diff --git a/larndsim/config/config.yaml b/larndsim/config/config.yaml
index b3947fcc..e9fc0546 100644
--- a/larndsim/config/config.yaml
+++ b/larndsim/config/config.yaml
@@ -57,6 +57,11 @@ module0:
     LIGHT_LUT_ID:    [0, 1, 1, 1]
     MOD2MOD_VARIATION: True
 
+2x2_lut_fp16:
+    <<: *2x2modvar
+    LIGHT_LUT:       [/dvs_ro/cfs/cdirs/dune/www/data/2x2/simulation/larndsim_data/light_LUT/lightLUT_Mod0_06052024_time_norm_swapped_y_fp16.npz, /dvs_ro/cfs/cdirs/dune/www/data/2x2/simulation/larndsim_data/light_LUT/lightLUT_Mod123_06052024_time_norm_swapped_y_fp16.npz]
+    LIGHT_LUT_ID:    [0, 1, 1, 1]
+
 # 2x2 (differnt module configuration), single pixel threshold (defined in detector property)
 2x2_single_threshold:
     <<: *2x2modvar
@@ -82,14 +87,19 @@ ndlar: &ndlarmain
     LIGHT_DET_NOISE: 4Mod_LNoise_Mod1_2fftx192_MR5-ish.npy
     LIGHT_SIMULATED: False
     MOD2MOD_VARIATION: True
-
+    
+ndlar_mpvmpr:
+    <<: *ndlarmain
+    SIM_PROPERTIES: singles_sim_ndlar.yaml
+    
 ndlar_light:
     <<: *ndlarmain
     LIGHT_SIMULATED: True
 
-ndlar_mpvmpr:
+ndlar_light_lut_fp16:
     <<: *ndlarmain
-    SIM_PROPERTIES: singles_sim_ndlar.yaml
+    LIGHT_LUT: /dvs_ro/cfs/cdirs/dune/www/data/2x2/simulation/larndsim_data/light_LUT/lightLUT_FSD_250123_time_norm_fp16.npz
+    LIGHT_SIMULATED: True
 
 fsd:
     SIM_PROPERTIES:  cosmic_sim.yaml
@@ -104,3 +114,7 @@ fsd:
     LIGHT_LUT:       /dvs_ro/cfs/cdirs/dune/www/data/2x2/simulation/larndsim_data/light_LUT/lightLUT_FSD_250123_time_norm.npz
     LIGHT_DET_NOISE: FSD_v01_bin06_larndsim_noise.npy
     LIGHT_SIMULATED: True
+
+fsd_lut_fp16:
+    <<: *fsd
+    LIGHT_LUT: /dvs_ro/cfs/cdirs/dune/www/data/2x2/simulation/larndsim_data/light_LUT/lightLUT_FSD_250123_time_norm_fp16.npz
diff --git a/larndsim/light_sim.py b/larndsim/light_sim.py
index 7c166918..162747fc 100644
--- a/larndsim/light_sim.py
+++ b/larndsim/light_sim.py
@@ -6,6 +6,7 @@
 import numba as nb
 
 from numba import cuda
+from numba import float32
 
 import numpy as np
 import cupy as cp
@@ -100,7 +101,7 @@ def sum_light_signals(segments, segment_voxel, segment_track_id, light_inc, op_c
                         for iprof in range(time_profile.shape[0]):
                             profile_time = track_time + iprof * units.ns / units.mus # FIXME: assumes light LUT time profile bins are 1ns (might not be true in general)
                             if profile_time < end_tick_time and profile_time > start_tick_time:
-                                photons = light_inc['n_photons_det'][itrk,op_channel[idet]] * time_profile[iprof] / light.LIGHT_TICK_SIZE
+                                photons = light_inc['n_photons_det'][itrk,op_channel[idet]] * float32(time_profile[iprof]) / light.LIGHT_TICK_SIZE
                                 light_sample_inc[idet,itick] += photons
 
                                 if photons > sim.MC_TRUTH_THRESHOLD: