Filters sit in front of the lens and change the light before it reaches the sensor. Some effects can be copied in editing, others cannot. This chart compares the most common types so you can see which ones solve real problems.
Chart of Common Filters
| Filter | What it does | Typical use | Watch out for |
|---|---|---|---|
| Clear or protective | Adds a layer of glass over the front element | Guarding against dust and splashes | Can add reflections or flare |
| UV | Blocks ultraviolet light | Mostly a front guard on modern cameras | Little visible effect digitally |
| Circular polarizer | Cuts glare and reflections, deepens blue skies | Landscapes, water, foliage | Loses light, uneven skies with wide lenses |
| Neutral density (ND) | Reduces light evenly | Long exposures, wide apertures in bright light | Strong versions may tint color |
| Graduated ND | Darkens one part of the frame | Bright sky above a darker land | Needs careful alignment |
| Diffusion or soft effect | Softens contrast and highlights | Portraits and dreamy looks | Reduces crispness |
Which Effects Editing Cannot Replace
- Polarizing: reflections off water and glass are hard to remove afterward.
- Neutral density: blurring moving water or clouds in daylight needs a longer exposure than the scene allows without it.
Bright-sky balance and color shifts, on the other hand, can often be handled with careful exposure bracketing and editing.
Using Filters Well
- Match the filter thread size to the lens, or use step-up rings.
- Clean glass before mounting so dust does not show.
- Rotate a polarizer slowly while watching the screen to find the strongest effect.
- Use a tripod with strong neutral density, as exposures become long.
- Remove the filter if you notice flare around bright lights.
Never look at the sun through a camera, lens or filter. A dark filter does not make direct sunlight safe for your eyes.
Size and fit are practical points. Filters screw onto the front thread of the lens, and the thread diameter, printed on the lens barrel, differs from lens to lens. Square or rectangular systems use a holder and let one set of filters serve many lenses, though they are bulkier to carry.
Glass quality varies. Poor coatings can add flare, soften detail or tint colors, so inspect the results at the edges of the frame and against bright lights. Keep filters in padded pouches and clean them with the same gentle method you use for lens glass.
FAQ
Which filter should I buy first?
A circular polarizer or a neutral density filter, depending on whether you shoot scenery with reflections or want motion blur in daylight.
Do I need a filter on every lens?
No. Using a lens hood and careful handling protects glass well in most conditions.
The Short Version
Polarizers and neutral density filters give effects that are difficult to copy later, while clear and UV types mainly protect. Choose only what solves a problem you meet often.