image_expose
+  float zoom_100 = fmaxf((float)w / ((float)width * 0.97f), (float)h / ((float)height * 0.97f));
+  if(zoom_100 < 1.0f) zoom_100 = 1.0f;
+
+  return zoom_100;
+}
+
 static int expose_expose(dt_view_t *self, cairo_t *cr, int32_t width, int32_t height, int32_t pointerx,
                          int32_t pointery, const dt_lighttable_layout_t layout)
 {
@@ -2131,7 +2143,9 @@ static int expose_expose(dt_view_t *self, cairo_t *cr, int32_t width, int32_t he
       params.full_surface_wd = &lib->fp_surf[i].width;
       params.full_surface_ht = &lib->fp_surf[i].height;
       params.full_surface_w_lock = &lib->fp_surf[i].w_lock;
-      params.full_zoom100 = &lib->fp_surf[i].zoom_100;
+      if(lib->fp_surf[i].zoom_100 >= 1000.0f || lib->fp_surf[i].imgid != images[i].imgid)
+        lib->fp_surf[i].zoom_100 = _preview_get_zoom100(images[i].width, images[i].height, images[i].imgid);
+      params.full_zoom100 = lib->fp_surf[i].zoom_100;
       params.full_w1 = &lib->fp_surf[i].w_fit;
       params.full_h1 = &lib->fp_surf[i].h_fit;
       params.full_maxdx = &lib->fp_surf[i].max_dx;
@@ -2306,7 +2320,9 @@ static int expose_full_preview(dt_view_t *self, cairo_t *cr, int32_t width, int3
   params.zoom = 1;
   params.full_preview = TRUE;
   params.full_zoom = lib->full_zoom;
-  params.full_zoom100 = &lib->fp_surf[0].zoom_100;
+  if(lib->fp_surf[0].zoom_100 >= 1000.0f || lib->fp_surf[0].imgid != lib->full_preview_id)
+    lib->fp_surf[0].zoom_100 = _preview_get_zoom100(width, height, lib->full_preview_id);
+  params.full_zoom100 = lib->fp_surf[0].zoom_100;
   params.full_maxdx = &lib->fp_surf[0].max_dx;
   params.full_maxdy = &lib->fp_surf[0].max_dy;
   params.full_w1 = &lib->fp_surf[0].w_fit;
diff --git a/src/views/view.c b/src/views/view.c
index 6dcda1e70f22..6360c2127699 100644
--- a/src/views/view.c
+++ b/src/views/view.c
@@ -1095,11 +1095,9 @@ int dt_view_image_expose(dt_view_image_expose_t *vals)
 
 
   dt_mipmap_cache_t *cache = darktable.mipmap_cache;
-  if(vals->full_surface_id && vals->full_zoom100 && *(vals->full_surface_id) != imgid)
-    *(vals->full_zoom100) = 40.0f;
   float fz = 1.0f;
   if(full_zoom > 0.0f) fz = full_zoom;
-  if(vals->full_zoom100 && *(vals->full_zoom100) > 0.0f) fz = fminf(*(vals->full_zoom100), fz);
+  if(vals->full_zoom100 > 0.0f) fz = fminf(vals->full_zoom100, fz);
   dt_mipmap_size_t mip = dt_mipmap_cache_get_matching_size(cache, imgwd * width * fz, imgwd * height * fz);
 
 
@@ -1139,21 +1137,6 @@ int dt_view_image_expose(dt_view_image_expose_t *vals)
     buf_wd = *(vals->full_surface_wd);
     buf_ht = *(vals->full_surface_ht);
   }
-  // we want to sanitize full_zoom value to be sure not to exceed 100%
-  if(fz > 1.0f && buf_sizeok)
-  {
-    // is the mipmap loaded the full one ?
-    if(cache->max_width[mip] > buf_wd + 4 && cache->max_height[mip] > buf_ht + 4)
-    {
-      float zoom_100 = fmaxf((float)buf_wd / ((float)width * imgwd), (float)buf_ht / ((float)height * imgwd));
-      if(zoom_100 < 1.0f) zoom_100 = 1.0f;
-      if(vals->full_zoom100) *(vals->full_zoom100) = zoom_100;
-      if(fz > zoom_100)
-      {
-        fz = zoom_100;
-      }
-    }
-  }
 
   if(draw_thumb_background)
   {
diff --git a/src/views/view.h b/src/views/view.h
index 11722ed04428..4849eb5ed293 100644
--- a/src/views/view.h
+++ b/src/views/view.h
@@ -167,7 +167,7 @@ typedef struct dt_view_image_expose_t
   gboolean full_preview;
   gboolean image_only;
   float full_zoom;
-  float *full_zoom100;
+  float full_zoom100;
   float *full_w1;
   float *full_h1;
   float full_x;