diff -r 02d771ecb347 platform/5D3.113/features.h
--- a/platform/5D3.113/features.h	Sat Oct 12 09:19:57 2013 +0300
+++ b/platform/5D3.113/features.h	Mon Oct 14 09:58:07 2013 +0300
@@ -24,3 +24,5 @@
 #undef FEATURE_VOICE_TAGS // No sound recorded
 
 #define FEATURE_LV_FOCUS_BOX_SNAP_TO_X5_RAW
+
+#define FEATURE_ELECTRONIC_LEVEL_LOGGING
diff -r 02d771ecb347 platform/5D3.113/include/platform/state-object.h
--- a/platform/5D3.113/include/platform/state-object.h	Sat Oct 12 09:19:57 2013 +0300
+++ b/platform/5D3.113/include/platform/state-object.h	Mon Oct 14 09:58:07 2013 +0300
@@ -7,4 +7,6 @@
 #define MOVREC_STATE (*(struct state_object **)0x27850)
 #define SSS_STATE (*(struct state_object **)0x25E44)
 
+#define SCS_STATE (*(struct state_object **)0x25284)
+
 #endif // __platform_state_object_h
diff -r 02d771ecb347 src/shoot.c
--- a/src/shoot.c	Sat Oct 12 09:19:57 2013 +0300
+++ b/src/shoot.c	Mon Oct 14 09:58:07 2013 +0300
@@ -54,6 +54,10 @@
 static CONFIG_INT("post.deflicker.level", post_deflicker_target_level, -4);
 #endif
 
+#ifdef FEATURE_ELECTRONIC_LEVEL_LOGGING
+static CONFIG_INT("electronic.level.log", electronic_level_log, 0);
+#endif
+
 void move_lv_afframe(int dx, int dy);
 void movie_start();
 void movie_end();
@@ -3780,6 +3784,17 @@
         },
     },
     #endif
+    
+    #ifdef FEATURE_ELECTRONIC_LEVEL_LOGGING
+    {
+        .name = "Post Rotate", 
+        .priv = &electronic_level_log, 
+        .max = 1,
+        .help  = "Save orientation (roll/pitch angle) in a sidecar file,",
+        .help2 = "so you can rotate the picture in post automatically.",
+        .works_best_in = DEP_PHOTO_MODE,
+    },
+    #endif
 
     #ifdef FEATURE_BULB_TIMER
     {
@@ -5631,6 +5646,168 @@
 }
 #endif
 
+#ifdef FEATURE_ELECTRONIC_LEVEL_LOGGING
+static volatile int roll;
+static volatile int pitch;
+static volatile int roll_pitch_status = 1;
+static volatile int roll_pitch_timestamp = 0;
+static struct msg_queue * level_mq = 0;
+
+static void level_mq_init()
+{
+    level_mq = (void*) msg_queue_create("level_mq", 100);
+}
+
+INIT_FUNC("level_mq", level_mq_init);
+
+struct rolling_pitching
+{
+    uint8_t status;
+    uint8_t cameraposture;
+    uint8_t roll_hi;
+    uint8_t roll_lo;
+    uint8_t pitch_hi;
+    uint8_t pitch_lo;
+};
+
+PROP_HANDLER(PROP_ROLLING_PITCHING_LEVEL)
+{
+    struct rolling_pitching * orientation = (struct rolling_pitching *) buf;
+    
+    static int first_time = 1;
+    if (!first_time)
+        roll_pitch_status = orientation->status;
+    first_time = 0;
+
+    if (orientation->status == 2)
+    {
+        roll = orientation->roll_hi * 256 + orientation->roll_lo;
+        pitch = orientation->pitch_hi * 256 + orientation->pitch_lo;
+        
+        /* so we know whether the values are still valid */
+        roll_pitch_timestamp = get_ms_clock_value();
+    }
+}
+
+static char electronic_level_last_msg[100];
+
+static void electronic_level_save_sidecar_file_for_cr2(int file_number, int roll, int pitch)
+{
+    /* prefer -180.00 ... +180.00 range instead of 0.00 ... 360.00 */
+    if (roll > 18000)  roll  -= 36000;
+    if (pitch > 18000) pitch -= 36000;
+
+    char fn[100];
+    snprintf(fn, sizeof(fn), "%s/%s%04d.LEV", get_dcim_dir(), get_file_prefix(), file_number);
+    FILE* f = FIO_CreateFileEx(fn);
+    if (f == INVALID_PTR) return;
+    snprintf(electronic_level_last_msg, sizeof(electronic_level_last_msg), 
+        "Roll  : %s%d.%02d\n"
+        "Pitch : %s%d.%02d\n",
+        FMT_FIXEDPOINT2S(roll),
+        FMT_FIXEDPOINT2S(pitch)
+    );
+    my_fprintf(f, electronic_level_last_msg);
+    FIO_CloseFile(f);
+}
+
+static void electronic_level_sidecar_task()
+{
+    /* the trigger is a bit too early */
+    /* trial and error, rotate the camera at constant speed while taking a burst speed;
+     * adjust it until the systematic error disappears
+     */
+    msleep(50);
+    
+    /* force an update */
+    roll_pitch_timestamp = 0;
+    int iter = 0;
+    while (roll_pitch_timestamp == 0)
+    {
+        msleep(10);
+        iter++;
+        if (iter > 100)
+        {
+            /* something's wrong */
+            snprintf(electronic_level_last_msg, sizeof(electronic_level_last_msg), 
+                "Roll / pitch\nnot updated."
+            );
+            beep();
+            return;
+        }
+    }
+    
+    /* check sync (long exposures are best for this) */
+    /* should trigger at the start of exposure */
+    //~ beep();
+    
+    /* put roll/pitch data into a message queue, for syncing with the files */
+    msg_queue_post(level_mq, ((uint32_t)roll & 0xFFFF) | ((uint32_t)pitch << 16));
+}
+
+/* called from QR zebras */
+void electronic_level_sidecar_show_info()
+{
+    if (electronic_level_log && electronic_level_last_msg[0])
+    {
+        bmp_printf(FONT_MED, 300, os.y_max - font_med.height * 2, electronic_level_last_msg);
+        electronic_level_last_msg[0] = 0;
+    }
+}
+
+/* called from SCS task, at the start of exposure */
+void electronic_level_sidecar_trigger()
+{
+    if (electronic_level_log)
+    {
+        /* not a really good idea to slow down Canon picture taking task */
+        task_create("level_task", 0x1c, 0x1000, electronic_level_sidecar_task, (void*) 0);
+    }
+}
+
+static void electronic_level_sidecar_save_task(void* file_number)
+{
+   if (level_mq == 0) return;
+    uint32_t msg;
+    int err = msg_queue_receive(level_mq, (struct event**)&msg, 1000);
+    if (err == 0)
+    {
+        uint32_t roll = msg & 0xFFFF;
+        uint32_t pitch = msg >> 16;
+        electronic_level_save_sidecar_file_for_cr2((int)file_number, roll, pitch);
+    }
+    else
+    {
+        console_printf("%d: recv err\n", file_number);
+    }
+}
+
+PROP_HANDLER(PROP_FILE_NUMBER_A)
+{
+    static int prev_file = -1;
+    int file = buf[0];
+    
+    if (electronic_level_log && prev_file != file && prev_file != -1)
+    {
+        /* new CR2 file saved? get a measurement from the queue and save it to sidecar file */
+        /* not a good idea to slow down the property task */
+        task_create("level_save_task", 0x1c, 0x1000, electronic_level_sidecar_save_task, (void*) file);
+    }
+    prev_file = file;
+}
+
+/* periodical check whether electronic level is still active */
+static void electronic_level_refresh()
+{
+    if (electronic_level_log && roll_pitch_status == 1)
+    {
+        GUI_SetRollingPitchingLevelStatus(0);
+        msleep(100);
+    }
+}
+
+#endif
+
 static struct msg_queue * shoot_task_mqueue = NULL;
 
 /* cause an immediate redraw of the shooting task infos. not used yet, but can be triggered by model-specific code */
@@ -5762,6 +5939,10 @@
         module_exec_cbr(CBR_SHOOT_TASK);
 #endif
 
+#ifdef FEATURE_ELECTRONIC_LEVEL_LOGGING
+        electronic_level_refresh();
+#endif
+
         #ifdef FEATURE_MLU_HANDHELD_DEBUG
         if (mlu_handled_debug) big_bmp_printf(FONT_MED, 50, 100, "%s", mlu_msg);
         #endif
diff -r 02d771ecb347 src/state-object.c
--- a/src/state-object.c	Sat Oct 12 09:19:57 2013 +0300
+++ b/src/state-object.c	Mon Oct 14 09:58:07 2013 +0300
@@ -281,6 +281,24 @@
 }
 #endif
 
+#ifdef SCS_STATE
+static int stateobj_scs_spy(struct state_object * self, int x, int input, int z, int t)
+{
+    int old_state = self->current_state;
+    int ans = StateTransition(self, x, input, z, t);
+    int new_state = self->current_state;
+
+    #if defined(CONFIG_5D3)
+    #ifdef FEATURE_ELECTRONIC_LEVEL_LOGGING
+    if (old_state == 8 && input == 5 && (new_state == 9 || new_state == 12)) // scsReleaseStart
+        electronic_level_sidecar_trigger();
+    #endif
+    #endif
+
+    return ans;
+}
+#endif
+
 static int stateobj_start_spy(struct state_object * stateobj, void* spy)
 {
     if (!StateTransition)
@@ -323,6 +341,10 @@
     #ifdef SDS_FRONT3_STATE
         stateobj_start_spy(SDS_FRONT3_STATE, stateobj_sdsf3_spy);
     #endif
+
+    #ifdef SCS_STATE
+        stateobj_start_spy(SCS_STATE, stateobj_scs_spy);
+    #endif
     
     #ifdef CONFIG_550D
     display_is_on_550D = (DISPLAY_STATEOBJ->current_state != 0);
diff -r 02d771ecb347 src/zebra.c
--- a/src/zebra.c	Sat Oct 12 09:19:57 2013 +0300
+++ b/src/zebra.c	Mon Oct 14 09:58:07 2013 +0300
@@ -4131,6 +4131,10 @@
     bvram_mirror_clear(); // may be filled with liveview cropmark / masking info, not needed in play mode
     clrscr();
 
+    #ifdef FEATURE_ELECTRONIC_LEVEL_LOGGING
+    electronic_level_sidecar_show_info();
+    #endif
+
     #ifdef FEATURE_CROPMARKS
     cropmark_redraw();
     #endif