How to Measure Camera Lenses for Filters

Camera filters are a simple and inexpensive way to add effects to basic camera lenses. Filters come in the same sizes as lenses. If your lenses are 35 mm, then 18 to 35 mm filters will fit.The same rule applies if the lenses measured are 12 mm, then you know 11 to 18 mm lenses would fit and so on. The only tricky part is finding out the size of your lenses. Follow these helpful steps.

Difficulty: Easy

Instructions

Things You'll Need:

• Camera lenses
• Ruler
• String
• Marker

1. 
   Camera lens with size on the side

   Look at the side of the lens. On any SLR or point and shoot lens, the size should have the size written on the lens. If not, look at the front of the lens. It should read a number like 18 to 35 mm or 17 to 55mm and so on.

2. 
   Front of camera lens (this one has the size on it)

   If you can't find the number on the lens, get a piece of string and hold it across the front glass part of the lens. Mark the sides of the string.

3. Measure the marked string by millimeters. If you only have metric ruler, here's a cheat sheet: 1 inch equals 2.54 cm; 1 cm equals 10 mm and 1 inch equals (2.54 x 10) mm equals 25.4 mm. The number you get, say your lens is 35 mm across, that is the number that you will use for sizing.

Tips & Warnings

• Many manufacturers make special lenses and filters for their point and shoot cameras. Check the manufacturer's website to see if it has special filters for your camera's make and model.

Resources

• B&H Photo for camera equipment

[alex12347]

on 9/8/2009 The size of the lens filter means the diameter of the end of the lens. For a filter to fit a lens, they need to be exactly the same size!

The measurements in mm written on the lens, e.g. 18-55mm, refers to the focal length of the lens, which is something completely different!