As with most other kinds photography, I see the creation of good landscape and travel images as a three stage process, with each stage involving a series of individual steps. This is my approach:
When I see a situation I feel has the potential for a good picture, I have a very quick conversation with myself - it goes something like this:
Having already previsualised how I’d like the image to look, the technical decisions about how best to capture the image are made so much easier.
I’ve already decided what I want to photograph, where I want to photograph it from, which Lens (focal length) would be best and whether a small, medium or large aperture would achieve the look I want for the background.
If the ideal lens is not already on my camera, I’ll quickly change to the right one - Quickly, because situations and opportunities can and do change very quickly.
Most of the time I leave the mode set to Av, (meaning "aperture value") When I’m using this mode it’s the combined effect of my selected aperture, ISO setting and the light intensity that determines my shutter speed.
The actual speed is rarely critical, so long as it’s fast enough to overcome any camera shake and arrest any subject movement. If I’m shooting fast action I’ll sometimes switch the mode to Tv, (meaning "time value"). In this mode it’s the combined effect of the shutter speed, ISO and light intensity that determines my aperture. In action situations the aperture settings tend to be of less importance. To my mind it’s more about arresting the action of the subject itself and less about how much else is in sharp focus.
If the light is sufficiently bright and my subject isn’t moving too much I prefer to leave my ISO (light sensitivity) on its lowest setting, (on my camera that’s 100). You get the best image quality your camera can deliver when it’s set at its lowest ISO. Higher settings progressively introduce digital noise. However, there are lots of situations where you have no choice but to use a higher ISO.
If I’m shooting a scene in low light and I want good depth of field, a longer than normal shutter speed is often needed. Typically I’d use a tripod, but if I don’t have one with me, or it’s not convenient or legal to use one, I have no choice but to set a high ISO. The image will be noticeably grainer (noisier) than if I’d used a tripod and a lower ISO, but at least I’d have a picture.
Sports photographers shooting fast moving action have to use high ISOs, especially in low light. When press photographers are barred from using flash, high ISOs are their only option.
Composition, more than any other thing is what makes images stand out from the crowd. Here are some of the things I think about while I’m looking through the viewfinder before I press the shutter.
When our subject is one specific thing, like a person, the answer is simple - "on their eyes". The sharpness of the rest of the face is important, but less so. But if our subject is a scene we are usually dealing with depth, as in front to back depth, and need to consider our "depth of field" (or "depth of focus") ... i.e., how far in front and behind the point we focus on is to rendered sharply.
This in turn is controlled by our choice of aperture, the smaller the aperture, the greater the depth - also where in the scene we choose for precise focus.
In most cases I’m not looking to stop action, but when I’m hand holding my camera, which is most often the case, I need a shutter speed that’s fast enough to overcome the effect of any camera shake. The longer the lens, the faster my shutter speed needs to be.
There’s an old rule of thumb that says: When you’re hand holding the camera your shutter speed needs to be at least equal to the focal length of the lens you’re using. For example: If you’re shooting with a 100mm lens, your shutter speed should not less than 1/100th of a second.
The advent of image stabilization has made it easier to shoot at slower speeds, typically at half or even a quarter of the focal length, without degrading the sharpness due to camera shake. However, we also need to be mindful of subject movement, a problem that even clever technology cannot fix.
Am I 100% happy with composition as it currently appears in the viewfinder?
Have I overlooked some small annoying element near the edge of the frame?
Should I change my composition slightly to eliminate it, or will I live with i\any small problems for now and clone them out once I get it into Photoshop?