When is a polarising filter useful when taking pictures?
Polarising filters are true multi-talents because they combine several functions in one filter. If you get your hands on such a filter for the first time, you will immediately notice that you can adjust something. Circular polarisation filters in particular can be adjusted as desired by twisting them. Depending on the setting, the polarisation filter changes its polarisation direction and thus has two different effects:
- Displaying more intense colours - If the filter is rotated, the contrast also changes. This effect can already be seen in the viewfinder and can thus be adjusted as desired. For this reason, it is particularly worthwhile to use a polarising filter when taking landscape photographs, for example of flower meadows, in order to achieve a higher contrast. Alternatively, the colours in the picture can be altered afterwards with an image editing programme, but the less work you have to do with the photos afterwards, the better.
- Increasing or decreasing reflections - In comparison to contrast, reflections in glass panes or in water cannot be changed afterwards, but they can be changed directly when taking the picture using a polarising filter. When taking a picture with the help of a polarising filter, first focus on the desired subject. Then, by turning the filter, you can make the reflections disappear or intensify them. The use of a polarising filter is particularly worthwhile when, for example, fish are to be photographed or the photographer wants to achieve a clean reflection on a lake.
What do I use a grey filter for in photography?
ND filters, or neutral density filters or grey filters, are often used by professional photographers to guarantee an even illumination of the image. The lenses we offer are filters made of optical glass that are coloured in a light shade of grey and can be screwed, magnetically attached or plugged in front of the lens.
With a grey filter you can take very good photos, almost completely independent of the sunlight. We offer a range of different models that differ in light transmission, as shown in the table below. Furthermore, these filters are used to achieve the reproduction of surreal image effects due to the increased exposure time. This can be used to "fix" movements or so-called smearing and flowing movements, such as with flowing water and clouds.
Table for our ND filters, to calculate the correct exposure time
Below we show you a table which is useful for the use of our grey filters. It shows which neutral density filter causes which lengthening factor of the exposure. It also shows the reduction of light incidence in f-stops, as well as the value of the neutral density.
Lengthening factor Shutter speed
What is the function of an ND filter?
In principle, a grey filter is comparable to a pair of sunglasses for your camera and reduces the incidence of light on the camera sensor. This allows the exposure time of the camera to be extended by a certain factor. Grey filters are available in different strengths, which allows you to realise different exposure times and long exposures for photos. Although most of these filters appear grey or almost black, colours as well as the sharpness of the pictures are not affected. This is achieved by using high quality optical glass, which is also highly resistant to breakage. Just like the polarising filter, the effect of an ND filter on a photograph cannot be reproduced digitally.
What are graduated grey filters?
Basically, GND filters are glass filters that are darkened at one end and transparent at the other. In the middle of the filter, these two surfaces flow into each other, from clear to dark. This transition varies depending on the type of GND filter. Generally, the filters are used to balance the exposure of a scene, which in most cases consists of a light section and a darker section. This is especially the case in landscape photography, where the actual, darker subject is, for example, a forest in the foreground and in the background is the much lighter sky. The human eye is able to visualise a very large range of light and dark. This is also called the "dynamic range" of a scene.
Unfortunately, modern camera sensors are still not able to capture this dynamic range as the human eye can. Therefore, the use of graduated grey filters helps to capture the dynamic range of such a scene, for example in landscape photography, with a single exposure instead of combining several different shots with different exposure times.
How do the different types of GND filters differ and should you use them?
Soft GND filters
These types of filters have a transition that is very soft from dark to translucent. Therefore, they are suitable for scenes that have an interrupted or wide transition from light to the actual darker foreground. An example of such a shot that should be taken with a soft grey gradient filter is a mountain landscape that crosses the horizon line. But rock formations in the sea are also well suited to be photographed with the help of such a filter.
Hard GND filter
These types of filters have a hard transition from light to dark. Therefore, they are suitable for scenes that show a clear transition from the lighter sky to the darker foreground. The most useful use of dise filters is in landscape photography where no elements protrude above the horizon, for example, when phoatographing the sea with an expansive view of the ocean. In addition, this type of filter can be used when a hard transition is advantageous when shooting against the sun.
Reverse GND filter
Reverse GND filters with a "reverse transition" are very similar to the hard GND filter except for the fact that the most darkened area of the filter is right in the middle. These filters are used when photographing against a light source and where the light intensity is greatest at the horizon in the centre of the image.
Medium GND filters
Medium GND filters are very similar to those with a soft transition, but the gradient is a little harder. This makes these filters the most versatile and they can be used in almost all situations to take pictures with the sun behind you or against the sun.