diff --git a/Firmware/xyzcal.cpp b/Firmware/xyzcal.cpp
index 4e55996a3..d68bfbc1a 100644
--- a/Firmware/xyzcal.cpp
+++ b/Firmware/xyzcal.cpp
@@ -426,8 +426,41 @@ void go_and_stop(uint8_t axis, int16_t dec, uint16_t &delay_us, uint16_t &steps)
 	--steps;
 }
 
+/// Count number of zeros on the 32 byte array
+/// If the number is less than 16, it changes @min_z so it will be next time
+bool more_zeros(uint8_t* pixels, int16_t &min_z){
+	uint8_t hist[256];
+	uint8_t i = 0;
+	
+	/// clear
+	do {
+		hist[i] = 0;
+	} while (i++ < 255);
+
+	/// fill
+	for (i = 0; i < 32; ++i){
+		++hist[pixels[i]];
+	}
+	
+	/// already more zeros on the line
+	if (hist[0] >= 16)
+		return true;
+	
+	/// find threshold
+	uint8_t sum = 0;
+	i = 0;
+	do {
+		sum += hist[i];
+		if (sum >= 16)
+			break;
+	} while (i++ < 255);
+
+	min_z += i;
+	return false;
+}
+
 void xyzcal_scan_pixels_32x32_Zhop(int16_t cx, int16_t cy, int16_t min_z, int16_t max_z, uint16_t delay_us, uint8_t* pixels){
-	if(!pixels)
+	if (!pixels)
 		return;
 	int16_t z = _Z;
 	int16_t z_trig;
@@ -436,109 +469,121 @@ void xyzcal_scan_pixels_32x32_Zhop(int16_t cx, int16_t cy, int16_t min_z, int16_
 	xyzcal_lineXYZ_to(cx - 1024, cy - 1024, min_z, delay_us, 0);
 	int16_t start_z;
 	uint16_t steps_to_go;
+	uint8_t restart = 0; ///< restart if needed but just once
+	int16_t corr_min_z = min_z; ///< shifted min_z if it's too low
 
-	for (uint8_t r = 0; r < 32; r++){ ///< Y axis
-		xyzcal_lineXYZ_to(_X, cy - 1024 + r * 64, z, delay_us, 0);
-		for (int8_t d = 0; d < 2; ++d){ ///< direction			
-			xyzcal_lineXYZ_to((d & 1) ? (cx + 1024) : (cx - 1024), _Y, min_z, delay_us, 0);
+	do {
+		if (restart == 1)
+			restart = 2;
+		for (uint8_t r = 0; r < 32; r++){ ///< Y axis
+			xyzcal_lineXYZ_to(_X, cy - 1024 + r * 64, z, delay_us, 0);
+			for (int8_t d = 0; d < 2; ++d){ ///< direction			
+				xyzcal_lineXYZ_to((d & 1) ? (cx + 1024) : (cx - 1024), _Y, corr_min_z, delay_us, 0);
 
-			z = _Z;
-			sm4_set_dir(X_AXIS, d);
-			for (uint8_t c = 0; c < 32; c++){ ///< X axis
+				z = _Z;
+				sm4_set_dir(X_AXIS, d);
+				for (uint8_t c = 0; c < 32; c++){ ///< X axis
 
-				z_trig = min_z;
+					z_trig = corr_min_z;
 
-				/// move up to un-trigger (surpress hysteresis)
-				sm4_set_dir(Z_AXIS, Z_PLUS);
-				/// speed up from stop, go half the way
-				current_delay_us = MAX_DELAY;
-				for (start_z = z; z < (max_z + start_z) / 2; ++z){
-					if (!_PINDA){
-						break;
+					/// move up to un-trigger (surpress hysteresis)
+					sm4_set_dir(Z_AXIS, Z_PLUS);
+					/// speed up from stop, go half the way
+					current_delay_us = MAX_DELAY;
+					for (start_z = z; z < (max_z + start_z) / 2; ++z){
+						if (!_PINDA){
+							break;
+						}
+						accelerate(Z_AXIS_MASK, Z_ACCEL, current_delay_us, Z_MIN_DELAY);
 					}
-					accelerate(Z_AXIS_MASK, Z_ACCEL, current_delay_us, Z_MIN_DELAY);
-				}
 
-				if(_PINDA){
-					uint16_t steps_to_go = MAX(0, max_z - z);
-					while (_PINDA && z < max_z){
-						go_and_stop(Z_AXIS_MASK, Z_ACCEL, current_delay_us, steps_to_go);
+					if(_PINDA){
+						uint16_t steps_to_go = MAX(0, max_z - z);
+						while (_PINDA && z < max_z){
+							go_and_stop(Z_AXIS_MASK, Z_ACCEL, current_delay_us, steps_to_go);
+							++z;
+						}
+					}
+					/// slow down to stop
+					while (current_delay_us < MAX_DELAY){
+						accelerate(Z_AXIS_MASK, -Z_ACCEL, current_delay_us, Z_MIN_DELAY);
 						++z;
 					}
-				}
-				/// slow down to stop
-				while (current_delay_us < MAX_DELAY){
-					accelerate(Z_AXIS_MASK, -Z_ACCEL, current_delay_us, Z_MIN_DELAY);
-					++z;
-				}
 
-				/// move down to trigger
-				sm4_set_dir(Z_AXIS, Z_MINUS);
-				/// speed up
-				current_delay_us = MAX_DELAY;
-				for (start_z = z; z > (min_z + start_z) / 2; --z){
-					if (_PINDA){
-						z_trig = z;
-						break;
+					/// move down to trigger
+					sm4_set_dir(Z_AXIS, Z_MINUS);
+					/// speed up
+					current_delay_us = MAX_DELAY;
+					for (start_z = z; z > (corr_min_z + start_z) / 2; --z){
+						if (_PINDA){
+							z_trig = z;
+							break;
+						}
+						accelerate(Z_AXIS_MASK, Z_ACCEL, current_delay_us, Z_MIN_DELAY);
 					}
-					accelerate(Z_AXIS_MASK, Z_ACCEL, current_delay_us, Z_MIN_DELAY);
-				}
-				/// slow down
-				if(!_PINDA){
-					steps_to_go = MAX(0, z - min_z);
-					while (!_PINDA && z > min_z){
-						go_and_stop(Z_AXIS_MASK, Z_ACCEL, current_delay_us, steps_to_go);
+					/// slow down
+					if(!_PINDA){
+						steps_to_go = MAX(0, z - corr_min_z);
+						while (!_PINDA && z > corr_min_z){
+							go_and_stop(Z_AXIS_MASK, Z_ACCEL, current_delay_us, steps_to_go);
+							--z;
+						}
+						z_trig = z;
+					}
+					/// slow down to stop
+					while (z > corr_min_z && current_delay_us < MAX_DELAY){
+						accelerate(Z_AXIS_MASK, -Z_ACCEL, current_delay_us, Z_MIN_DELAY);
 						--z;
 					}
-					z_trig = z;
-				}
-				/// slow down to stop
-				while (z > min_z && current_delay_us < MAX_DELAY){
-					accelerate(Z_AXIS_MASK, -Z_ACCEL, current_delay_us, Z_MIN_DELAY);
-					--z;
-				}
 
-				count_position[2] = z;
-				if (d == 0){
-					line_buffer[c] = (uint16_t)(z_trig - min_z);
-				} else {
-					/// data reversed in X
-					// DBG(_n("%04x"), (line_buffer[31 - c] + (z - min_z)) / 2);
-					/// save average of both directions
-					pixels[(uint16_t)r * 32 + (31 - c)] = (uint8_t)MIN((uint32_t)255, ((uint32_t)line_buffer[31 - c] + (z_trig - min_z)) / 2);
-				}
+					count_position[2] = z;
+					if (d == 0){
+						line_buffer[c] = (uint16_t)(z_trig - corr_min_z);
+					} else {
+						/// data reversed in X
+						// DBG(_n("%04x"), (line_buffer[31 - c] + (z - corr_min_z)) / 2);
+						/// save average of both directions
+						pixels[(uint16_t)r * 32 + (31 - c)] = (uint8_t)MIN((uint32_t)255, ((uint32_t)line_buffer[31 - c] + (z_trig - corr_min_z)) / 2);
+					}
 
-				/// move to the next point and move Z up diagonally (if needed)
-				current_delay_us = MAX_DELAY;
-				// const int8_t dir = (d & 1) ? -1 : 1;
-				const int16_t end_x = ((d & 1) ? 1 : -1) * (64 * (16 - c) - 32) + cx;
-				const int16_t length_x = ABS(end_x - _X);
-				const int16_t half_x = length_x / 2;
-				int16_t x = 0;
-				/// don't go up if PINDA not triggered
-				const bool up = _PINDA;
-				int8_t axis = up ? X_AXIS_MASK | Z_AXIS_MASK : X_AXIS_MASK;
+					/// move to the next point and move Z up diagonally (if needed)
+					current_delay_us = MAX_DELAY;
+					// const int8_t dir = (d & 1) ? -1 : 1;
+					const int16_t end_x = ((d & 1) ? 1 : -1) * (64 * (16 - c) - 32) + cx;
+					const int16_t length_x = ABS(end_x - _X);
+					const int16_t half_x = length_x / 2;
+					int16_t x = 0;
+					/// don't go up if PINDA not triggered
+					const bool up = _PINDA;
+					int8_t axis = up ? X_AXIS_MASK | Z_AXIS_MASK : X_AXIS_MASK;
 
-				sm4_set_dir(Z_AXIS, Z_PLUS);
-				/// speed up
-				for (x = 0; x <= half_x; ++x){
-					accelerate(axis, Z_ACCEL, current_delay_us, Z_MIN_DELAY);
-					if (up)
-						++z;
+					sm4_set_dir(Z_AXIS, Z_PLUS);
+					/// speed up
+					for (x = 0; x <= half_x; ++x){
+						accelerate(axis, Z_ACCEL, current_delay_us, Z_MIN_DELAY);
+						if (up)
+							++z;
+					}
+					/// slow down
+					steps_to_go = length_x - x;
+					for (; x < length_x; ++x){
+						go_and_stop(axis, Z_ACCEL, current_delay_us, steps_to_go);
+						if (up)
+							++z;
+					}
+					count_position[0] = end_x;
+					count_position[2] = z;
 				}
-				/// slow down
-				steps_to_go = length_x - x;
-				for (; x < length_x; ++x){
-					go_and_stop(axis, Z_ACCEL, current_delay_us, steps_to_go);
-					if (up)
-						++z;
-				}
-				count_position[0] = end_x;
-				count_position[2] = z;
 			}
+			if (r == 0 && restart == 0){
+				if (!more_zeros(pixels, corr_min_z))
+					restart = 1;
+			}
+			if (restart == 1)
+				break;
+			// DBG(_n("\n\n"));
 		}
-		// DBG(_n("\n\n"));
-	}
+	} while (restart == 1);
 }
 
 /// Returns rate of match