A landscape image needs to be more than just a record of a place visited, it is a combination of seeing, patience, light, technical competence and finally a little luck.
You are the creator, your composition is your personal vision of the world. It may be a sweeping landscape or simply a small element within it, you will decide to include or omit as much or as little of the scene as you choose. However, what we see outdoors and what ends up on our computer screen or in print may not necessarily be the same thing. The process of taking the image requires skill and an understanding of exposure to maximise its full potential.
1. What is exposure ?
Exposure is one of the most important aspects of photography and essential to the principle of photographic knowledge. We must move away from the auto settings on our camera if we want to really master exposure, exposure is controlled by 3 things – the relationship of ISO rating (sensor sensitivity), the aperture and the shutter speed. It is this relationship that controls the exposure.
Although simply a relationship it is the essence of photography and dedication to understanding the principles of exposure is time well spent. ‘Correct’ exposure is really a misnomer, we are aiming to record an exposure that accurately reflects what we see and feel. If it is darker or lighter than we intended it to be then we have failed to fully master exposure.
2. What are the practical considerations ?
I do most of my landscape photography from a tripod, this holds the camera solid, ensures a considered composition and allows a small aperture to maximise depth of field to be used. As we are using a tripod we can use a slow ISO setting, say ISO 100 to produce an almost noiseless image. I would select this speed for 90% of my landscape work. With the ISO speed set we can now look at the relationship between the aperture and shutter speed. Remember changing one will necessitate changing the other to maintain this relationship.
Depending on the subject matter there are choices to make. If we want pin sharp from foreground to infinity we will need a small aperture, a large f stop number. If the converse applies and we want to isolate a tree in the foreground and render the remainder of the image out of focus we need to select a large aperture, small f stop number. These examples are extremes at either end of the f stop scale, reality states that we should use the most suitable f stop to record the image as we wish.
By selecting Aperture Priority on the camera controls we are allowing the camera to select the shutter speed to match our preferred f stop. We can of course over-ride this by adding or subtracting light via the use of exposure compensation to make the image lighter or darker. This is entirely under our control, the camera nothing more than a tool to complete the job in hand.
3. What are the limitations ?
Our cameras digital sensor can record up to 6 to 7 stops of contrast (dynamic) range whereas our eyes can distinguish a contrast range of about 14-16 stops of light, more than twice that which our digital sensor can record. It is important therefore to ensure that the scene is contained within the contrast range of the camera. If it cannot then we run the risk of either blowing out the highlight detail or blocking up the shadow detail. With this in mind we need to try and visualise a scene the way our camera will record it. If your camera has a built in spot meter or you have a hand held spot meter then it can be used to measure the extremes from light to dark (IMPORTANT : NEVER POINT YOUR CAMERA DIRECTLY AT THE SUN – IT WILL BLIND YOU IN AN INSTANT – YOU HAVE BEEN WARNED!).
If the contrast range exceeds 6 stops we can either use a neutral density graduated filter to lower the contrast of the sky or alternatively we can blend two differently exposed images in Photoshop.
4. What next ?
Phil offers Landscape Photography workshops, these are primarily field based and aimed at beginners and improvers who are looking to enhance their skill and technique. If you require further information please visit Isle of Mull Photogrphy Workshops
