ISO, Shutter Speed, Aperture: Part III

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Aperture is the last of the three major elements in photography (and has always been the trickiest one for me to wrap my head around). It’s the hole through which light travels and enters the camera, and adjusting the setting affects how big or small that hole is.

Aperture affects a photo’s depth of field — how much of the photo will be in focus:

  • A small (or shallow) depth of field means less of the photo will be in focus and is created with a larger aperture (a bigger hole).
  • A large depth of field means a larger portion of the photo is in focus relative and is created with a smaller aperture (a smaller hole).

For example, in this picture where the baseball pitcher is more focused and clearer compared to the crowd, a pretty large aperture was probably used. On the other hand, this one, where the pitcher and the crowd are both in focus, was likely taken with a smaller aperture.

Aperture is measured in “f-stops.” The range of my G12 point-and-shoot is from f/2.8 to f/8.0; high-quality DSLRs can have ranges from f/1.2 to f/22. Because these are fractions, a large aperture means the bottom number is actually smaller, and a small aperture means the bottom number is bigger.

So,

  • Large depth of field = small aperture = large denominator in f-stops.
  • Small depth-of-field = large aperture = small denominator in f-stops.

Just like ISO and shutter speed, adjusting aperture has trade-offs:

  • A smaller aperture (e.g., f/8.0) means you’re letting less light in, so you may have to increase ISO or slow down shutter speed to get a properly lighted, shallow depth of field.
  • Conversely, a larger aperture (e.g., f/2.8) means you’re letting a lot of light in, so you’d want to decrease ISO or use a faster shutter speed to make sure the photo isn’t overexposed.

I had some trouble capturing images that really illustrated the concept clearly, maybe due to the limitations of my little G12 point-and-shoot, user error, or some combination of the two. A few of my attempts are below, but this post is also a helpful guide.

For this picture, I used a relatively small aperture and slow shutter speed:

Aperture: f/8.0 ISO: 1000 Shutter Speed: 1/15

Aperture: f/8.0
ISO: 1000
Shutter Speed: 1/15

In this one, I used a larger aperture and faster shutter speed, and the exercise machines in the background are blurrier compared to the first picture:

Aperture: f/2.8 ISO: 1000 Shutter Speed: 1/100

Aperture: f/2.8
ISO: 1000
Shutter Speed: 1/100

Fun fact about proportions: Going from one f-stop to the next doubles or halves the aperture. So if you know you are decreasing the aperture by half, you could make the shutter speed twice as slow as the original speed to reverse the effect on the amount of light being let in.

The end!

ISO, Shutter Speed, Aperture: Part II

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The second major element that affects how a photo will turn out is shutter speed: the amount of time the shutter is open when taking a picture. (The first element, which I discussed in an earlier post, is ISO.) Shutter speed is measured in seconds and fractions of seconds. For example, the range of my G12 point-and-shoot goes from 15 seconds to 1/2000 of a second; higher quality DSLRs can have shutter speeds as fast as 1/8000 of a second.

Shutter speed controls the ability to freeze motion when taking pictures. A shutter speed of 1/60 would probably be fine to capture someone walking, but you’d need a shutter speed closer to 1/250 to capture a runner clearly. It’s especially important in sports photography, and a shutter speed around 1/1000 is necessary to capture something like a pitcher throwing a baseball.

(Side Note: Some cameras only show the denominator rather than a fraction for shutter speed, in which case the bigger numbers would actually mean a faster shutter speed.)

Similar to ISO, there is a tradeoff:

  • A faster shutter speed allows you to capture motion better, but lets less light in.
  • A slower shutter speed makes motion blurry, but creates a brighter image.

Here are three pictures from the ice skating rink at Bryant Park, taken with varying shutter speeds.

In the first one, the shutter speed is too slow to capture the motion of the skaters, making them blurry:

Shutter Speed: 1/10 ISO: 1600 Aperture: f/4.0

Shutter Speed: 1/10
ISO: 1600
Aperture: f/4.0

A faster shutter speed freezes the action better, but creates a darker image because less light is being let in…

Shutter Speed: 1/100 ISO: 1600 Aperture: f/4.0

Shutter Speed: 1/100
ISO: 1600
Aperture: f/4.0

…so you can increase the ISO to make the sensor more light sensitive, and the resulting photo is brighter, and the skaters’ motion is still captured clearly:

Shutter Speed: 1/100 ISO: 3200 Aperture: f/4.0

Shutter Speed: 1/100
ISO: 3200
Aperture: f/4.0

The driving factor behind all three of the elements is how they affect the amount of light that is let in. ISO affects sensitivity to light and how “absorbent” the image sensor is, while shutter speed affects how much light can get in before the shutter closes down.

Next up: aperture!

ISO, Shutter Speed, Aperture: Part 1

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Photojournalism was the class in jschool that I kept meaning to take, but that somehow always got shafted due to time conflicts with requirements and other more pressing electives. I did manage to get in a couple of weekend workshops and a 4-week news photography “module,” and I really enjoyed working on the assignments for them.

Even though my Canon G12 point-and-shoot isn’t that much better technically than my iPhone camera, I like that I can take pictures in the manual mode with the G12. Shooting in manual allows you to play around with the three main elements that affect how a picture turns out: 1) ISO; 2) shutter speed; and 3) aperture.

I thought it’d be fun to go out and take some pictures and put together a very basic explanation of how those three elements work because I think it’s really interesting how they are all interconnected. Here’s ISO; shutter speed and aperture will follow!

ISO, which stands for International Organization of Standardization, affects the sensitivity of the camera’s image sensor and how much light is absorbed. It’s sort of like telling a sponge to be more or less absorbant:

  • A higher ISO means the image sensor is more sensitive to light, and the picture will be brighter.
  • A lower ISO means the image sensor is less light is sensitive to light, and the picture will be darker.

There is a tradeoff in picture quality, however, and higher ISOs create grainier images. So the more natural light there is, the lower you can make the ISO, and the better the picture quality will likely be.

Here are photos of the holiday light show in Grand Central with three different ISOs. The other two elements (shutter speed and aperture) were kept constant:

ISO 250

ISO: 250
Shutter Speed: 1/10
Aperture: f/4.0

ISO: 800 Shutter Speed: 1/10 Aperture: f/4.0

ISO: 800
Shutter Speed: 1/10
Aperture: f/4.0

ISO: 2500 Shutter Speed: 1/10 Aperture: f/4.0

ISO: 2500
Shutter Speed: 1/10
Aperture: f/4.0

The G12’s ISO range is from 80 to 3200; high-end DSLRs have ISOs that go up to 25,600. You can play around with different camera settings to see how they’ll affect an image with this online photo simulator.

Stay tuned for shutter speed!

Soccer musings: MLS growth, popularity and salaries

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Major League Soccer (MLS) was founded in 1993 because FIFA made it a requirement for the U.S. to be able to host the 1994 World Cup. It struggled to gain traction at the onset but has continued to increase in popularity. According to Forbes, average attendance has increased 35 percent from 2000 (13,700 fans) to 2013 (18,600 fans), and an ESPN poll showed that the percentage of people who considered themselves “avid fans” increased 43 percent from 2002 to 2012.

From the Forbes piece:

MLS’ avid fan base is the fastest growing of any sport, outpacing all others in the ten-year periods from 2001 to 2011 as well as 2002 to 2012. And the gains come from nearly all ages of both genders.

I’m not sure if it’s impressive that a professional sports league that started out as a simple obligatory response to FIFA has grown so quickly, or if it’s incredible that it took this long for U.S. sports fans to get on board with arguably the world’s most popular sport.

[A somewhat tangential fun fact: The median base salary for MLS players as of May 2013 was $75,000 and the average was $141,900. For comparison, the median salary in the MLB in 2013 was $1.1 million and the average was $3.4 million. (I’m including the median because in both leagues there is significant income disparity between a handful of players at the top and the rest of the league, which makes the average a little misleading.) In fact, a lot of professional-caliber players in the U.S. elect to play in semi-pro leagues while they work full-time jobs in finance or other more lucrative industries.]

Clark Hunt, chairman and CEO of the Kansas City Chiefs and founding investor-owner in MLS, told Forbes he thought that soccer could be the No. 2 sport in the U.S. in his lifetime. (Hunt is 48.) I don’t know that I’d go that far yet, but between the facts and figures and anecdotes from various people, it does seem like the MLS could be on the verge of a pretty considerable growth spurt. It got me thinking about the start of other professional leagues in the U.S., and I believe the NBA also struggled to gain popularity, particularly with TV audiences, early on. I’m not as familiar with the history of the NHL, but I’d be curious if there are analogies with MLS since they’re both sports that were popular elsewhere first, before expanding to the U.S. Maybe a topic for another time…