Nd filter why use

There are also downsides to the screw-in filter system, the major one being the difficulties of using multiple filters at once, known a stacking filters. This is due to the outer edges of the filters being visible in the photo as you essentially extend the lens with a centimeter or two. Alternatively, you can purchase adapters but make sure that the filter is big enough to fit the lens with the widest diameter.

The square filter system is slightly more advanced than the screw-in and requires a few extra pieces of equipment in order to be properly mounted to the camera. Unlike the previous system where the filter is screwed directly onto the lens, an adapter is the first piece mounted with this square version.

The main advantage of using a square filter system is that it holds several slots where filters can be placed. This is especially important when using Graduated Neutral Density Filters. Keep in mind that there are big differences between brands both when it comes to the quality of filters and holders, and their design.

For example, in the NiSi V6 Pro system , you can place a Circular Polarizer inside the filter holder but for other brands, you might need an additional adapter. Most filter kits include adapters of different sizes but this might vary between brands. This highly depends on your preferences and budget. There are three main elements you should take into consideration when looking for the best Neutral Density Filter System: area of use, price and quality.

The area of use is perhaps the most critical question when choosing between a screw-in or square filter system. Adding the filter holder, adapter, pouches and filters seems a little overkill if you only use one Neutral Density Filter at the time. However, if you do intend to use a Graduated Filter or perhaps a Polarizer and Neutral Density Filter at the same time, the square filter system is ideal. This means the initial investment is considerably larger than if you were to purchase one or two screw-in filters.

That being said, filters from most manufacturers fit into the different filter holders so it is possible to choose a budget filter holder and higher quality filter though I do recommend sticking to the same brand for both the holder and filters. I find that a cheap alternative from any local electronic shop is the perfect place to begin.

My first Neutral Density filter was a cheap screw-on filter found at a local electronic shop. As a beginner photographer these where the perfect filters to begin with; they allowed me to use a slightly longer shutter speed but perhaps more importantly they helped me understand the relation between the essential camera settings.

I used these filters for a while before understanding that I needed a darker filter that could make it possible to achieve an even slower shutter speed.

These were a lot more expensive but the quality was also better. Having a darker filter and reaching shutter speeds of up to a few minutes made it worth it.

It took me about one year until I switched to a square filter system as I wanted to use Graduated Neutral Density Filters too. As mentioned previously, the cheapest Neutral Density Filters only add a slight darkening, not nearly enough to properly smooth out the water. For this you need a darker filter and these tend to have a less welcoming price-tag.

Understanding the difference between the darkening of filters can get a little complicated. These are the most common terms to use when talking about the degrees of darkening. Simply put, the terms tell you how much less light reaches the sensor when placing the filter in front of the lens and, consequently, how many stops you need to extend the shutter speed with.

For example, a 1 Stop ND Filter reduces the amount of light with 1 Stop and requires you to extend the shutter speed with the same. Especially when shooting in harsh light, and when the sun is intense, an ND filter can reduce the lighting right back while capturing a really cinematic feel.

Here you can read more about how it was filmed. Portraits can be beautifully enhanced by ND filters for the same reasons they make landscapes so interesting. You can play around with depth of field in bright conditions, use motion blur to powerful effect and bring your subject to the foreground with exceptional clarity. ND filters come in a lot of different shapes and sizes.

Just like a camera, the best way to figure out which one you prefer is to experiment. There are a few different types available on the market:. Fixed ND filters block a fixed f-stop of light from entering your camera. The lower the ND number, the less light it blocks from entering your camera. For example, an ND4 filter blocks out 4 f-stop of light, and an ND blocks 10 f-stops of light. Fixed ND filters are usually preferable for photographers who tend to stick to the same level of light exposure or shoot in conditions where you can take your time to set up a shot or change filters if you need to.

Use the chart below to understand the light reduction and transmission that results from each type of ND filter. As the name suggests, variable ND filters can be rotated to cover a number of f-stops. Variable ND filters are great for photographers who work with changing light conditions, when you need to shoot fast. More on variable ND filters here.

You might also come across graduated ND filters. These differ in that they reduce light across only half your image. You might choose to use this filter if you want to darken the background of a scene, usually the sky, but leave the foreground untouched. Depending on the fade effect you want to achieve, you can also find soft-edge and hard-edge graduated ND filters.

The soft-edge type produces a smooth fade and is perfect for use with uneven horizons or when objects, such as mountains, cover part of the sky.

Essentially, these filters cut polarised light from a scene to reduce glare and enhance both contrast and colours. Multifunctional ND CPL filters are useful for when you want to control both glare and light, without having to stack multiple filters to achieve the desired effect. An f-stop specifies the aperture of a lens. The smaller the f-stop number, the wider the aperture, and the shallower the depth of field.

This is where ND filters come in to block a certain number of f-stops of light, so you can use those smaller f-stops and wider apertures in any setting. The most common f-stop densities for ND filters are those with two, three or four stops.

If you want to block out even more light to capture extra long exposures or balance light in harshly lit scenes, choose a stronger ND filter with a higher number, like an ND You can also combine ND filters to achieve a larger f-stop and boost the density strength, but be careful not to end up with an undesirable vignetting effect.

The advantage of a neutral density filter is that it reduces the amount of light getting through to the sensor of your camera.

It has a variable opacity depending on the filter. To put it simply, the ND filter may be more or less black depending on your choice, which determines how useful it is. The more opaque black your ND filter is, the more light it will absorb. So why would anyone want to absorb light, you might be wondering? In two other articles I discuss how to choose an ND filter according to which criteria and also how to use an ND filter for long exposures, for example.

Here I will explain in more detail what an ND filter is used for in photography. We therefore compensate for this loss of light by adjusting one or more of the exposure settings used for taking the photo, namely:.

As I just explained, one of the main reasons for using an ND filter is to be able to slow down the shutter speed used when taking your photo. So, in which situations would this be useful? One of the great advantages of the ND filter is that it can help you achieve long exposures, especially in the middle of the day when the sun is the brightest and harshest.

Indeed, in broad daylight, it is impossible to achieve a long exposure even using optimal settings on your camera ISO at the lowest and closing the diaphragm at the maximum. The shutter speed will always be too fast and therefore the scene will not be in motion. In addition, an ND filter, as explained above, allows you to absorb light and thus increase the exposure time. Long exposure times are particularly used to achieve superb effects on large expanses of water sea, rivers, streams, fountains , but also on clouds, stars or even lines of traffic.

Your choice of ND filter will very much depend on your shooting habits shooting during the day, the evening, at night and according to the effects you want to achieve fog effect on the sea, complete smoothing of the image, etc. However, in order to use this technique you will need a tripod to hold your camera as exposure times can range from 10 seconds to several minutes!

If you want to know what an ND filter is used for, besides long exposures, this is another positive reason. These filters are particularly useful for maintaining a shallow depth of field, especially but not only! If you want to take a picture of an object or a person in the middle of the day in full sun using a very shallow depth of field e. Despite your best efforts, your photo will still be overexposed.

This is where the ND filter comes into its own. By absorbing light, it allows you to decrease the shutter speed of your camera without having to change your depth of field.

This allows you to blur your background while maintaining the correct exposure of the scene!