diff --git a/shared/V210.hpp b/shared/V210.hpp
index 3503041..f4ee4e8 100644
--- a/shared/V210.hpp
+++ b/shared/V210.hpp
@@ -20,6 +20,24 @@ constexpr std::array<Color, 7> SMPTE_BARS = {{
     {111, 848, 481},  // blue
 }};
 
+// IRE 11-step greyscale bars
+// from total black to 100% white
+// Y_10bit = 64 + (IRE / 100) × (940 − 64) Rec. 709/Rec. 2020
+// Y_10bit = 64 + (IRE × 8.76)
+constexpr std::array<Color, 11> IRE_BARS = {{
+    {64, 512, 512},  // IRE 0
+    {152, 512, 512}, // IRE 10
+    {239, 512, 512}, // IRE 20 and so on
+    {327, 512, 512},
+    {414, 512, 512},
+    {502, 512, 512},
+    {590, 512, 512},
+    {677, 512, 512},
+    {765, 512, 512},
+    {852, 512, 512},
+    {940, 512, 512},
+}};
+
 // Pack 6 pixels into 4 x 32-bit V210 words (16 bytes total).
 //
 // V210 is 4:2:2 — each pair of pixels shares one Cb and one Cr sample.
@@ -41,7 +59,7 @@ inline void pack_block(
     w[3] = (y4     & 0x3FFu)        | ((p45.cr & 0x3FFu) << 10) | ((y5     & 0x3FFu) << 20);
 }
 
-// Write one horizontal line of SMPTE 75% bars.
+// Write one horizontal line of bars.
 // `stride` is the line size in bytes as returned by MXL (configInfo.discrete.sliceSizes[0]).
 // Bytes beyond the active pixels are already zeroed by the mmap, so no explicit padding needed.
 inline void write_bar_line(uint8_t* line, int width, uint32_t /*stride*/)
@@ -64,7 +82,7 @@ inline void write_bar_line(uint8_t* line, int width, uint32_t /*stride*/)
     }
 }
 
-// Fill an entire frame buffer with SMPTE 75% color bars.
+// Fill an entire frame buffer with color bars.
 inline void fill_frame(uint8_t* buf, int width, int height, uint32_t stride)
 {
     for (int y = 0; y < height; y++) {