ISO – how much available light I need to pull into the cameras image sensor. If I have too much light, full sun with a high number on the ISO I can literally get a white image. Same on the flip side in a dark room, with a low number, the image will be black. I need to tell the camera how much ‘light’ to allow in for a balanced image. Some of you may remember film, you know the transparent plastic roll that we put in our cameras, take 12 -24 photos, and then drop off to a facility to have printed – fingers crossed. Back in the day typical film was 100 ISO, taking its best photos in daylight; 800 ISO was used for lower light and was grainy. Today’s cameras can take a fairly nice photo at 6400 ISO; eyes will not be as crystal clear, but still stunning images.
Aperture - measured in ‘f-stops’ is how much lens we open. The lower the number the more shallow the depth of field (only a small portion of the photo is crystal clear). When you see those amazing photos where the bride is showing off her ring or bouquet and those items are crystal clear where anything in front or behind is blurry, that is probably a lower say f/2.8 aperture. It is typically done with settings in the camera at the time the photo is taken. A full view of a sweeping vista would be a f/16 or larger aperture so everything is sharp and in focus, fair away mountains and up close shrubbery.
Shutter Speed – Shutter speed is measured in fractions of a second. Couple different things I need to think about is, is my subject moving and/or am I moving. Without a tripod, I will shake just a hair holding and pressing the shutter button. I need to compensate for being human. If my subject is standing for a portrait, I can probably be safely at 1/60, if I’m filming moving musicians, 1/200 is safer although with low light sometimes I’m trying to snag a paused moment at 1/100. Capturing little tykes running around at least 1/250 and fast moving vehicles especially race cars 1/1200. – This is where we might get artistic. Do we want a full stop on the musician strumming, the stream flowing or the car moving or do we want to show a bit of a blur? The musicians head is in focus, his hand is blurring with the movement. The mountains are in focus, the stream has a blurred flow, etc. We would adjust, lowering the speed to gain some artistic flare in our photo.
There is no formula, every scenario is different. Daylight I might take photos of a family at 100 ISO with an f/8 aperture and have a 1/250 shutter speed available, that same scenario with good inside light would need possibly 1200 ISO, line them up with a f/5.6 aperture and I’d possibly have 1/100 shutter speed. In a home with no special lighting you won’t be able to have a large aperture or fast shutter speed. Your ‘model’s will need to be slower or standing still for the best photos. That is why lighting it so essential at wedding receptions with dancing and often brought in for the event.
I have opportunity to photograph concerts since my husband is an amazing guitar player. Some venues not only have constantly changing lights, but lights in a variety of colors. You can snap two consecutive photos, one in the white light and the other with a red or purple spot and the first photo will be lighter and clearer in the bright light. Those fun funky colors play havoc with the camera. And often you’ll notice photographer might change concerts, or party scenes with crazy lighting into black and white to pull out this ‘distortion’.
So I am constantly changing these settings. The more light we have the sharper the image will be. However excessive light and shadows are a challenge as well. Constant variables which can be fun and frustrating in the same moment!
Little snippet so you might start to get an idea of what we are doing when we hesitate looking through the lens until we snap the shutter. We’re working our triangle to create a lovely image!