PHOTOGRAPHING THE ELEMENTS

Transcription

1 PHOTOGRAPHING THE ELEMENTS PHIL MORGAN FOR SOUTH WEST STORM CHASERS

2 CONTENTS: The basics of exposure: Page 3 ISO: Page 3 Aperture (with examples): Pages 4-7 Shutter speed: Pages 8-9 Exposure overview: Page 10 Lightning: Page 11 Snow: Page 12 Rain: Page 12 Waves: Page 12 Rainbows: Page 12

3 UNDERSTANDING EXPOSURE THE BASICS What is it? Exposure is, in its simplest term, brightness. When you press the shutter button half way, you will notice a meter is displayed when you look through your viewfinder. Think of this as a brightness indicator. Varying on the situation, your aim will be to get the small arrow (or small line) to sit in the middle of this meter. Anything left of this and the image will appear darker, anything to the right and your image will be brighter. How you control this meter consists primarily of three variables which are often referred to as the exposure triangle. These are ISO, shutter speed and aperture. ISO ISO is the most basic element to understand of the exposure triangle. This controls how sensitive your camera is to light. Usually, image quality decreases as the ISO increases. I tend to only ever go to ISO 800, however most modern cameras can go much, much higher before the quality becomes a real issue. This quality degradation I refer to is noise or grain being displayed on the picture. Should I need to make my picture brighter, the first thing I check is my ISO. Providing I keep at or below 800, this is the easiest setting to change whilst still giving me creative flexibility.

4 APERTURE Aperture is the hole in your camera which light travels through in order to get to your sensor. This is displayed as an f number on the screen (for example f1.8). If this is set to a small number, the wider the camera hole, thus more light can reach the sensor resulting in a brighter image. The effects of aperture are not just centered around image brightness, however. It also controls depth of field (examples are included below.) Depth of field is how much of the image is in focus. Picture one: Aperture 5.6 With the aperture set to 5.6, you can see that not all of the flower is in focus. Watch how this changes as we change the aperture. Picture two: Aperture 8 Moving up to 8 brings the flower into a bit more focus.

5 Picture three: Aperture 11: Progressively, less of the flower is blurred, and more becoming focused. Picture four: Aperture 18 Picture five: Aperture 25

6 And finally Aperture 32 Aperture 5.6 Aperture 32 Portrait photography usually uses a small f number in order to create a blurred background. In contrast to this, landscape shots are normally between f8 and f16.

7 Uses a smaller f number to blur the fence in the background Uses a larger f number to keep more of the shot focused

8 SHUTTER SPEED Shutter speed is how long the shutter of your camera stays open. The longer it stays open, the brighter the image. More often than not, it is best to use a fast shutter speed for moving objects. This ensures that the image stays sharp, and freezes the action. In contrast to this, a slow shutter speed blurs any movement. This technique is used for creating light trails, and also used frequently in astrophotography. A fast shutter speed and flash freezes the action of this BMX rider In contrast, a slow shutter speed blurs the motion of these car headlights

9 The problem with using a slow shutter speed is blur. Anything less than 1/100 will require a very steady hand. This is about as slow as I go before I use a tripod, unless circumstances dictate differently. For long exposures like that of the light trail above, a tripod is essential for a clean, blur free image. It is a common misconception that fireworks need a fast shutter speed to freeze the action as they explode. However, using a slow shutter speed captures the light and movement of the explosion - often capturing more than one explosion within one frame. The shot above uses a slow shutter speed to blur the motion of the traffic. By mounting the camera on a tripod, the rest of the shot was kept sharp due to the camera being kept steady.

10 EXPOSURE THE OVERVIEW Now that we have gone through a few examples and a brief explanation, here is what it all boils down to: ISO: controls the camera sensitivity to light but can decrease image quality if increased too high Aperture: controls depth of field and brightness Shutter speed: is how long the shutter is open. Fast shutter speeds freeze motion, slow shutter speeds blurs it. This star shot taken from Dartmoor National Park combines all of the techniques described above. I used a low F number in order to enhance brightness, and ISO of 800 (again to increase brightness) and a slow shutter speed of 15. Anything above ISO 800 would result in a grainy image, and anything slower than 15 would result in the stars trailing due to the rotation of the Earth.

11 PHOTOGRAPHING THE ELEMENTS The most important thing in any type of photography is to be aware of your surroundings. Do not put yourself in danger for the sake of a picture. Lightning: I have been fortunate to be able to capture lightning on camera on more than one occasion. With these techniques, you can greatly increase your chance of getting a shot of a lightning bolt. My first piece of advice would be to invest in a tripod and a remote trigger release. When taking lightning pictures, I always do it from the safety of the house, where there is less risk of being struck. With the camera on the tripod, adjust your settings so that you can get a slower shutter speed (whether this be by lowering your ISO or making your F number higher). Then attach your cable release and lock it, so that it keeps on taking picture after picture. I would recommend doing a few test shots to see how bright / dark your image comes out, and adjust settings accordingly. By having a slower shutter speed, you are more likely to capture lightning, as it eliminates the difficulty of trying to press the shutter button on the exact time of a strike. The next piece of advice that I would recommend is to use a wide-angle lens or if your camera has a fixed lens, make sure it is zoomed out as far as possible. This will increase your chances of getting lightning in your frame, rather than hoping it will hit a specific location. If you are using the camera at night and have nothing to focus on, switch to manual focus and align your focus ring with the infinity symbol (which looks like a sideways figure of 8).

12 Photographing snow Snow photography presents a different challenge. If you are hoping to capture falling snow, using a flash and/or fast shutter speed with freeze the movement of the snow falling. If, however, you are aiming at capturing the snow on the floor, the most helpful advice that I can give is to use your exposure meter. Look through your viewfinder at the snow, and make sure the meter is correct for the snow. If your picture comes out too dark in other parts of your image for example a tree in the foreground, you can correct this later in editing. You can always recover details from shadows more easily than recovering details from overblown highlights. Photographing rain / flooding / waves This is the same principle as falling snow. A flash and / or fast shutter speed will result in rainfall being picked up by the camera. This will also allow you to freeze the motion of waves crashing. However, once again it is vitally important to be aware of your surroundings. I have seen so many close calls with photographers being caught out by a huge wave! In order to get the blurred water effect, you need to have a lower shutter speed. You can do this by selecting a higher F number, and by lowering your ISO. Rainbows Have you ever taken a picture of a rainbow only to find out it is hardly visible in your picture? Here are a few tips to help. First of all, use a higher F number. This will allow you to get more of your shot in focus. Next, use a tripod. If your aperture means you have to have a slow shutter speed, this will help you to prevent any blurred shots. Finally, if you have one, use a polarizing filter. This will help to reduce glare / reflections, and will allow your rainbow to be more saturated.