Often, the effect or benefits of using filters can’t be replicated during processing and many remain just as essential in this digital era.
While a lot is written about filter systems and slot-in type filters, traditional circular screw-in filters often get a little overlooked. This is rather odd, given the variety and unique benefits offered by certain screw-in type filters.
Screw-in filters are typically constructed from optical glass, and high-quality versions boast elaborate multi-coatings to minimize glare and maximize image quality. They are also easy to use; simply screwing directly onto to the front of the lens via the lens’s filter thread. They are available in various, specific lens diameters to fit different optics – typically ranging from 52mm to 82mm.
Used well and applied appropriately, filters have the ability to greatly enhance our photographs – in fact they can completely transform them. Our guide to screw-in filters for landscape photography will help arm you with the knowledge and knowhow to buy just the filters you need.
Lets begin by looking at a few filter types that you don’t really need in the digital era. Cooling-down and warming-up filters once played an integral role in film photography, with their role being to neutralize colour casts, created by different light types. However, your digital camera’s white balance setting is designed to do this job – colour temperature can now be controlled easily in-camera with just the push of a button. And, if you shoot in Raw, you can also adjust and fine-tune colour temperature just as easily during processing.
Soft focus filters also used to be popular – although not necessarily with landscape photographers. Again, the effect is easily replicated in Photoshop using tools like Gaussian Blur. You can also achieve a similar effect by taking a double exposure – a function available on an increasing number of digital SLRs. This is simple enough to do by taking one frame sharply focused and then shooting the next frame de-focused. Again, if this is an effect you wish to apply to your landscape photographs, you will find you have far more control doing it using software. I would strongly recommend you save your money and put it towards other more essential filter types instead.
Stepping rings are designed to adapt a filter to a lens when they have different diameters. For example, lets say you have a filter with a 77mm thread size, but wish to attach it to a lens with a diameter of 67mm. A suitable step-down ring would allow you to do this. They are made from either plastic or metal, are relatively cheap and can be purchased in a range of sizes, to suit a different combination of threads. Step-down rings allow larger filters to be used on smaller thread fit lenses and are a good method of increasingly the compatibility and usefulness of your quality screw-in filters. Step-up rings are used for attaching smaller filters to larger diameter lenses, but are generally less practical, as they increase the likelihood of vignetting.
In my opinion, there are a handful of filters types that remain essential today – including UV, Protector, Polarizing and solid Neutral Density (ND).
UV filters appear completely clear, but they are designed to absorb the effects of ultraviolet light, which can reduce contrast. Digital sensors are capable of recording UV light that is invisible to our sensory system, but a UV filter will block UV wavelengths. They are particular useful when shooting landscape photographs at higher altitudes, filtering out the greater concentration of UV light found at height, which would otherwise add a cool blue hue to images. They are also useful when photographing wintry weather, when the atmosphere is naturally cooler. Snow is known for reflecting UV light; so attaching a UV filter will help neutralize the effect.
Skylight filters are also available and are very similar in principal. However, they are tinted with a weak pink colouring to add subtle warmth to shadows. As UV filters are clear and do not absorb any light, they can also be used as a protector, to guard the lens from any damage.
This particular image required no creative filtration whatsoever. I wanted to silhouette the castle against the colourful rising sun. I needed a relatively fast shutter to capture the gulls in flight so I didn’t wish to use a solid ND filter and a polariser would have had little effect. The only filter I used was a UV on the front of my 70-200mm tele-zoom in order to keep the front element protected from sea spray, sand and damage.
Optics are valuable and delicate, so it is makes sense to always do your best to protect the front element of the lens from getting scratched or damaged. While UV or Skylight filters can be employed to do the job, you can buy dedicated protect filters. They are completely clear and designed to be kept permanently attached to the lens – although you might want to remove them when using other filter types or a holder.
Protect filters do exactly that, guarding the front element of the lens against dust, dirt, sand, moisture and scratches. Manfrotto Professional Protect filters are designed with the professional and enthusiast in mind, who require maximum protection. The filter is water repellent and constructed to repel scratches and oil while boasting an antistatic and anti-reflective coating. Overall, a protect filter is a very wise investment, potentially saving you huge sums should you drop your lens – after all, it is much cheaper to replace a damaged filter than it is a lens.
When shooting landscape photographs in challenging weather conditions – when spray, snow, dust or sand are being blown toward the camera – I would recommend you keep a UV or Protect filter attached to your lens to ensure it stays clean and damage free.
For landscape photography, a polarizer is a must have filter. Arguably, no other in-camera filter will have a greater impact on your images. Polarized light causes glare and reflections, reducing the intensity of a surface’s colour. By blocking polarized light from entering the lens, a polarizing filter is able to restore natural saturation, contrast and vibrancy. Doing so will result in photographs with added punch and oomph.
Polarizers are typically circular, screw-in type filters. They are made from a thin foil of polarizing material sandwiched between two circular pieces of glass. By rotating the filter in its mount, you can alter the amount of polarized light passing through, allowing you to precisely control the filter’s effect. They are intuitive to use. Simply peer through the camera’s viewfinder (or use LiveView) while simultaneously rotating the filter. You should be able to see reflections come and go and the intensity of colours strengthen and fade. It is worth noting that the strength of a polarizer’s effect depends on the angle of the camera in relation to the sun. The sun contains most polarized light in the areas that are at 90degrees to it. Therefore, taking photographs at a 90degree angle to the sun will create the most pronounced effect – known as ‘Brewster’s angle’. Metallic objects, like polished steel and chrome plate, do not reflect polarised light and so remain unaffected by the filter.
Using the filter is very easy; simply rotate it until you achieve the effect you like. For landscape photography, a polarizer is most popular for making blue skies appear more vibrant. However, it is also useful for reducing the glare reflecting from wet and shiny leaves and foliage, making it a very useful filter for photography of woodland interiors, rural views and even close-ups of flowers.
Manfrotto (famous for its quick release filter adapters) is among the brands producing high quality polarizing filters, available in a variety of lens diameters up to 82mm in size. Arguably, a polarizer is the most useful and essential landscape filter. Manfrotto’s Pro version includes 12 layers of coating for maximum image quality, allowing an impressive 90% light transmission. It is a filter with the potential to transform your images.
Although they are best known for their effect on clear blue skies, polarizers are great filters when shooting water and woodland interiors. They will eliminate the glare from water and radiating from wet, shiny leaves in order to produce results with far more colour saturation and impact.
Polarizing filters are renowned for their effect on blue skies. When I shot these colourful beach huts, I adopted a low angle and rotated my polarizer until the sky looked at its most saturated in order to achieve maximum impact.
The full effect of a polarizing filter can look very seductive through the viewfinder. However, the most pronounced effect will not always produce the best, or most natural looking result. Be mindful of this when using one. When fully polarized, you can encounter certain problems, for example over polarization. This will create unnatural looking results, so be careful not to overdo the effect. Cloudless skies and photographs taken at higher altitudes are at most risk of looking too dark. You should be able to detect the problem through the viewfinder, but always review your images and check that skies remain natural looking. If skies look too dark, simply reduce the level of polarization by rotating the filter.
Uneven polarization is another common problem. At certain angles to the sun, you may find the effect of the filter is irregular – with the sky being darker in some areas, more than others. Short focal lengths, between 16-35mm, are most prone to the problem due to the broad expanse of sky they are able to capture. To alleviate unevenly polarized skies, try reducing the level of polarization; employ a longer focal length; or (if possible) adjust your viewpoint.
Polarizing filters are available as both linear and circular types. Although both varieties are normally circular screw-in filters, the design of linear filters affects the metering accuracy of digital cameras. This is because autofocus systems polarize a percentage of light in-camera, and if the light has already been polarized by a filter, metering is effected. Circular polarizers are constructed with a wave-retardation plate, one-quarter of a wavelength think. This allows the light passing through the filter to rotate and appear un-polarized to the camera’s metering system, ensuring a correct meter reading. Therefore, always opt for the circular type design when buying a polarizer.
Polarizing filters absorb a degree a light – this is known as having a filter factor. Polarizers have a filter factor of 4x – so they absorb up to 2-stops of light. Your camera’s TTL metering will automatically adjust for this, but just be aware that shutter speed will be lengthened. For this reason, polarizers can be useful as a makeshift Neutral Density filter, in order to artificially lengthen shutter speeds to creatively blur subject motion, like moving water.
Neutral density (ND) filters are another essential, ‘must have’, landscape filter. They are simple, grey filters – available as both slot- and screw-in types – designed to absorb light. By doing so, they allow photographers to select artificially long shutter speeds in order to creatively blur subject movement. Water is the most popular element to blur, but foliage, clouds, people and animals are other subjects you may wish to apply the effect to. The impression of subject motion can really add interest, life and energy to photographs. They are available in a variety of strengths. ND filters with a density of 3-, 6- and 10-stops are the most popular. They are filters with huge creative potential.
You may wish to combine filters in order to achieve the result you require. It’s not uncommon to use a polarizing filter to restore natural colour saturation in combination with a solid ND to achieve a creative level of subject motion. In this instance, I used 6-stop solid ND filter to create this moody looking seascape.
For more information on ND filters, ND grads and extreme ND filters, please read my previous article – Using Neutral Density (ND) filters.