diff --git a/stuff/config/current.txt b/stuff/config/current.txt
index cb1f02a..9d28339 100644
--- a/stuff/config/current.txt
+++ b/stuff/config/current.txt
@@ -405,6 +405,7 @@
   <item>"STD_solarizeFx.peak_edge"	"Peak Edge"	</item>
 
   <item>"STD_spiralFx"		"Spiral"		</item>
+  <item>"STD_spiralFx.type"		"Type"	</item>
   <item>"STD_spiralFx.freq"		"Frequency"	</item>
   <item>"STD_spiralFx.phase"	"Phase"		</item>
   <item>"STD_spiralFx.colors"	"Colors"		</item>
diff --git a/stuff/profiles/layouts/fxs/STD_spiralFx.xml b/stuff/profiles/layouts/fxs/STD_spiralFx.xml
index 49a0571..5deef61 100644
--- a/stuff/profiles/layouts/fxs/STD_spiralFx.xml
+++ b/stuff/profiles/layouts/fxs/STD_spiralFx.xml
@@ -1,5 +1,6 @@
 <fxlayout>
   <page name="Spiral">
+    <control>type</control>
     <control>colors</control>
     <control>freq</control>
     <control>phase</control>
diff --git a/toonz/sources/stdfx/stdfx.cpp b/toonz/sources/stdfx/stdfx.cpp
index 1183754..163d1da 100644
--- a/toonz/sources/stdfx/stdfx.cpp
+++ b/toonz/sources/stdfx/stdfx.cpp
@@ -69,13 +69,17 @@ public:
 
 class SpiralFx final : public TStandardZeraryFx {
   FX_PLUGIN_DECLARATION(SpiralFx)
+  TIntEnumParamP m_type;
   TDoubleParamP m_freq;
   TDoubleParamP m_phase;
   TSpectrumParamP m_spectrum;
 
+  enum SpiralType { Archimedean, Logarithmic };
+
 public:
   SpiralFx()
-      : m_freq(0.1)   // args, "Freq")
+      : m_type(new TIntEnumParam(Archimedean, "Archimedean"))
+      , m_freq(0.1)   // args, "Freq")
       , m_phase(0.0)  // args, "Phase")
   {
     // m_freq->setDefaultValue(0.1);
@@ -97,6 +101,8 @@ TPixel32 colors[] = {
         TSpectrum::ColorKey(1, transparent)};
     m_spectrum = TSpectrumParamP(colors);
 
+    m_type->addItem(Logarithmic, "Logarithmic");
+    bindParam(this, "type", m_type);
     bindParam(this, "colors", m_spectrum);
     bindParam(this, "freq", m_freq);
     bindParam(this, "phase", m_phase);
@@ -122,7 +128,8 @@ TPixel32 colors[] = {
 namespace {
 template <class T>
 void doComputeT(TRasterPT<T> raster, TPointD posTrasf, const TAffine &aff,
-                const TSpectrumT<T> &spectrum, double freq, double phase) {
+                const TSpectrumT<T> &spectrum, double freq, double phase,
+                bool isLogarithmic) {
   raster->lock();
   for (int y = 0; y < raster->getLy(); y++) {
     TPointD posAux = posTrasf;
@@ -131,6 +138,7 @@ void doComputeT(TRasterPT<T> raster, TPointD posTrasf, const TAffine &aff,
       double ang = 0.0;
       if (posAux.x != 0 || posAux.y != 0) ang = atan2(posAux.y, posAux.x);
       double r = sqrt(posAux.x * posAux.x + posAux.y * posAux.y);
+      if (isLogarithmic) r = std::log(r) * 30.0;
       double v = 0.5 * (1 + sin(r * freq + ang + phase));
       *pix++   = spectrum.getPremultipliedValue(v);
       posAux.x += aff.a11;
@@ -146,18 +154,19 @@ void doComputeT(TRasterPT<T> raster, TPointD posTrasf, const TAffine &aff,
 //==================================================================
 
 void SpiralFx::doCompute(TTile &tile, double frame, const TRenderSettings &ri) {
-  double phase = m_phase->getValue(frame);
-  double freq  = m_freq->getValue(frame);
+  double phase       = m_phase->getValue(frame);
+  double freq        = m_freq->getValue(frame);
+  bool isLogarithmic = SpiralType(m_type->getValue()) == Logarithmic;
 
   TAffine aff      = ri.m_affine.inv();
   TPointD posTrasf = aff * tile.m_pos;
 
   if (TRaster32P ras32 = tile.getRaster())
     doComputeT<TPixel32>(ras32, posTrasf, aff, m_spectrum->getValue(frame),
-                         freq, phase);
+                         freq, phase, isLogarithmic);
   else if (TRaster64P ras64 = tile.getRaster())
     doComputeT<TPixel64>(ras64, posTrasf, aff, m_spectrum->getValue64(frame),
-                         freq, phase);
+                         freq, phase, isLogarithmic);
   else
     throw TException("SpiralFx: unsupported Pixel Type");
 }