By adjusting settings properly, photographers can avoid coming back with blurry, unreadable images.
I hope you sailors are saving these photography articles. Taken issue by issue, you will learn all the basics and more. Last time I began discussing the relationship between the aperture and shutter. Why and how we use both to control light and be creative.
It may have been confusing when I mentioned aperture openings or f-stops such as f/2 and f/22. Few pocket cameras reach those outer limits, and more often have a range from f/2.8 to f/8. Here are a couple of brief notations to add to the discussion in the previous May issue: a] you can control aperture with the creative zone/mode dial in Av (aperture priority) or M (manual) setting, b] f/stops can range larger – f/2, f1.8, and smaller f/32, f/64, and can be given in increments such as ½ stops, and c] there are other nuances talking about apertures-F/stops we can look at later on. But for now we will stay with basic- essentials; the Aperture (f/stop) controls light with each full stop opening up from f/8 to f/5.6 to f/4 to f/2.8 doubling (2X) the amount of light coming into the camera to expose the photograph. The reverse, of course, closes down and reduces the light by ½. And the higher the number (f/8 being higher than f/5.6), the smaller the aperture (opening) the more things, close to distant, remain in focus.
The second part of the equation in controlling the right amount of light to take a perfect picture is the shutter. Shown below is a photograph, taken with my pocket camera after sunset, of a friend speeding down the Inter-coastal in his boat. He wanted a nice shot to send to his family up North. Do you think they’ll like it? The camera settings were f/8 and 1/15 (of a second). Keep these aperture and shutter speed settings in mind.
What is the shutter? In larger photographic formats they can exist in lenses, but most often they are in the camera body in front of the capture media, that is the chip (formerly film). Think of the shutter as a window with curtains. The shutters speeds determine how long these curtains remain open to help expose the perfect photograph.
Most pocket camera shutter speed settings show B, then 15, 8, 4, 2, 1 second, onward to ½, ¼, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500. 1/1000, 1/2000 of a second, and, like with my camera, many incremental settings in between when I’m in the Tv (shutter priority) or M (manual) creative zone/mode. Those I have listed are the main full stop settings. Meaning 1/1000 of a second allows in 2X the amount of light to reach the chip as does 1/2000. This goes all the way along, so 15 seconds, being approximately 2X longer than 8 seconds allows 2X the light to reach the chip. [“B” for bulb means as long as you press the shutter release (picture taking) button the curtains stay open. I mention this in parenthesis to talk about this another time.]
Why have shutter speeds? We can control the amount of light reaching the capture chip simply with the aperture. But the aperture can only control depth of field or what stays in focus from near to far (distance). The shutter on the other hand can control motion; the faster the shutter (with 1/125 being faster than 1/60 being faster than 1/30 of a second) the better able it is to stop, that is freeze movement.
Let’s get back to my friend’s boat photograph above. It shows movement, which is exciting, but doesn’t provide a very good depiction for showing the boat to his family. That was my only chance, the only time of day I could get this photograph, so where did I go wrong with it looking like a blur? I do have a solution to making it right, but it will have to wait for space in the next issue. I know, what a plank hanger to leave you on, but until next time…… permission to come ashore. Send me your questions to possibly cover in next issue.