June 2012

Photographing a Water Splash

Pure, clean water is not as challenging to freeze in time as one might think. Once you understand how light is captured by your camera the process of capturing motionless objects becomes less challenging. In this short tutorial I will attempt to explain how the shot below was obtained using a SONY SLT A55V with SONY SAM 28-75 f/2.8 lens. Though I used a “fast lens” it is not a requirement since you will be stopping down quite a bit. But first the example photo:

Water Splash into Glass

The settings used for the above image:

Aperture: f/14
Shutter: 1/13
ISO: 200

Now the first question many will ask is whether I the shutter speed of 1/13th is a typo, but no, that is correct. But this is the simple secret many professional photographers will not share with you because it is a trick they figured out and hold on to. Here is how and why:

You will need a darkened room where, when you set up the settings as above and take a shot, you get a black photo. At ISO 200 a room needs to be pretty dark to produce an image which will be black at f/14 and 1/13 shutter, but it will not be so dark that you cannot see anything.

So how do we freeze the image?

The simple answer is, with light!

You obviously need at least 1 speedlight/flash which you can remotely fire from your camera. Since I use SONY equipment, I used 3 SONY flashes, a HVL-F42AM to light up the background (focused to 105mm to get the spot effect) and 2 HVL-F43AM flash units to light the splash. These units can be remotely (wirelessly) triggered by most of the Sony Alpha series cameras. The short burst of light from the flash unit is what stops the motion of the water, not the speed of the shutter!

The Secret Trick of Flash units!

Another rarely known fact of flash units (or speedlights or strobes) is that to produce higher power they produce a longer burst of light, not more power. At full power (1/1) a flash unit produces a longer pulse of light, not really a stronger light as many people believe. This is important to know as using your flash at full power will cause motion blurring as the pulse is long enough for motion to be captured and causing blur. At 1/16th power your flash produces a much shorter pulse of light which gives you less light to work with, but it happens so quick that motion is now almost non-existent! In the above case I fired the flash units at just 1/16th power to freeze the action. At 1/16th you are getting a burst of light equivalent to 1/8000th of a second or faster (which is faster than most camera shutters can be set to!).

Though I cannot vouch that this will work with other manufacturers, SONY owners can set up their scene with even just one, but preferably 2 flash units to the sides of the splash, wait for the drop and snap the shot. It does take some practice and perhaps a number of failed attempts, but once you get that one shot you will be amazed. The settings of aperture and ISO may need to be varied from camera to camera, but the principle remains the same. Remember that when you take a shot with no flash your resulting photo needs to be black.

Super Wide Panorama

I was contracted by a company to do some industrial photography of a work site where they we constructing a diamond sorting tower for a mining company. One of the requirements was to get a photograph of the construction warehouse and grounds. When I got up to the tower I soon realised that the whole warehouse and work area immediately in front of the warehouse would not fit into a standard photo, even with a wide lens. I did not want to lose detail in the image so I resorted to taking 14 photos using a tripod which I later stitched together to create a super wide panorama image. The only downside to creating such super wide panorama images from a high angle (the tower was over 30 meters tall!) is that the horizon would curve, but that was OK with me, and the client. The resulting image turned out pretty good. You can click on the image to view the full size image, but be warned, it is 15Mb in size.

Click for High Resolution Image (WARNING – 15Mb in size)

Image is copyright, Riaan Roux Photography (all rights reserved)

Lighting with a Flash

A flash, strobe or speedlight are basically all the same thing and produce strong light for short bursts in sync with your camera shutter to capture a photo. Flashes come in three main varieties, built into camera (or pop-up), flash unit (fits on camera) and studio flash (or strobe). I will attempt to explain how using a flash to light your subject will affect the appearance of your images. Studio strobes and flash units do not differ very much and produce very much the same light (for higher end flash units). Studio strobes are generally cheaper per unit than camera flash units, but you lack the portability as studio strobes require power outlets (and a pain to lug around). Photographers who, like myself, use flashes extensively in their photography are referred to as strobists.

Below is a series of images taken to show how flash lighting affects the subject.

Flash Lighting (click for larger view)

Pop-Up Flash

The pop-up or built in flash is horrible and there only as an emergency light source or people content with snapshots. A professional photographer will very rarely use a pop-up flash as it is mostly uncontrollable. Some professional cameras are not even fitted with a pop-up flash. When you do see a professional photographer using a pop-up flash it will usually be to trigger off-camera flash units which are signalled to fire by the light signalled from pop-up flash. In such a case the pop-up flash does not contribute to the lighting of the scene but merely send a type of Morse-Code to the other flash units. Pop-up flashes have a very short range (about 5 or 6 feet) and also create harsh shadows in the background (see above example). The subject is usually also flattened by the light and it tends to create hot-spots of light on your subject when closer to the camera. When the subject is a little further from your camera, pop-up flashes tend to under-expose the subject. Outdoors, when light is fading or when in shadow, a pop-up flash can be used to fill-in some light, but a pop-up flash should not be used as the only light source if you intend to do professional photography.

On Camera Flash

A on-camera flash is a step up, but hardly makes for professional photos when constantly pointed at your subjects. An on-camera flashes pointed at a subject produces only good looking snapshots which are OK for the hobby photographer. On-camera flash units are normally fitted with a diffuser panel to soften the light a little and thus creates softer background shadows (see example above). On-camera flashes still flatten features of a subject by killing all shadows on features facing the lens. Shadows are your friend when you learn to control light and, when dropped to the sides, they create depth and dimension to your photos. When professional photographers use an on-camera flash they will do so only to fill in shadow areas without lighting too much (killing the shadows).

Bounced Flash

Your flash is still on your camera, but now you tilt it up to the ceiling or towards a wall or other white surface and bounce the light. Bounced flash, as in the example above requires a ceiling, wall or other white surface from which the light of the on-camera flash can be bounced. This give a more natural look and feel to photos, but it does have its own drawback in that it is tricky to learn to bounce the light correctly without adding unwanted spectral light. Some flash units are fitted with a bounce card (white piece of plastic which pulls out behind the flash head) which can be used as a bounce surface when no other surface is available (like outside or building with very high ceiling). The bounce card can also be used even if you use a ceiling or wall to bounce light to allow more light to be directed forward, but this should be experimented with extensively to learn to apply correctly and avoid the “snapshot” look. The biggest advantage of bounced flash light is that you effectively kill distracting background shadows. The disadvantage is that your flash light will pick up any colour from the surface it is bouncing from and add it to your subject. If you have a red surface you subject will get a red cast. Bouncing also requires that your flash work twice as hard producing the light as it needs to travel further and this will eat your batteries.

Off-Camera Flash

If you use a flash unit on a stand triggered by a wireless transmitter (radio or optical) then you start to enter the world of professional photography. You can now control how much light you want on your subject and how much shadow you want to create to enhance features or create depth. You can also start to use light modifiers to soften or enhance the light. In the above examples a flash unit to the left was used first with just its diffusion panel and then with a silver umbrella (also known as a broli or brolly). There are many types of light modifiers from beauty dishes, soft boxes, grids, snoots and umbrellas (reflective or shoot-through) which you can use. In the above example the silver umbrella produces a slightly more pronounced light adding a look of drama to the subject.

But lighting with a flash does not stop there. In the above examples the background is actually supposed to be white, so why is it greyish? Well, the simple answer is that the background is not getting enough light. Without getting into the technicalities of the inverse-sqaure law of light which explains why light drops off three times as fast for every double in distance, just accept that the light you are providing for your subject is never going to be enough to light up a background as well when it is further from your subject. If you attempt to light the background and subject with just one flash unit your subject will always become serious over-exposed (unless the subject is standing against the background). To make a background white you need another flash unit (or even two depending on the evenness of light you need). In the second-last image just 2 flash units were used which is already producing a professional looking photo, but it does not stop here. The shadow side of the subject has a dark look to it and pulls focus towards the light. To balance this we add a 3rd flash unit to create a rim light on the right of the subject. The darkness has been lit up and the light focus is now centred on the subject. Study more images in magazines, on the internet and even in television programs and note how many (if not most) have this sneaky rim light somewhere on a edge of a subject just to give it that little balance.

In the professional photographers’ kit you will always find a high quality flash unit, and a professional strobist will always have 2, or 3 or 4. I never leave home without at least 3 flash units in my kit bag. Flash units are expensive, at a cost of R3000-R4000 each for higher end units, but once you learn to control light with multiple units you find it hard to turn back.

Happy strobing!

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