How to Install a Lens Filter on Canon objective

1 - First, make sure that you have the correct size filter for your lens. Look at the front of your lens and find the diameter measurement (usually marked by a symbol that looks like a circle with a line through it followed by a number, such as ø58mm).
2- Remove the lens cap from your lens and set it aside.
3- Take the filter out of its packaging and hold it by the edges, making sure not to touch the glass surface.
4 - Align the filter with the front of your lens, making sure that the threads on the filter are lined up with the threads on the lens.
5- Gently screw the filter onto the lens by turning it clockwise. Be careful not to cross-thread the filter or apply too much pressure.
6- Once the filter is snugly attached to the lens, you can adjust it as needed. If it's a polarizing filter, for example, you may want to rotate it to get the desired effect.
When you're finished using the filter, you can remove it by turning it counterclockwise and unscrewing it from the lens.