|Posted by caseycrockerphoto on June 28, 2010 at 5:45 PM|
Three Little Lessons : Crash Photo
The lower the ISO setting the more color and overall tonality your image will have. 100 iso has twice the colors as 200 iso. 200 has twice that of 400 and so on. Think of like crayons. Do you want to use the 128 pack or do you.want the 8 pack? Keep this in mind too...the ISO and the shutter speed are closely related, like a marriage. When the ISO is higher like 800 and 1600 the faster the shutter speed can be. You reduce color but you increase shutter speed. So when you can't sacrifice the shutter due to motion blur, either by your own hand or due to the subject, you'll have to sacrifice a bit of color fidelity. Sometimes a fair balance can be made. Just like a marriage.
The shutter speed records time. The illusion of time in an image is due to the quickness or slowness of the shutter door. This door is iinside the camera and is next to the film or digital sensor. The human hand can generally only hold the camera steady for as long as the lenses length and retain a sharp image. Any time longer can result in a blur due to the photographers movement. For instance if you use a 200mm lens then the longest shutter speed you can hand hold without camera shake is a 200th of a second. There are image stabilizing lenses and cameras that can help with this.It is also common for a photographer to set a shutter speed and choose a ISO film speed that ensures a proper exposure. Even if a sacrifice in color occurs. With digital photo a slight underexposure (dark picture) is acceptabe because the photo can be brightened later. However too much underexposure and brightening can create graininess in a print that won't really be noticed on the screen.
The aperture of the camera allows you to not only change how much light is let into the camera but primarily allows you to change how much of the scene is allowed to be on focus. Now you may notice that the camera will give you aperture settings that are f/4, f/5.6, f/8, f/11, f/16, & f/22. The lower the number the more light is allowed through the camera AND the shallower the depth of field of the scene (small amount of area in focus). This is a choice that needs to be made. The aperture controls space while the shutter controls time. A photograph is generally about one of these two things so when shooting consider whether the scene is more about time or more about space. If you'll notice there is a pattern in the numbers above. F/16 has twice the amount of depth of field than f/8, which in turn has twice the depth of field than f/4 and so on. So if we were to shoot a landscape with a waterfall in it the settings would be close to 100 ISO at f/22 with a shutter speed around 1 second. This maximizes color, gives a great (deep) depth of field, and creates a flow in the water. If we were shooting a musician or athlete the settings would be quite opposite: ISO 1600 at f4 (ish) at around 1/500th of a second. This would sacrifice color and depth of field but cause a quickening of the shutter speed enough to stop the blur of the person playing their instrument or sport.