diff --git a/src/iterate.c b/src/iterate.c
index ca56f9b..208e147 100644
--- a/src/iterate.c
+++ b/src/iterate.c
@@ -320,7 +320,7 @@ chunk_render(PyObject *self, PyObject *args) {
     state.rendermode = rendermode = render_mode_create(PyString_AsString(rendermode_py), &state);
     Py_DECREF(rendermode_py);
     if (rendermode == NULL) {
-        return Py_BuildValue("i", "-1");
+        return NULL;
     }
 
     /* get the image size */
diff --git a/src/rendermode-cave.c b/src/rendermode-cave.c
index c29a8a5..e68578f 100644
--- a/src/rendermode-cave.c
+++ b/src/rendermode-cave.c
@@ -178,7 +178,6 @@ static int
 rendermode_cave_start(void *data, RenderState *state, PyObject *options) {
     RenderModeCave* self;
     int ret;
-    PyObject *opt;
     self = (RenderModeCave *)data;
 
     /* first, chain up */
@@ -186,26 +185,17 @@ rendermode_cave_start(void *data, RenderState *state, PyObject *options) {
     if (ret != 0)
         return ret;
     
-    opt = PyDict_GetItemString(options, "depth_tinting");
-    if (opt) {
-        self->depth_tinting = PyObject_IsTrue(opt);
-    } else {
-        self->depth_tinting = 1;
-    }
+    self->depth_tinting = 1;
+    if (!render_mode_parse_option(options, "depth_tinting", "i", &(self->depth_tinting)))
+        return 1;
 
-    opt = PyDict_GetItemString(options, "only_lit");
-    if (opt) {
-        self->only_lit = PyObject_IsTrue(opt);
-    } else {
-        self->only_lit = 0;
-    }
-
-    opt = PyDict_GetItemString(options, "lighting");
-    if (opt) {
-        self->lighting = PyObject_IsTrue(opt);
-    } else {
-        self->lighting = 0;
-    }
+    self->only_lit = 0;
+    if (!render_mode_parse_option(options, "only_lit", "i", &(self->only_lit)))
+        return 1;
+    
+    self->lighting = 0;
+    if (!render_mode_parse_option(options, "lighting", "i", &(self->lighting)))
+        return 1;
 
     /* if there's skylight we are in the surface! */
     self->skylight = PyObject_GetAttrString(state->self, "skylight");
diff --git a/src/rendermode-lighting.c b/src/rendermode-lighting.c
index 88c8d57..6285724 100644
--- a/src/rendermode-lighting.c
+++ b/src/rendermode-lighting.c
@@ -168,7 +168,6 @@ do_shading_with_mask(RenderModeLighting *self, RenderState *state,
 
 static int
 rendermode_lighting_start(void *data, RenderState *state, PyObject *options) {
-    PyObject *opt;
     RenderModeLighting* self;
 
     /* first, chain up */
@@ -178,16 +177,9 @@ rendermode_lighting_start(void *data, RenderState *state, PyObject *options) {
     
     self = (RenderModeLighting *)data;
 
-    opt = PyDict_GetItemString(options, "shade_strength");
-    if (opt) {
-        if (!PyNumber_Check(opt)) {
-            PyErr_SetString(PyExc_TypeError, "'shade_strength' must be a number");
-            return 1;
-        }
-        self->shade_strength = PyFloat_AsDouble(opt);
-    } else {
-        self->shade_strength = 1.0;
-    }
+    self->shade_strength = 1.0;
+    if (!render_mode_parse_option(options, "shade_strength", "f", &(self->shade_strength)))
+        return 1;
     
     self->black_color = PyObject_GetAttrString(state->chunk, "black_color");
     self->facemasks_py = PyObject_GetAttrString(state->chunk, "facemasks");
diff --git a/src/rendermode-normal.c b/src/rendermode-normal.c
index 0d41ed4..bf72fc7 100644
--- a/src/rendermode-normal.c
+++ b/src/rendermode-normal.c
@@ -19,44 +19,23 @@
 
 static int
 rendermode_normal_start(void *data, RenderState *state, PyObject *options) {
-    PyObject *opt, *chunk_x_py, *chunk_y_py, *world, *use_biomes, *worlddir;
+    PyObject *chunk_x_py, *chunk_y_py, *world, *use_biomes, *worlddir;
     RenderModeNormal *self = (RenderModeNormal *)data;
     
     /* load up the given options, first */
     
-    opt = PyDict_GetItemString(options, "edge_opacity");
-    if (opt) {
-        if (!PyNumber_Check(opt)) {
-            PyErr_SetString(PyExc_TypeError, "'edge_opacity' must be a number");
-            return 1;
-        }
-        self->edge_opacity = PyFloat_AsDouble(opt);
-    } else {
-        self->edge_opacity = 0.15;
-    }
+    self->edge_opacity = 0.15;
+    if (!render_mode_parse_option(options, "edge_opacity", "f", &(self->edge_opacity)))
+        return 1;
     
-    opt = PyDict_GetItemString(options, "min_depth");
-    if (opt) {
-        if (!PyInt_Check(opt)) {
-            PyErr_SetString(PyExc_TypeError, "'min_depth' must be an integer");
-            return 1;
-        }
-        self->min_depth = PyInt_AsLong(opt);
-    } else {
-        self->min_depth = 0;
-    }
+    self->min_depth = 0;
+    if (!render_mode_parse_option(options, "min_depth", "I", &(self->min_depth)))
+        return 1;
+
+    self->max_depth = 127;
+    if (!render_mode_parse_option(options, "max_depth", "I", &(self->max_depth)))
+        return 1;
 
-    opt = PyDict_GetItemString(options, "max_depth");
-    if (opt) {
-        if (!PyInt_Check(opt)) {
-            PyErr_SetString(PyExc_TypeError, "'max_depth' must be an integer");
-            return 1;
-        }
-        self->max_depth = PyInt_AsLong(opt);
-    } else {
-        self->max_depth = 127;
-    }
-    
     chunk_x_py = PyObject_GetAttrString(state->self, "chunkX");
     chunk_y_py = PyObject_GetAttrString(state->self, "chunkY");
     
diff --git a/src/rendermodes.c b/src/rendermodes.c
index 29c506e..717273c 100644
--- a/src/rendermodes.c
+++ b/src/rendermodes.c
@@ -17,6 +17,7 @@
 
 #include "overviewer.h"
 #include <string.h>
+#include <stdarg.h>
 
 /* list of all render modes, ending in NULL
    all of these will be available to the user, so DON'T include modes
@@ -174,6 +175,50 @@ void render_mode_draw(RenderMode *self, PyObject *img, PyObject *mask, PyObject
     self->iface->draw(self->mode, self->state, img, mask, mask_light);
 }
 
+/* options parse helper */
+int render_mode_parse_option(PyObject *dict, const char *name, const char *format, ...) {
+    va_list ap;
+    PyObject *item;
+    int ret;
+    
+    if (dict == NULL || name == NULL)
+        return 1;
+    
+    item = PyDict_GetItemString(dict, name);
+    if (item == NULL)
+        return 1;
+    
+    /* make sure the item we're parsing is a tuple
+       for VaParse to work correctly */
+    if (!PyTuple_Check(item)) {
+        item = PyTuple_Pack(1, item);
+    } else {
+        Py_INCREF(item);
+    }
+    
+    va_start(ap, format);
+    ret = PyArg_VaParse(item, format, ap);
+    va_end(ap);
+    
+    Py_DECREF(item);
+    
+    if (!ret) {
+        PyObject *errtype, *errvalue, *errtraceback;
+        const char *errstring;
+        
+        PyErr_Fetch(&errtype, &errvalue, &errtraceback);
+        errstring = PyString_AsString(errvalue);
+        
+        PyErr_Format(PyExc_TypeError, "rendermode option \"%s\" has incorrect type (%s)", name, errstring);
+        
+        Py_DECREF(errtype);
+        Py_DECREF(errvalue);
+        Py_XDECREF(errtraceback);
+    }
+    
+    return ret;
+}
+
 /* bindings for python -- get all the rendermode names */
 PyObject *get_render_modes(PyObject *self, PyObject *args) {
     PyObject *modes;
diff --git a/src/rendermodes.h b/src/rendermodes.h
index c867bf2..e27cb15 100644
--- a/src/rendermodes.h
+++ b/src/rendermodes.h
@@ -81,6 +81,10 @@ void render_mode_destroy(RenderMode *self);
 int render_mode_occluded(RenderMode *self, int x, int y, int z);
 void render_mode_draw(RenderMode *self, PyObject *img, PyObject *mask, PyObject *mask_light);
 
+/* helper function for reading in rendermode options
+   works like PyArg_ParseTuple on a dictionary item */
+int render_mode_parse_option(PyObject *dict, const char *name, const char *format, ...);
+
 /* python metadata bindings */
 PyObject *get_render_modes(PyObject *self, PyObject *args);
 PyObject *get_render_mode_info(PyObject *self, PyObject *args);