Do you still need filters for filming and photography with modern digital cameras?
The sobering answer is

"it depends"

It depends on which filter you want to use for which effect. I've summarized the available filters and how they can improve your shots here.

 

UV Filters

A UV filter is supposedly no longer needed with modern cameras, as the highly sensitive sensor already has a built-in UV and IR protection filter. The built-in filter is normally a dichroic filter, which only transmits visible light (approx. 400–700 nm). If you use a modern sensor with a very inexpensive lens that lacks good coating, you will still notice a difference, because good coating (high-quality filter) reduces reflections and stray light, which can occur especially in strong UV radiation, such as at the seaside, in the mountains, in snow, or on a very clear summer day. A UV filter in front of the lens can further improve contrast and clarity.

With expensive, high-quality lenses, this is rarely observed, as these usually have very high-quality coatings, meaning they have very high-quality anti-reflective coatings and may also have a UV filter directly on the lens.

If you were to use an inferior filter here, you might get stray light and poor or even non-existent reflections.

, since this filter is already integrated into the sensor. Does it still sometimes make sense to use one? Yes, because it provides additional protection for my lens, and the filter is much easier to clean. I can unscrew the dirty filter, and underneath is a clean lens that I can continue shooting with. Since the filter isn't curved and can be unscrewed, it's much easier to clean than the lens itself, and if it gets scratched, the UV filter can be easily and cheaply replaced. Would I use such a filter in a clean and protected environment, such as for indoor photography or night shots? No, because then I would only unnecessarily risk unwanted reflections (lens flares). Polarizing Filter (CPL) This filter is the go-to filter for all landscape photographers and users of wide-angle lenses because it only allows light to pass through from a specific direction and orientation. This makes it easy to prevent reflections and glare, provided you're positioned correctly and the filter is at the right angle. was.

I only recommend this filter if you already have some experience and can focus on details in the images, because since it blocks all reflections from certain directions, the sky can become unnaturally dark. This effect can affect the entire sky or only parts of it, depending on how the filter is set.

Glittering reflections on reflective surfaces can be significantly minimized and usually completely eliminated. This may or may not be desirable, for example, when photographing the sea. When photographing products or through glass surfaces like windows or display cases, I can avoid unwanted reflections this way.

 

Cross Polarization

Anyone who wants to photograph something highly reflective in a studio without reflections from the light source, for example, for product photography or to create 3D scans using photogrammetry, can place a cross-polarized filter in front of the camera and lens. This emits already polarized light, which changes the direction of polarization on metallic and very shiny surfaces and is completely filtered out by the filter.

Neutral Density Filter (ND)

This filter reduces the amount of light reaching the sensor, allowing you to create beautiful motion blur effects if you set the camera accordingly. Therefore, I only recommend this filter for advanced photographers who know how to properly adjust the exposure time and aperture in conjunction with the ISO. With mirrorless cameras, you can close the aperture to f/22, which means very little light reaches the sensor. This allows you to achieve a longer exposure time in combination with the lowest ISO setting. If you want background blur, this isn't possible with an aperture of f/22, as this results in maximum depth of field, the opposite effect. If the only goal is a longer exposure time, this is definitely a solution to avoid carrying too much equipment. The filter is used differently for video than for photography: Photography Here, it allows you to adjust the exposure time while maintaining the same The ISO setting can be significantly extended, allowing for so-called long exposures even during the day. Long exposures create beautiful motion blur effects on moving objects like water, cars, and similar subjects. Using a strong ND filter makes it possible to photograph places and buildings where people are always moving around without people in them. This is because all moving objects will be underexposed to appear in the photo, meaning everything that is stationary, i.e., not moving, will be sharply defined, ideally without people or their shadows. If shadows do occur, a stronger ND filter can be used to lengthen the exposure time. Video Since a video consists of many individual frames played back quickly, it is important that the transition from one frame to the next is seamless. This is achieved through motion blur, just as our eyes perceive it.
If you were to use too long an exposure time, a waterfall, for example, would look choppy and not flow smoothly.

To achieve a smooth blur transition in your images, the rule of thumb is to set the exposure time twice as fast as the frame rate. For example, at 25 frames per second, the exposure time should be set to 50. In this case, an ND 8 filter is usually used.

 

Photo & Video

Those who like to shoot with a wide aperture to achieve a beautiful background blur (bokeh effect) must use an ND filter in bright conditions.

Color Filters

Color filters can theoretically be added entirely in post-processing, but the question remains how useful an additional editing step is. Of course, LUTs (Look Up Tables) can be used, but it's easiest to work directly from the camera, especially if you want to continue working quickly and ensure you achieve the desired effect. Graduated Filters There are also filters that have gradients, such as ND filters, which become progressively lighter from top to bottom to help mask overexposed skies, or CPL filters, which only filter the lower half of the lens to reduce reflections without altering the sky. Astro Filters In cities, light pollution is significantly higher than in rural areas. Since yellow neon lights are still very common in cities, these filters are designed to filter out precisely this wavelength of visible light. Since more and more LEDs with significantly less yellow light are being used nowadays, the efficiency of these filters is decreasing. However, in some cities, more and more modern lamps are being installed that significantly reduce light pollution by directing the light cones downwards and not being brighter than necessary. I have already taken photos with and without filters, but at first glance, I couldn't see any significant difference. I will continue testing and update the article with any new findings. Mist / Diffusion Filters So-called black or white mist filters are filters that have small diffuse particles on the glass. Therefore, they are look filters that alter the image's appearance and not technical correction filters that improve the image. The filter is primarily used in the film industry to create a glow around light sources, soften skin tones, or, with a very strong effect, make scenes appear dreamlike. A diffusion filter is a creative filter that slightly reduces sharpness and contrast, diffuses light, and makes the image appear more cinematic. The difference to the "Mist" filter: Mist is just a specific type of diffusion, with a more controlled glow in the highlights. Variants Black Mist → preserves black levels, subtly reduces contrast, softens highlights. White Mist → stronger glow, overall milkier/softer. The filter strength is specified in 1/8, 1/4, 1/2, and 1 increments. The higher the value, the more intense the effect.

Uses

• In videos
  • "Cinematic" look through a softer image
  • In night shots, to make light sources appear "cinematic."
  • A subtle blur for dreamlike scenes
• In portraits, to make skin appear softer and more flawless.

Create the effect yourself?

Yes, you can easily create this effect yourself with an ideally old or very cheap UV filter

Using a coating

Simply apply a transparent grease cream (e.g., Vaseline), hairspray, gel pen, or glue stick to the filter, and you're done. The more you apply, the stronger the effect.

NAnd you can also play with it, like an uneven distribution, to achieve a very special look.

Using foil or fabric

Simply wedge a piece of fabric (e.g., pantyhose) or foil (e.g., cling film) onto the lens hood, or between the filter and the lens. Different fabrics produce different diffusion.

Using sandblasting / etching

Basically, it's possible to roughen the surface of an old filter using acid or sandblasting, similar to a matte screen, to create a diffused effect.

Tips

The coarser the structure, the stronger the glow. It's best to test with light sources in the image (e.g., a lamp or candle), as the effect will be immediately visible.

Use a cheap screw-in filter as a "sacrificial glass" to avoid damaging your lens.

Expensive filters or is the cheapest one sufficient?

Finally, the question arises: how much do you have to spend to get a good filter?

You will certainly achieve better results with more expensive filters, but there's no guarantee that a more expensive filter is always better. Since filters have different coatings that can improve image quality, such as an anti-reflective coating, but also reduce scratches or the accumulation of dirt and dust, you need to compare carefully and ideally read reviews to choose the best product for your needs.