Webcam C525

This page describes how I modified a Logitech C525 webcam for use as a lunar or planetary camera. These modifications void the Logitech warrantee and may ruin the camera, so proceed at your own risk.

To make this camera, purchase a Logitech C525 webcam from BestBuy or other electronics supplier. It costs ~$50. It contains a 2 MPixel CMOS sensor, capable of 30 frames per second video at 640x480 resolution, and at least 20 to 25 frames per second at 600 x 800 resolution or higher.

Un-package the web cam, then pry off the Logitech faceplate around the lens. It is only held on with adhesive. Don’t worry about damaging the face plate; it is no longer needed.

Underneath the face place, you will see four small black screws. Remove them.

Remove the inner housing and electronics assembly from the outer black housing.

Using a jeweler’s screw driver or small needle nosed pliers, rip off the metal lens housing. Then, using some force, rip off the lens and auto focus electrical coil. After you remove the autofocus coil, carefully remove as much remaining visible auto focus wire as possible from around the sensor.

The C525, unlike some earlier models, has the infrared blocking filter in the lens assembly, not on the sensor. This is good, because it gives you the most flexibility in using colored or infrared filters. On the other hand, you must purchase an IR blocking filter, or you will get poor image quality for most solar system work. I purchased a Meade CCD red-green-blue-IR filter set for $20.

If you are careful, you might be able to remove the Logitech IR filter from the lens assembly and cement it over the CMOS sensor. I tried this, but shattered the filter.

After exposing the CMOS sensor and clearing wires, get an eyepiece barrel having threads to accept threaded filters. You might need to cut a notch to allow the barrel to sit flush around the sensor, and clear the cylindrical microphone or other components. I used a Dremel tool for this. Then, make a string cross hair that crosses near the center of the eyepiece barrel. This is needed to center the sensor.

Attach the eyepiece barrel to the inner housing of the webcam using adhesive caulk or epoxy. Use the strings to center the CMOS sensor in the barrel as best you can. The better your centering, the easier it is to find objects (such as Jupiter or Saturn) at the telescope.

Use some wire or tape to hold things together until the adhesive cures. Use some black electrical tape to cover the status LED; otherwise, it will spray light onto the sensor.

After the caulk or epoxy cures, remove all the tape or other temporary construction aids. Then, using a clean cotton applicator (such as a Q-tip) and a dilute mixture of isopropyl alcohol, gently clean the sensor surface of debris. It needs to be very clean to avoid black spots on the image.

This is the finished product. Keep it stored in an electrostatic bag to protect the exposed electronics.

To control the camera, I recommend using the freeware SharpCap (http://www.sharpcap.co.uk/), which is developed for amateur astronomical imaging using webcams. Image processing can be done in Registax (http://www.astronomie.be/registax/), which is also free.

You are now ready to image!