Shutter Priority, Aperture Priority … or Programme Mode? Which should I use??
Probably the single question I'm asked most by people keen to improve their photography is "How do I move on from using the Program or Auto mode on my camera"; "What settings should I use".
Wildlife photography is a challenging branch of photography that can test your skills to the limit and often in very difficult lighting conditions etc. So what is the magic exposure formula to getting those razor sharp images that can stand out on the pages of Africa Geographic? It seems everyone has an opinion and in many respects, for the aspiring photographer new to the world of a Digital SLR it can be very intimidating. I'm asked the question countless times and I feel the frustration sometimes of new photographers who believe there is one specific mode that satisfies all occasions. Afraid not, but that doesn't mean it's going to get complicated, all you need is to apply a bit of foresight about what image effect you are tying to produce, and the "behaviour" of your subject matter, and you've nailed it!!
So how do I approach my own photography? Getting into a good routine (see my last blog post) and thinking about the image you want to create is a good first base. First off, I set my ISO to account for the available light is the first stage .... these days cameras are more than capable of operating with very little loss of quality at incredibly high ISO settings, therefore I rarely shoot on less than ISO 800 when doing general wildlife photography. For static Landscapes and Macro I shoot much lower, say ISO 100 but this will increase the requirement to use a tripod as the shutter speed will reduce considerably at these settings, making hand held operation almost impossible. Generally, I like to control the level of background blur (Depth of Field) in my images so Aperture Priority is the way to go. In the image above of the Chobe elephants in Botswana, what was key to the images after getting the grouping of the elephants correct, was ensuring sufficient Depth of Field so that the back ground would remain in focus, yielding a nice sharp image from front to back of the picture.
n circumstances where freezing action is required, particularly with birds in flight, Shutter Priority is selected to ensure the camera adopts fast enough shutter speed to render the image razor sharp. The Fish Eagle image below was shot from ground level on the Biyamiti River in the Kruger National Park. The critical element here was freezing motion, both with the bird in flight and also the effect on the water droplets. I used a shutter speed here of 1/1600th sec and an aperture setting of f4.5, hence the blurred background in the image.
So what about that Program or Auto Mode? Is it really as taboo as many people make out? .... Well in essence there's nothing wrong with it at all. It is often the mode most beginners start with and many stick with it. In fact I know a good few professional wildlife photographers who use it whenever they can and many of you will have their books on your shelves at home!! But there is no way it can do the best job possible in every situation. My cameras have a "flexible" Program mode that allows me to override the camera's choice of aperture and shutter speed before shooting. In essence I can vary the effect on the depth of field (changing aperture) or motion sharpness (changing shutter speed), but the camera remains constant in the level of exposure applied to the image. If you push the shutter speed up one stop faster, it will automatically compensate by opening up the aperture one stop to keep the exposure the same. You know, some folk believe there is a stigma attached to using Program Mode since its use gives so much control to the camera.
My view is that it's "part of your tool bag". Knowing when to use it, and also knowing when to take control of the camera yourself and thus understanding the dynamic between aperture, shutter speed and ISO setting, is a technical aspect of photography that is worth spending some time experimenting with, and gaining a better understanding on. You will expand your creativity immensely and your images will improve beyond recognition. There really is nothing wrong with Program Mode. While it doesn't provide as much control as other exposure modes, that control is only useful if you know how to use it and have the time to do so. Remember, if you've spent $1000's on your new digital camera, you've acquired a machine with a very sophisticated metering capability .... so use it!! That's exactly what you are doing in Program, Aperture and Shutter priority mode.
so where should you start? .... Well Shutter Priority and Aperture Priority is the way to go at first. Here you can dial in your aperture setting and be sure that the camera will select the right shutter speed automatically, to give you a correctly exposed image. It's effectively a "semi automatic" function, giving you some control but the camera is still working with you to get the right quality result. Conversely, in Shutter Priority, the reverse is true. You pick the shutter speed to either freeze motion or intentionally blur it, and the camera will select an aperture to make the exposure come out what it feels is correct.
Finally, we can't overlook Manual Mode, which for many experienced photographers is still the best way to get the desired effect. However, in order to really succeed in this mode you really have to have a good understanding of the fundamentals surrounding aperture, shutter and ISO and the inter-relationship between these three variables. These days with the benefits afforded to us all in with digital cameras, we can still see the effect in terms of under / over exposure via the viewfinder or rear LCD display. So I guess even Manual Mode has got a bit more help from the advancement of camera technology!!
My advice is to get out, take images and learn from your mistakes .... but remember, there are only prizes and plaudits for great images ... you get no prizes for the settings you use!! So if you find an approach that works for you, stick with it, understand it's limitations and then understand what you need to do when your subject or lighting conditions change. Now you have mastered the use of exposure modes on your camera .....