Flash Photography
Introduction to Flash Photography
Welcome to our introduction to flash
We’re going to talk about the different flash units available, how they work, and the advantages and disadvantages of each type of flash. A flash is an indispensable tool, and it’s not too complex or difficult to learn.
How to Get Started: Professional Tips on Flash Photography
Why Learn about Flash Photography ?
The answer is simple – learning how to use your flash properly can radically change your
In this lesson, we’re going to learn about the various types of flash units on the market, their strengths and weaknesses, and how to select a flash that meets your needs.
Pop-Up Flash
Most DSLR cameras have a small built-in or pop-up flash. When your camera is set to fully automatic, it will determine whether there is enough light. If there isn’t enough light, it will pop up the flash automatically.
Red-eye
Most built-in pop-up flashes are located near the camera lens, so the light points directly to the subject. Often this results in red-eye, especially under low-light conditions. Red-eye is common with pop-up flashes because pupils usually dilate when you use a flash in ambient low-light conditions.
Red-eye occurs when light from the flash is too fast for the pupil to close, so the bright light from the flash passes into the eye through the pupil, reflects off the fundus in the back of the eye and out through the pupil. The result is subjects with red eyes. The good news is there is a solution! Using a flash source off-camera or from a different angle will help eliminate red-eye.
Speedlights
An on-camera flash, or speed lights (sometimes called strobe lights), provides additional light when you don’t have enough available light to properly expose your photograph. These shoe-mount flashes mount easily to the top of your camera, or they can be held off-camera using a sync cord.
Speedlights run on batteries, and the higher-end units have an option to connect an external power source for improved performance. Most camera manufacturers offer a range of optional external flash units that are compatible with your specific camera. Most of these units have rotating heads that move left-to-right and up-and-down. So you can bounce the light off a wall or the ceiling using an external flash to enhance the quality of your photo.
This is an important consideration with smaller cameras that do not have automatic exposure control, like the two bottom cameras:
Smaller “point-and-shoot” cameras have flashes with non-automatic exposure control and very small flash units. So their range is quite limited. Usually, they are ineffective after 15-20′.
Most serious photographers use flash units with automatic exposure controls (ranging in price from $50 up to hundreds)… typical circuitry (called thyristor circuits) has the ability to continue to pour light onto the subject – and back to the camera – until the exact exposure is accomplished even if the flash is not pointed directly at the subject matter.
These strobes have a wide range of power settings to use – usually from Full power to 3/4 to 1/2 to 1/4. You can tell what aperture to use by checking the settings dial (r) or, on newer strobes, an LCD Control Panel on the back. Using Full Power drains the battery rapidly, so you should normally use a lower setting.
I stick with 1/2 power for most work, and that is plenty. According to the dial – after I set in the film speed (f400) at the bottom, I see that I need to set the sensor on the front of the strobe to red (1/2 power) …. and, RED= f8.0 …. and that is the aperture setting I would use whether I am aiming the strobe straight at the subject or not. Have a read of our flash shutter speed article to get familiar with other handy tricks and tips.
Here is why you would NOT point the flash directly at the subject. If you shoot “straight-on”, you run the risk of washing out skin tones, eliminating texture, creating harsh shadows, and getting “red-eye”. But, if you want to soften the light and spread it out, and eliminate shadows, you should lift the flash off the camera and aim it… I aimed the flash at the girl in the background, and the light spread evenly from the foreground to the back.
Also, moving the flash to one side will bring out the detail and texture of the subject and help you avoid harsh shadows in your photography.
Bounce Reflector
Even better…. use “bounce light” whenever possible. Aiming the light upwards will bounce off the ceiling and spread out softly, giving you much more balanced lighting and no harsh shadows. There are times outdoors when shadows may require “fill light” from a flash. However, backlit lighting can be pleasing…. here, I opened up two stops from the normal daylight exposure.
At other times, outdoors, the shadows may be intrusive and offensive, and you should use flash to fill in the areas of the subject covered with shadows. Here I had to make the exposure based on the fact that the maximum shutter setting for flash is 1/125th … so I took the flash off automatic – thus giving me full power and set the aperture at f22.
Now let’s take a look at some accessories designed to take the harshness out of flash
The flash on my trusty, old Ricoh “point-and-shoot” camera was powerful enough, so I placed some Mystic tape over the flash head to reduce the harsh light. Instead of paying $40-50 for a factory-made diffuser for my Vivitar strobe … I cut off the end of a small plastic bottle (made of translucent material) and taped it on the head. Works great!!!!!
Again, for those of you on a budget, there is no need to kick out $40 for a reflector card…. when you can simply use a piece of white plastic. It works every bit as good as the factory-made options….. and you could use colored plastic to introduce off-colored light!!!
Finally, there are some accessories you should consider buying…. an extension cord which will provide a high degree of flexibility in the way you aim light…. and a remote sensor that will make a second strobe a slave unit.
Inverse Square Law
what exactly is a slave unit and what is it used for?
Thanks
Rich
A slave unit is a flash that is not actually a part of the camera. It is not internal and it is not connected in the hot shoe. They often have an optical sensor that triggers the flash when the flash on your camera fires. There are more highly developed systems out there that are more commonly in studios where you can basically connect a remote control to your hot shoe and have all your lighting fire based on that remote control trigger. Slave units are incredibly useful as often times you want light sources from more than one angle.
Thank you for sharing the wonders of trying to create great pictures. The lessons were informative and even as the film camera era is eliminated the information you shared will make those in of us non photographers in the digital era more aware of the art and science of capturing a picture that is worth a million ahhhs.
We will always need the real photographers.
Thank you
Just for future readers Light level decreases in defined formula. The formula goes something like 1/distance^2 also known as the inverse square. basically if you double the distance you quater the light, triple the distance and you take the level of light to 1/9th that of the original distance.
Your posts are really educative for beginners!
What kind of flash would you buy to add to a Olympus E-510?
Your web pages are great, but you could help the reader to follow your explanations more easily by writing ‘above’ or ‘below’ when referring to images.
So I’m guessing that this isn’t for beginners? I kinda just clicked because I’m getting a new camera for my birthday and I’m beginning out.