diff --git a/src/main.rs b/src/main.rs
index 7556afa..8bea18f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -171,7 +171,6 @@ fn random_world() -> HittableList {
 }
 
 fn from_obj(path: &str) -> HittableList {
-
     let mut world = HittableList::new();
 
     let material_ground = Arc::new(Lambertian::new(&Color::new(0.05, 0.05, 0.05)));
@@ -216,30 +215,31 @@ fn from_obj(path: &str) -> HittableList {
                 Point3::new(
                     mesh.positions[3 * index_a] as f64,
                     mesh.positions[3 * index_a + 1] as f64,
-                    mesh.positions[3 * index_a + 2] as f64
+                    mesh.positions[3 * index_a + 2] as f64,
                 ),
                 Point3::new(
                     mesh.positions[3 * index_b] as f64,
                     mesh.positions[3 * index_b + 1] as f64,
-                    mesh.positions[3 * index_b + 2] as f64
+                    mesh.positions[3 * index_b + 2] as f64,
                 ),
                 Point3::new(
                     mesh.positions[3 * index_c] as f64,
                     mesh.positions[3 * index_c + 1] as f64,
-                    mesh.positions[3 * index_c + 2] as f64
+                    mesh.positions[3 * index_c + 2] as f64,
                 ),
-                material.clone()
+                material.clone(),
             )));
         }
     }
     return world;
-    
 }
 
 // The output is wrapped in a Result to allow matching on errors
 // Returns an Iterator to the Reader of the lines of the file.
 fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
-where P: AsRef<Path>, {
+where
+    P: AsRef<Path>,
+{
     let file = File::open(filename)?;
     Ok(io::BufReader::new(file).lines())
 }
@@ -264,10 +264,10 @@ fn main() {
 
     // Image
     let aspect_ratio = 16.0 / 9.0;
-    let image_width = 200;
+    let image_width = 600;
     let image_height = (image_width as f64 / aspect_ratio) as u32;
-    let samples_per_pixel = 100_u32;
-    let max_depth = 5;
+    let samples_per_pixel = 50_u32;
+    let max_depth = 50;
 
     let vfov = 50.0;
     let lookfrom = Point3::new(30.0, 20.0, 30.0);
@@ -276,6 +276,12 @@ fn main() {
     let dist_to_focus = 40.0;
     let aperture = 0.1;
 
+    // limit rayon multithreading thread count
+    let thread_count = 4; // if 0, for each logical cpu core a thread wil be created
+    if thread_count > 0 {
+        env::set_var("RAYON_NUM_THREADS", "4");
+    }
+
     let world = from_obj("obj/Lowpoly_tree_sample copy.obj");
 
     // World