diff --git a/cuburn/code/filtering.py b/cuburn/code/filtering.py
index bd1ae73..8746090 100644
--- a/cuburn/code/filtering.py
+++ b/cuburn/code/filtering.py
@@ -4,8 +4,10 @@ from cuburn.code.util import *
 class ColorClip(HunkOCode):
     defs = """
 __global__
-void colorclip(float4 *pixbuf, float gamma, float vibrancy, float highpow) {
-    // TODO: test if over an edge of the framebuffer
+void colorclip(float4 *pixbuf, float gamma, float vibrancy, float highpow,
+               float linrange, float lingam) {
+    // TODO: test if over an edge of the framebuffer - currently gutters are
+    // used and up to 256 pixels are ignored, which breaks when width<256
     int i = blockDim.x * blockIdx.x + threadIdx.x;
     float4 pix = pixbuf[i];
 
@@ -13,8 +15,12 @@ void colorclip(float4 *pixbuf, float gamma, float vibrancy, float highpow) {
 
     float4 opix = pix;
 
-    // TODO: linearized bottom range
-    float alpha = powf(pix.w, gamma);
+    float alpha = pow(pix.w, gamma);
+    if (pix.w < linrange) {
+        float frac = pix.w / linrange;
+        alpha = (1.0f - frac) * pix.w * lingam / linrange + frac * alpha;
+    }
+
     float ls = vibrancy * alpha / pix.w;
 
     float maxc = fmaxf(pix.x, fmaxf(pix.y, pix.z));
diff --git a/cuburn/render.py b/cuburn/render.py
index 351315c..feea1fb 100644
--- a/cuburn/render.py
+++ b/cuburn/render.py
@@ -308,16 +308,18 @@ class _AnimRenderer(object):
                      self.stream)
         self.stream.synchronize()
 
-
-        n = np.float32(self.ncps)
-        gam = np.float32(n / gam)
-        vib = np.float32(vib / n)
-        hipow = np.float32(hipow / n)
+        f = np.float32
+        n = f(self.ncps)
+        gam = f(n / gam)
+        vib = f(vib / n)
+        hipow = f(hipow / n)
+        lin = f(cen_cp.gam_lin_thresh)
+        lingam = f(math.pow(cen_cp.gam_lin_thresh, gam))
 
         # TODO: get block size from colorclip class? It actually does not
         # depend on that being the case
         color_fun = a.mod.get_function("colorclip")
-        color_fun(self.d_out, gam, vib, hipow,
+        color_fun(self.d_out, gam, vib, hipow, lin, lingam,
                   block=(256, 1, 1), grid=(self.nbins / 256, 1),
                   stream=self.stream)