Lesson Seven: The Sharpness Triad, Part III

So you've opened the aperture as wide as you can and you've set the appropriate shutter speed and you still can't get a sharp picture.  What can you do?  Well, as a last resort, you can try increasing the ISO.  What exactly does that do?  Well, it increases the sensitivity of the camera's sensor to light so you don't need to open the aperture as wide or keep the shutter open as long.  So you're probably asking yourself if it can do all that, why not just shoot constantly in the highest ISO your camera can shoot?  Well, it turns out that the higher the ISO (i.e. the more sensitive the sensor is to light), the more grainy the picture turns out which is not always a bad thing especially if that is the kind of look you're going for and, of course, a grainy picture is better than no picture at all.   

Lesson Six: The Sharpness Triad, Part II

Last time we talked about aperture which is the first part of the sharpness triad.  If you've tried to open your aperture to its widest setting and still can't get the picture sharp, the next thing you can try is to adjust the shutter speed.  Here's the way the relationship between aperture and shutter speed works.  The bigger the aperture, the less the amount of time the shutter should have to remain open to let enough light in to get a sharp picture.  Here's a little experiment you can try at home.  Set your camera mode to shutter priority (Tv mode).  Now set the shutter speed to it's fastest setting which should be 1/x second where x is a number.  You want x to be the largest number on your camera.  Go ahead and take a picture.  Now change the shutter speed to the second fastest setting.  Take the same picture.  Now keep doing this, decreasing the shutter speed.  You should notice that as the shutter remains open longer, the picture will get brighter up to a certain point where you'll start noticing blurry pictures (usually when the camera is hand-held and the shutter speed is set to a couple of seconds or more).  What's happening here is the camera is taking the picture even though there is not enough light (leading to the dark pictures).  You've told the camera (by selecting Tv mode) that I don't care that there's not enough light.  Just take the picture and close the shutter after x seconds has passed.  As the shutter remains open longer, you are letting more and more light in (accounting for the picture getting brighter) until you get to a point where you can no longer hold the camera perfectly still for the full duration that the shutter remains open (leading to the blurry image).

Lesson Five: The Sharpness Triad, Part I

In general, whether a picture turns out sharp or blurry will depend on three things.  If it does not turn out well, you can adjust one, two, or all three of these things to increase your chances of getting a better/ sharper picture.  The first thing to look into is the aperture.  As mentioned before, the aperature is the hole that lets light into the camera and since photography (literally 'light-writing'), at its most base level is dependent on light, the size of the aperature is an extremely important element in this equation.  The other two elements which we will discuss at a later time are shutter speed and ISO.  The bigger the aperature (remember, an aperture of f/4 is bigger than an aperture of f/8, see Lesson Two for a refresher), the more light gets in which means that the shutter has to remain open for a shorter amount of time to get a sharp picture.   

Lesson Two: That funny dial at the top

By this point, I'm sure you've gotten the chance to play with the camera a little bit and have probably noticed that funny dial at the top.  You know, the one with the funny pictures (such as the flower) and letter combinations (such as Av) on them.  I highly suggest you play around with each setting and get a feel for what each one does and when to use each one.  When you first start out, playing with just the settings that have symbols on them is just fine but eventually, you'll want to start experimenting with the semi-automatic settings of the camera, such as Av mode or Tv mode.  These settings are the reason you shelled out all that money for a digital SLR instead of a point and shoot camera.  The settings with the symbols on them will have the camera make all the setting adjustments for you.  Sure, you'll get decent enough pictures most of the time but to get excellent shots all the time, you'll want to start with either aperture priority (probably labeled Av mode, no, I don't know why it's labeled Av) or shutter priority (probably labeled Tv mode on Canons.  I believe some other companies may refer to it as Sv mode).  Most of the time Av mode will be your best choice.  In Av mode, what the camera does is have you set the aperture (Terminology Alert: opening in the camera that lets light through).  The camera will automatically adjust all other settings such as shutter speed based on the aperture setting you choose.  Often, you'll see aperture setting denoted as f/x where x=a number.  For instance f/3.5.  An aperture of f/3.5 is bigger than f/8 and so lets more light in.  A trick that I use to remember this is to pretend that the f =1.  So, just like in math, 1/3.5 is greater than 1/8.  This mode is great for all around shooting and especially for landscapes and other non-moving objects or slow-moving objects.  However, there are a couple of cons to using this mode.  Since the aperature is what takes priority in this setting, the camera may have to keep the shutter open longer which increases the chance of having a blurry image aka motion blur.  Also, as previously mentioned, this mode works well for non-moving or slow moving objects but if the object you're trying to photograph is moving fairly fast, you'll probably end up with motion blur. That's probably when you'll want to switch over to Tv or shutter priority mode which we'll cover next time.