Lesson #2: Aperture

Aperture is the opening in the lens that allows light to pass through and hit the sensor. The smaller the number, the bigger the aperture and the more light can pass through. For example, f/2.8 is a larger aperture than f/5.6. Your little kit lens has a variable aperture. What that means is that at the wide angle end the maximum (largest) aperture is probably something like f/3.5 and at the telephoto end it is probably f/5.6. Photo-snobs1 will sneer at you while you’re making photographs with a variable aperture lens. But that’s exactly what they’re doing -- sneering -- and you’re making photos.

The trick with aperture is that it affects your depth of field. Depth of field is the distance in-front-of and behind the subject that is in focus. A large aperture (big opening, small number, like f/2.8) means there will be little depth of field. A small aperture (little opening, big number, like f/22) means there will be lots of depth of field.

For your second assignment, find a stationary object that has something moving on it and there have to be stationary things in the background. And it should probably be pretty sunny out for this to work like it should.

When I learned this lesson, it was with a fountain spurting water and that’s what I recommend. If you can’t find a fountain. Whatever the object is doesn’t matter. It just has to be still, but there has to be something on it that’s moving.

Take your kit lens and put it out to its longest telephoto setting, 55mm or whatever. Then set your camera to its “A” or “Av” mode and the ISO to 100, and make photos of your subject at f/5.6, f/8, f/11, f/16 and f/22.

Now go and put your photos on your computer. Looking at your photos, see how as the aperture gets smaller whatever is behind your subject gets clearer and clearer? That’s depth of field, and it also applies to anything in-front of your subject.

Now here’s the really tricky part. Take a close look at whatever was moving on your subject. Do you see what happens to that as your aperture gets smaller? If you found a fountain to shoot, the water droplets at large apertures are fairly well frozen in space (if it was bright enough outside). But at smaller apertures, the water droplets are blurry and blended together ... which takes us into lesson #3. Oh, and ENJOY YOUR photos!!

Footnote1
 A photo-snob is a person who is more interested in the camera you’re shooting than the photographs you are creating. Photo-snobs will sneer if you don’t have the priciest of gear. Photo-snobs spend a lot of time arguing about cameras and lenses on the internet, and will often have a long string of gear they own attached to each of their posts on those message boards. But, and this is the key tell-tale, they have very few (or none at all) photographs of their own on display for others to see.

Next lesson!