The Converging Lens Image Formation Interactive is an adjustable size file that displays nicely on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The compatibility with tablets such as iPads and with Chromebooks make it a perfect tool for use in a 1:1 classroom. This Interactive does not display well on all smart phones and The Physics Classroom does not recommend its use on all smart phones.


Teaching Ideas and Suggestions:

The Converging Lens Image Formation Interactive simulates the refraction of light from selected locations on an object through a converging lens to form an image. Students are presented with an object - the letter L - and tap on a location of the letter. Two principal rays are drawn from the tapped-on point towards and through the lens. Their intersection is shown and the image is located. The process of tapping on points continues as the simulation locates the new image for every tap. Once the student has tapped five or more times, a button appears that states Draw All Rays. Tapping on this button will scan the entire letter and draw rays for each point on the letter. The entire image is thereby constructed. 

This process can be repeated for other letters positioned at various locations along the Principal Axis - both above it and below it. Each time the complete image is constructed - by tapping on the Draw All Rays button - a menu appears on the right side of the Interactive with a set of choices as to what to do next. There are four different letters that can be investigated individually. These four letters are part of the phrase LENS IMAGE. Students can also view the image of the entire phrase. 

We suggest that this Interactive can be used at two distinct points within the learning cycle on lenses and their images. No matter where it is used, it is important that it not be used as to support and not to supplant the hands-on component of the unit. We suggest that it be used early in the learning cycle after a hands on experience with lenses that is more exploratory in nature. For instance, students could use inexpensive magnifying glasses to view the images of objects ... such as their own self or printed letters on a page. This simulation could be used as an immediate follow up of such an activity to demonstrate how an image is formed of each individual point on the object. The entire image is actually a collection of point images.

This Interactive could also be used near the end of the learning cycle of a unit on lenses. After students have learned how to draw ray diagrams and how the image characteristics are dependent upon the object location, allow students to explore a more complex object such as the letters of LENS IMAGE. We have made available an activity that would assist with the use of this Interactive in the latter stages of the learning cycle. The activity was originally developed by Chris from Nerd Island Studios (the creator of this simulation). We have made some small modifications of it to make it fit more seamlessly with the rest of our website. View Activity.




Related Resources

There are numerous resources at The Physics Classroom website that serve as very complementary supports for the Converging Lens Image Formation Interactive. These include:
  • Minds On Physics Internet Modules:
    The Minds On Physics Internet Modules include a collection of interactive questioning modules that help learners assess their understanding of physics concepts and solidify those understandings by answering questions that require higher-order thinking. Assignments RL7, RL8, and RL9 of the Refraction and Lens module provide great complements to this Interactive. They are best used in the middle to later stages of the learning cycle. Visit the Minds On Physics Internet Modules.

    Users may find that the App version of Minds On Physics works best on their devices. The App Version can be found at the Minds On Physics the App section of our website. The Reflection and Mirrors module can be found on Part 6 of the six-part App series. Visit Minds On Physics the App.

  • Curriculum/Practice: Several Concept Development worksheets at the Curriculum Corner will be very useful in assisting students in cultivating their understanding, most notably ...

    Ray Diagrams for Converging Lenses
    Ray Diagrams for Diverging Lenses
    Lenses and Mirrors - Applying Concepts
    Lens Practice

    Visit the Curriculum Corner.

  • Labwork: 
    Simulations should always support (never supplant) hands-on learning. The Laboratory section of The Physics Classroom website includes several hands-on ideas that complement this Interactive. Three notable lab ideas include ...

    Exploring Lens Lab
    The L•O•S•T Art of Image Description
    Lens Equation Lab

    Visit The Laboratory.

  • Science Reasoning Activities:
    Science classrooms should be filled with reasoning activities. There are two related activities in the Refraction section of the Science Reasoning Center and at the ACT Test Center that will challenge students to employ close reading, data analysis, and logical reasoning. The activities are named ...

    Lens Magnification Lab
    Depth of Field

    Visit the Science Reasoning Center.

    Visit ACT Test Center.

Additional resources and ideas for incorporating Converging Lens Image Formation into an instructional unit on light refraction and lenses can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.



The Physics Classroom would like to extend a special thanks to Nerd Island Studios for the creation of this HTML5 Interactive for the Physics Interactives collection. Visit to see more great stuff by Nerd Island Studios.

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