I receive a lot of questions about usage of optical filters on DSLRs. Many people switch to DSLR from their compact digital camera these days, and generally they don't have much idea about what they are for. So I decided to write a list of the most essential filters that a DSLR owner should have so that they can take the full potential of their camera and also increase their level creativity and flexibility.

These are UV Filters, Polarizing Filters and Neutral Density or ND Filters.

1- UV Filters

This is one of the most recommended filters of all because the main puspose of using this filter on your DSLR is to protect the front-element of your lens against scratches, dust, dirt, water and so on (Read more about protecting your lens and keeping it clean). In film days,it was designed to block the UV light falling on film, digital image sensors are not that much affected by the Ultraviolet light.

Canon Lens Abbreviations and Acronyms

Lens manufacturers use abbreviations to specify the features of their lenses, and as the number of abbreviations increase with the newly added features, things become quite confusing especially for photographers who are not familiar with the lens technology.

In order to make things a bit more clear, we will present the lens types and abbreviations with descriptions in alphabetical order for the most popular lens manufacturers, starting with Canon.

AFD – Arc-Form Drive: An older type of in-lens AF motor like USM but slower and noisier.

AL - Aspheric Lens: A special design lens used to minimize aberrations. Aspheric lenses can be designed more compact and lightweight then conventional lenses.

CA – Circular Aperture: Canon lenses with multiple aperture blades shaped to give as circular an iris shape as possible, effects the bokeh.