What does f-stop (aperture) mean?
The aperture and how it works can be confusing to some of you.
The aperture is the part of a lens that determines how much light is
let through to the sensor. If it’s wide open, lots of light gets through. If it’s closed
down, only a little light gets through. Aperture settings are expressed as decimal numbers, and work opposite to the way you’d think... a higher number will let in less light than a lower number. Each aperture has an Open, and a
Closed – the most and least light it will let in. In between it is what is known as the
f-stops, or aperture settings – numbers like f1.6, f2.8, f6.0, f16.0, with many in between. And not all lenses will have the same apertures....for example.. a cheaper lens may only open to
f3.5 or a f4.0, not letting in as much light as a more expensive lens that will open all the way to an f1.6.
When you change the f-stop, it will affect your "depth of field"
In these two pictures you can see the difference. the lower f -stop (I had it at 2.8) causes the background to really be blurred.
and with the higher f-stop (this one was set at 8.0) the background isn't so blurred.
What is shutter speed?
The shutter is what determines the length of time the sensor is exposed to light.
Shutter speed is usually expressed as a fraction – 1/2, 1/30, 1/80, 1/125,
etc. Some professional cameras go as high as 1/2000, or even higher.
The longer the shutter is open, the more light is hitting the sensor. A shutter speed of 1/4 means that the shutter is open for one quarter of a second, while a shutter speed of 1/2000
means it is open for only one two thousandth of a second.
A slow shutter speed picks up camera motion, and is one of the primary causes of blurry pictures. A safe rule for most situations is that you want a shutter speed of at least 1/50 or 1/60, but the faster, the better. If you go much lower than that, you will need a tripod, or you will have a blurry picture. But keep in mind, that if you are using a tripod, it will still blur a moving object. This picture was taken with a tripod with the shutter open for 2 seconds. Notice that the lights in the water are blurry because the water was 'moving'.
While practicing with shutter speed, Anita got this great picture....and with a tripod she could have gotten the greener and rocks around it to be a lot sharper. Anita, do you remember what your shutter speed was for this?
And one more picture....just shows a difference between automatic and manual.... This was taken in open shade, and they are straight out of the camera. The one on the left was taken in automatic, and the right is manual. Much nicer picture in manual!
Maybe next week I will touch a little bit on ISO, but for now, practice with these two things. And let me know how you do :)
I'm trying to shoot moving water at somewhere around 1/12 or 1/15 with an iso of probably 200. At least I think so! I have to cram these little bits in my head a wee bit at a time ... or they don't stick. I just try to remember that 1/60 is what the human eye sees, at least with water.
ReplyDeleteYou wouldn't believe what I drove trying to get state fair lights from above .. and never managed it. Will keep trying to find something with light to play with. I absolutely love that picture of Tempe Town Lake! Will blog later this evening or in the morning .. I'm going to have a few more hours in the week to play with the camera! Can't wait!!
great tips! On the last pictures, what was the difference? Lower shutter speed on the right?
ReplyDeleteKeilah,
ReplyDeleteFor the picture on the right, my settings were: f-stop was 2.8, shutter speed was 1/800, and my ISO was 500
shot with my 24-70 lens at 68mm
for the one on the left, in automatic settings, the camera took it at: 1/320 shutter speed, f-stop was 5.6 and ISO was 400