Matt Shepherd

filters explained

Posted by aquaseen on 25 June 2012 | 0 Comments

Do your images look blown out in the sky or lacking detail in the foreground? If they do then hopefully this blog will help you to achieve the shot you are looking for.

It seems to me that the most often asked question that I come across in landscape photography is about filters, so I thought it was about time I put pen to paper, or in this case fingers to keyboard, to try and help out people who are thinking about using filters for the first time.

 I'll be focusing on the filters I use since I have become very familiar with them from frequent use.

Ok, so you may have thought about filters in the past but then when you looked at purchasing them it was just all too complex and frustrating as there are so many types and sizes on the market. So in this blog I will do my best to make it simple to follow so you may hone in on the right filter for you.

The main reason we use filters in photography is to control the light as our camera sensor can't balance the exposure in a scene as well as our own eyes do. Using filters helps to equalise the amount of light between the foreground and the sky. The other reason I use them is to produce a slower shutter speed for a particular effect that I am trying to achieve. For example the fluid movement of a water fall.

Filters come in two different forms. The first is a screw in circular type and the second a square or rectangular shape that slides vertically into a filter holder which you attach to the front of your lens. The second option is a better choice because it allows the freedom to adjust the filter positioning to suit each composition.

 

 

 

The first filter I want to talk about is the Graduated Neutral Density filter, as seen above and below.

 

Neutral Density (ND) means that the colour of the filter is neutral and these are the kind that I prefer as I am not a fan of coloured filters that make an image look unnatural but that is a personal choice. Graduated filters are dark on the top half and clear on the bottom half. They are essential for sunrise or sunset images as the sky is always brighter than the foreground. The way that you use them is to move the filter up or down in the holder to match the horizon. By doing this you are darkening the sky and letting the camera capture more detail in the foreground, giving a more even exposure.

Like most filters the Graduated ND comes in varying tint grades ranging from 0.3 to 0.9

The higher the number the darker the top half of the filter is. From my experience it is handy to have a few different strengths but if you just want to dabble with one filter then I would recommend a 0.6. Many photographers, myself included, will stack two filters together to get the desired darkness, so get out there and give it a go.

The second filter I want to shed some light on is the Solid ND.

 

I use this type of filter on seascapes, waterfalls, etc. so I can still achieve a slow shutter speed for those misty looking watery captures when there is too much ambient (natural) light to get a slow enough shutter speed (see image below). This filter can also aid in showing cloud movement in the sky if you have the right conditions. For seascapes I usually shoot with a 0.6 Solid ND to get that movement in my images, and a 0.6 Graduated ND to balance the bright sky with the dark foreground.

 

Next, take a look at how we attach them to our lenses.

You have to decide which lens you will be using your filters on but that shouldn't be too hard as the most common lens for landscape photography is a wide-angle. Have a look at the front of your widest lens and see what size the thread is.

I shoot with a wide-angle lens with a 77mm thread size. That will dictate the size of the filter adaptor ring. The filter adaptor ring will screw onto your lens thread and then the filter holder connects to that ring.

 

Once you know the thread size, all you need to do is decide on how large the filters need to be. I suggest getting at least 100mm filters as they'll give you some room to move if you decide on getting a wider lens. If you are shooting a full frame camera then you may need larger filters.

Ok, so now we know what thread size our lenses are and how big the filters are we want to use. All we need to do now is select a holder to accommodate the filters.

 

You can purchase filter kits from many companies that come with the filter holder and various different ND filters. If you get one of these kits the only other piece you'll need is the adapter ring that screws on to your lens that we talked about earlier.

Here are two links that show the different kits that I would recommend.

LEE Filters Digital SLR Starter Kit

Cokin Z-Pro U960 Pro Graduated Neutral Density Filter Kit

take a look at the difference between these two shots that have the same settings but the first has no filters.

 

 

 

 

This really is the tip of the iceberg when it comes to filters but for my style of shooting these two types are indispensable. Happy shooting and if you have any questions, feel free to email me any time. Keep a look out for the next blog!