Thanks to wildlife and landscape photographer John Dominick for his lesson and photos.
Along with volunteer warden Andy Jones I have been co-leading photography workshops at Pulborough Brooks for four years. They have proved to be very popular with all levels of photographers, especially because of the abundance of subject matter that the surrounding habitats have to offer. They are founded on a desire to bring participants a memorable experience whilst interacting with our natural world. Very much based on creativity we believe that some degree of technical knowhow is necessary to unleash that artistic expression as well as securing the best possible record of wildlife and landscape, depending on your ultimate ambition.
With this in mind and due to us being unable to run workshops this year we thought we’d put together a series of posts on some of the things we cover with participants. Future articles will be more creativity based but to start with we thought it may be appropriate to write about some of the basics of image-making.
The term “exposure triangle” is often used to help explain the interplay of the three main elements involved in obtaining a correctly exposed image. By this I mean neither too dark nor too light in appearance. These three parts are:
Time (shutter)
Light (aperture)
Sensitivity to light (ISO)
They are all linked in that if you change one of them it will alter how the brightness of your image is rendered. Of course, you can set your camera to AUTO and it will mostly produce a perfectly exposed image. This is useful but there are times when you may want to take more control over the final image especially in relation to how much of your image is in focus, depth of field as it is known.
For landscape and close-up photography, we mainly want as much of the image in focus as we can achieve. Therefore, we will use smaller apertures in the region of f/8-f/16. As you can see in the diagram above we refer to these as smaller apertures as they produce a physically smaller hole in the iris of the lens. However, because this hole is smaller less light is reaching the cameras imaging sensor, potentially rendering a darker image. Therefore, we have two choices to correct this. We can increase the amount of time of the exposure using our shutter speed to make the image brighter or increase the light sensitivity by increasing the ISO. We can also use a combination of the two, this is especially useful if we want to keep the shutter speed higher to ensure our images are not blurred by camera movement. Increasing the ISO can introduce grain, or “noise” as it is known, so there can be payoffs but generally I would rather have a sharper image than a blurry image, so I am willing to accept this.
In the heathland image below, I have used a small aperture of f/16 to ensure the maximum image sharpness, depth of field, throughout the image. Because I wanted to record the ultimate detail, with no grain, I chose to set the camera to ISO 100. This resulted in a shutter speed of 1/10th of a second, which was too slow for me to handhold without blur, so the camera was mounted on a tripod.
Sometimes we need to ensure a shutter speed that is high enough for handheld imaging whilst ensuring the maximum detail. In the image of the Marbled White below, I needed to use an aperture setting of at least f/8 to ensure enough depth of field to obtain sharpness in the wings. I knew I could handhold the camera to 1/160th of a second without blurring and so had to set the ISO setting to 800 to achieve this. Anything below this and the image would have been rendered too dark or my shutter speed would have dropped too low. This didn’t give me a completely grain free image but it was very acceptable, as indeed are most modern SLR cameras up to ISO 3200 and sometimes beyond. Especially with use of editing software.
Applying the relatively principles of exposure variables and learning when to sue them to best effect will bring great leaps to your photographic experiences. It will give you confidence in your abilities which will reflect in your creativity and lead to more experimentation and expression.
As mentioned there is always the fallback of “intelligent auto” modes if this is all too much to remember and there is nothing wrong with using this. Chances are the camera you are using is full of technology and these modes are using algorithms that will choose the best settings based on what the processor perceives you are pointing the camera at. You can load the dice in your favour further by choosing one of the various modes such as theses listed below;
Sport, for fast moving and action photography, particularly wildlife. This will bias the settings to a higher shutter speed and adjust ISO and aperture accordingly.
Landscape, which will have an emphasis on increased depth of field and therefore use a smaller aperture, usually about f/11.
Portrait, this will usually use a wider aperture to bring less depth of field and render the background as out of focus.
Beyond these are the more advanced modes of shutter priority, aperture priority and fully manual as well as advanced exposure metering. These will be covered in the next blog along with an introduction to composition techniques.
I hope you have found this article useful and it has given you an insight into the depth of knowledge that is available on one of our workshops. Nothing can beat being out in the field putting theory into practise and we are very committed to providing just that. We hope to be able to welcome you to our workshops in the not too distant future.