Stick the lens through the hole. With your free hand grip the lens to focus and compose the shot.

Secure the bottom two suction cups near the middle of the device until it forms an upside-down trapezoid.

Place the top two suction cups on the window as far apart as they will go and secure them in place.

Note based on comments: This is different than using a polarizing filter or a rubber lens hood. A polarizing filter will add another piece of glass between the sensor/window, not block 100% of the reflections, as well as add a stop to the exposure. A rubber lens hood works great when shooting directly straight, but offers less flexibility when composing your shot or shooting at angles.

Flect is a simple device I developed to take photos through glass without reflections or glare from the surrounding environment. Follow the steps below to learn about the device before you take the time to make one for yourself.

DIY Tutorial

This 9-step tutorial will take about 30 minutes to complete once you have all your necessary items. It was designed to be easy to build with store-bought products and without any sewing.

Step 1 To complete this project, you'll need: black canvas, shearing scissors, 4 small suction cups, 4 medium safety pins, duct, masking, or gaffers tape, a tool of measurement, an X-Acto knife, and a flat, fairly clean, surface. Once all the materials are gathered, cut the fabric into a rectangle. Mine was cut at 16"x11". Note: I wouldn't cut much smaller than this, as you want to give yourself plenty of fabric to block the surrounding environment.

Step 2 When the fabric is finally cut, you'll want to take your X-Acto knife and poke a small hole in each corner of the fabric. The hole should be roughly 3/4 of an inch from either edge of the fabric. After the hole is created, slide the nub of the suction cup through the hole. Note: I pretty much eye-balled this at the time of creating it and only measured when I was writing the instructions. Just make sure it's not too close to the edge to avoid the potential of it getting ripped off the fabric upon removal from a window.

Step 3 A simple way of fastening the suctions cups to the fabric is with the use of a safety pin. To do this, weave the pin through the fabric, then the suction cup, then back through the fabric before closing the safety pin. Note: Make sure to grab as much of the fabric as possible. Doing so will help protect the suction cups upon removal from a window. Disclaimer: I'm not responsible for any blood, tears, or foul language that may result in this step of the process.

Step 4 When all 4 corners have suction cups pinned to the fabric, fold the fabric into 4 quadrants. In doing this, you'll be able to find the exact center of the fabric to make a small hole. This hole will allow you to stick your lens through the opening to take photographs.

Step 5 You'll want to measure the width of the lens before you begin cutting. You'll want to make sure the opening will be big enough for your use. Once you have the width, stick your scissors through the hole and cut an "X" into the fabric. Note: If you want to tape the edges of the cut, feel free to do so (I have not done this with mine). You'll learn the method for this in the next steps.

Step 6 Take a piece of tape long enough for one of the sides and lay half of it on the front and fold the other half to the back. Make sure you don't cover the suction cups. Run your finger along the tape on both sides to smooth out the surface. Use your X-Acto knife to cut the excess tape from the edges. Note: The first time I made this I used masking tape, for the tutorial I used duct tape. Feel free to use whatever tape you feel appropriate.

Step 7 Apply tape to all sides and make sure to cut off the extra tape from the edges. Depending on how wide your tape is, you'll mostly cover the safety pins. Take a little extra tape and cover the edges.

Step 8 The final product should be small enough to fit easily into your camera bag, back pocket, coat, or whatever else you carry with you when you are taking photos.