diff --git a/rtchallenge/examples/eoc2.rs b/rtchallenge/examples/eoc2.rs
index 8c0be9c..afcc7aa 100644
--- a/rtchallenge/examples/eoc2.rs
+++ b/rtchallenge/examples/eoc2.rs
@@ -3,6 +3,7 @@ use anyhow::{bail, Result};
 use rtchallenge::{
     canvas::Canvas,
     tuples::{Color, Tuple},
+    Float,
 };
 
 #[derive(Debug)]
@@ -47,8 +48,8 @@ fn main() -> Result<()> {
     let bg = Color::new(0.2, 0.2, 0.2);
     let mut c = Canvas::new(w, h, bg);
     let mut i = 0;
-    let w = w as f32;
-    let h = h as f32;
+    let w = w as Float;
+    let h = h as Float;
     while p.position.y > 0. {
         p = tick(&e, &p);
         println!("tick {}: proj {:?}", i, p);
diff --git a/rtchallenge/examples/eoc4.rs b/rtchallenge/examples/eoc4.rs
index 4463a62..054888f 100644
--- a/rtchallenge/examples/eoc4.rs
+++ b/rtchallenge/examples/eoc4.rs
@@ -1,11 +1,11 @@
-use std::f32::consts::PI;
-
 use anyhow::Result;
 
 use rtchallenge::{
     canvas::Canvas,
+    float::consts::PI,
     matrices::Matrix4x4,
     tuples::{Color, Tuple},
+    Float,
 };
 
 fn draw_dot(c: &mut Canvas, x: usize, y: usize) {
@@ -30,13 +30,13 @@ fn main() -> Result<()> {
     let rot_hour = Matrix4x4::rotation_z(-PI / 6.);
 
     let mut p = t * p;
-    let w = w as f32;
-    let h = h as f32;
+    let w = w as Float;
+    let h = h as Float;
     // The 'world' exists between -0.5 - 0.5 in X-Y plane.
     // To convert to screen space, we translate by 0.5, scale to canvas size,
     // and invert the Y-axis.
     let world_to_screen =
-        Matrix4x4::scaling(w as f32, -h as f32, 1.0) * Matrix4x4::translation(0.5, -0.5, 0.);
+        Matrix4x4::scaling(w as Float, -h as Float, 1.0) * Matrix4x4::translation(0.5, -0.5, 0.);
     for _ in 0..12 {
         let canvas_pixel = world_to_screen * p;
         draw_dot(&mut c, canvas_pixel.x as usize, canvas_pixel.y as usize);
diff --git a/rtchallenge/examples/eoc5.rs b/rtchallenge/examples/eoc5.rs
index e1d3251..c30baf5 100644
--- a/rtchallenge/examples/eoc5.rs
+++ b/rtchallenge/examples/eoc5.rs
@@ -6,6 +6,7 @@ use rtchallenge::{
     rays::Ray,
     spheres::{intersect, Sphere},
     tuples::{Color, Tuple},
+    Float,
 };
 
 fn main() -> Result<()> {
@@ -16,7 +17,7 @@ fn main() -> Result<()> {
     let ray_origin = Tuple::point(0., 0., -5.);
     let wall_z = 10.;
     let wall_size = 7.;
-    let pixel_size = wall_size / w as f32;
+    let pixel_size = wall_size / w as Float;
     let half = wall_size / 2.;
     let color = Color::new(1., 0., 0.);
     let mut shape = Sphere::default();
@@ -25,9 +26,9 @@ fn main() -> Result<()> {
     );
 
     for y in 0..h {
-        let world_y = half - pixel_size * y as f32;
+        let world_y = half - pixel_size * y as Float;
         for x in 0..w {
-            let world_x = -half + pixel_size * x as f32;
+            let world_x = -half + pixel_size * x as Float;
             let position = Tuple::point(world_x, world_y, wall_z);
             let r = Ray::new(ray_origin, (position - ray_origin).normalize());
             let xs = intersect(&shape, &r);
diff --git a/rtchallenge/examples/eoc6.rs b/rtchallenge/examples/eoc6.rs
index 959c22f..c597296 100644
--- a/rtchallenge/examples/eoc6.rs
+++ b/rtchallenge/examples/eoc6.rs
@@ -7,7 +7,7 @@ use rtchallenge::{
     rays::Ray,
     spheres::{intersect, Sphere},
     tuples::{Color, Tuple},
-    WHITE,
+    Float, WHITE,
 };
 
 fn main() -> Result<()> {
@@ -18,7 +18,7 @@ fn main() -> Result<()> {
     let ray_origin = Tuple::point(0., 0., -5.);
     let wall_z = 10.;
     let wall_size = 7.;
-    let pixel_size = wall_size / w as f32;
+    let pixel_size = wall_size / w as Float;
     let half = wall_size / 2.;
     let mut shape = Sphere::default();
     shape.material = Material {
@@ -33,9 +33,9 @@ fn main() -> Result<()> {
     let light = PointLight::new(light_position, light_color);
     let in_shadow = false;
     for y in 0..h {
-        let world_y = half - pixel_size * y as f32;
+        let world_y = half - pixel_size * y as Float;
         for x in 0..w {
-            let world_x = -half + pixel_size * x as f32;
+            let world_x = -half + pixel_size * x as Float;
             let position = Tuple::point(world_x, world_y, wall_z);
             let direction = (position - ray_origin).normalize();
             let r = Ray::new(ray_origin, direction);
diff --git a/rtchallenge/examples/eoc7.rs b/rtchallenge/examples/eoc7.rs
index 959b005..c0ff874 100644
--- a/rtchallenge/examples/eoc7.rs
+++ b/rtchallenge/examples/eoc7.rs
@@ -1,10 +1,11 @@
-use std::{f32::consts::PI, time::Instant};
+use std::time::Instant;
 
 use anyhow::Result;
 use structopt::StructOpt;
 
 use rtchallenge::{
     camera::{Camera, RenderStrategy},
+    float::consts::PI,
     lights::PointLight,
     materials::Material,
     matrices::Matrix4x4,
diff --git a/rtchallenge/examples/eoc8.rs b/rtchallenge/examples/eoc8.rs
index 1749eeb..a2eb07a 100644
--- a/rtchallenge/examples/eoc8.rs
+++ b/rtchallenge/examples/eoc8.rs
@@ -1,10 +1,11 @@
-use std::{f32::consts::PI, time::Instant};
+use std::time::Instant;
 
 use anyhow::Result;
 use structopt::StructOpt;
 
 use rtchallenge::{
     camera::{Camera, RenderStrategy},
+    float::consts::PI,
     lights::PointLight,
     materials::Material,
     matrices::Matrix4x4,
@@ -31,7 +32,7 @@ fn main() -> Result<()> {
     let light_position = Tuple::point(-10., 10., -10.);
     let light_color = WHITE;
     let light = PointLight::new(light_position, light_color);
-    let mut camera = Camera::new(width, height, PI / 4.);
+    let mut camera = Camera::new(width, height, PI / 2.);
     let from = Tuple::point(0., 1.5, -5.);
     let to = Tuple::point(0., 1., 0.);
     let up = Tuple::point(0., 1., 0.);