Tuesday, November 9, 2010

Tech Talk Tuesday - Flash Photography

As per several requests, I'm going to talk about the basics of flash photography on today's Tech Talk.  WAIT!  Don't click to the next blog on your blog list just yet!  I promise this will be even simpler than the basics.  I know many photographers are clueless about how to get decent photos when using an on camera flash so they stick to only shooting during the day.  It is true that natural lighting, IMHO, is the prettiest, most desirable light for photography, but that really limits when, where, how and what time you can take pictures.  Using flash will give you more photo opportunities and more chances to be creative.   Learning to use a flash takes some time and practice, but is well worth the effort, because you will certainly improve the quality of your photos when you understand some of the basics.  

If you have a point and shoot with a built in flash, your options are limited.  You can, however, see if you have a control that will allow you to decide when to use the flash rather than letting the camera decide.  For example, if you are shooting a dark and mysterious scene and you want it to look that way, your camera will still think the scene is underexposed and will flash, ruining the desired effect.  Or if you are taking a portrait in bright sunlight, your camera will not flash, but what if you want to add a little fill flash to brighten up the shadows under your subject's eyes.  If you can control when the flash goes off,  there are some options for point and shooters.  The trick is to know exactly what your camera will allow you to manually control.

But this post will be mostly for those of you who have a dedicated flash that you can attach to the hotshoe of your SLR camera.  First some basics about using any kind of flash.
  • Normally a flash on your camera will produce a harsh, unflattering light
  • Often a flash on your camera will cause people to have devil eyes (red eye)
  • Often a flash on your camera will create unwanted shadows everywhere
  • Remember that a flash will only light up a short distance  (it always strikes me funny when I'm at a stadium at night and thousands of flashes go off.   I really wonder if these people think their flash is lighting up the field below)!
So the first thing to know about using flash, is how to set the controls on your flash.  I will only show you the very basics, because remember, my posts thus far are for beginners.  I use Canon equipment and this is a Canon Speedlite 580EX II, so I hope all you other camera users can adapt this discussion to your flashes. 

First you need to decide on the "mode" you want to use.  "ETTL" means the camera senses the scene and makes the exposure/flash decisions for you.   "Multi" means that you are using that particular flash in conjunction with 1 or more additional flashes.  "M" means you are shooting in manual and you decide the flash output.  To set the mode you just push the mode button (3) and with each push, it cycles through the three options.  Here (1) it tells me that I'm in ETTL mode.

After you decide on a mode you can then fine tune the flash output by increasing it or decreasing it.  First you push the button in the center of the wheel (4) and then turn the outside wheel (5) clockwise to increase output in 1/3 or 1/2 increments, or counter clockwise to decrease.  The numbers on the LCD screen will flash until you push the center button again (4), which saves your settings.  In this picture I have set the flash output to increase by +1 (2).  You can fine tune the flash output like this in all the modes.

With this kind of sophisticated flash unit there are tons of additional settings to learn and use, but this post is to get you started, and too much information is confusing.  Just with the above basic information, you can use your flash in almost every situation.  My advice for beginners is to put your flash in ETTL mode, take a test shot to see if the camera can get the flash output correct.  If it needs to be fine tuned for a little more flash, or a little less flash, then fine tune as described in the above paragraph.  You may never need to know any more than this to get the perfect amount of light out of your flash.

(One addition bit of useful information to note, is the numbers at the bottom of the LCD.  Depending on your settings and lens, you will be able to see the maximum distance an object can be to be properly lit by the flash.)

Second, you need to learn how to make your light pretty.  Photographers spend a lot of time trying to make artificial light look natural, and with pleasing shadows in just the right places.

Because most flash light is harsh, the first thing to consider is buying some sort of a modifier to attach to your flash.  They come in all sizes and shapes, from simple to elaborate, but all have the same purpose - and that is to soften the light.  In addition to this, often photographers will attach colored cellophane type paper to the flash head to imitate the type of light they are looking to achieve.

Another way to soften light and make the light more flattering, is to not point the flash directly at your subject.  If you are indoors, turn your flash head to the ceiling or to a nearby wall, and 'bounce' the light back onto your subject.  This will broaden and soften the light and take away the 'deer in the headlight' look, and create nice catch lights in the eyes.  It will also help to avoid hard shadows on the wall or whatever else is behind your subject.

Speaking of eyes, one problem with flashing light straight at the face, is that it often creates red eye.  Most cameras have settings to reduce if not eliminate this problem, but often this is at the expense of a delay in the shutter opening and closing.

One way to avoid red eye, and to take more flattering portraits with nice shadows and shading, is to take the flash off the camera and have the ability to move it away from dead center above the camera.  Some photographers use a bracket which solves both of these problems.  This, however, only allows the flash to be off center by a small amount. 

When you are really ready to 'rock' with off camera flash, you will invest in some nifty little radio transmitters called Pocket Wizards.  You attach one to your camera and one to your flash.   Then you have the freedom to stick your flash on a stand and move it anywhere you want, independent of where your camera is.  This gives you the freedom to see where your shadows are and the ability to create beautiful light.

This is just the start of learning how to use flash to give you more versatility in creating lovely lighting for your pictures.  Maybe you should give it a try!!