diff --git a/topics/02_passive/index.md b/topics/02_passive/index.md
index 353e7de9bfaf69a7cb00f7ae5ac8737088132c2c..91bb1dfa3eb4377c136193300a56add4c414daa7 100644
--- a/topics/02_passive/index.md
+++ b/topics/02_passive/index.md
@@ -59,24 +59,37 @@ Depending on the end use application almost any camera will work given there is
 <p><img src="images/lidar_vs_photogrammetry_drone.jpg" alt="Drone imaging"></p>
 
 # Key Challenges
-Precision is improving but can still be completely thrown off by certain light conditions in much the same way LiDar struggles with smooth surfaces.
+### Lighting
+Light conditions in the scene are crucial to the quality of the scan. A controlled environment is highly preferred. Precision is improving but can still be completely thrown off by certain light conditions in much the same way LiDar struggles with smooth surfaces.
 
-Increasingly industry pairs vision systems for photogrammetry with laser systems to balance the benefits of both.
-# Tools
-<p><a href="https://www.autodesk.com/products/recap/overview?term=1-YEAR">Autodesk ReCap</a></p>
-<p><a href="https://www.agisoft.com">Agisoft Metashape</a></p>
+### Precision Limitations
+ Increasingly industry pairs vision systems for photogrammetry with laser systems to balance the benefits of both.
 
 
-# Apps
-<p>iPhone and Android apps for photogrammetry and now LiDAR scanning have multiplied over the last 2 years. The primary driver is product placement, however some open source options are making way for both art and art preservation</p>
-<a href="https://www.myminifactory.com/scantheworld/">Scan the World</a>
-<p><a href="https://projectmosul.org/">Rekrei</a></p>
-<p><a href="https://www.adobe.com/products/aero.html">Adobe Aero</a></p>
-<p><a href="https://www.scandy.co/apps/scandy-pro">ScandyPro</a></p>
-<p><a href="https://www.bellus3d.com/faceapp/">Bellus</a></p>
+# Software
 
-<p><img src="images/bellus.jpg" alt="Bellus"></p>
+### Open Source
+[AliceVision](https://alicevision.org/)
 
+### Industry Standard
+[Autodesk ReCap](https://www.autodesk.com/products/recap/overview?term=1-YEAR)
+[Agisoft Metashape](https://www.agisoft.com)
+
+### ML - Powered
+<a href="https://www.pix4d.com/blog/machine-learning-meets-photogrammetry">Pix4D</a>
+<p>Improving accuracy while scraping information on the contents of photogrammetry data sets.</p>
+
+
+### Apps
+iPhone and Android apps for photogrammetry and now LiDAR scanning have multiplied over the last several years:
+
+[Scan the World](https://www.myminifactory.com/scantheworld/)
+[Rekrei](https://projectmosul.org/)
+[Adobe Aero](https://www.adobe.com/products/aero.html)
+[ScandyPro](https://www.scandy.co/apps/scandy-pro)
+[Bellus](https://www.bellus3d.com/faceapp/)
+
+<img src="images/bellus.jpg" alt="Bellus">
 
 
 
@@ -88,8 +101,7 @@ Increasingly industry pairs vision systems for photogrammetry with laser systems
 <a href="https://www.sciencedirect.com/science/article/abs/pii/0031866373900069">Welch 1973</a>
 
 # ML for Photogrammetry
-<a href="https://www.pix4d.com/blog/machine-learning-meets-photogrammetry">Pix4D</a>
-<p>Improving accuracy while scraping information on the contents of photogrammetry data sets.</p>
+
 
 # Open Source Photogrammetry