light situations

Photo Assignment #2: Relationship Between ISO & Shutter Speed

Our second assignment is all about ISO and its relationship with shutter speed.

From my understanding, ISO is the digital equivalent to film speed. By increasing the ISO, you are better able to shoot in lower light situations. But also, as you increase the ISO, you begin to see more noise or graininess in the images. Though it may produce poorer quality prints, I think that there are some who like the effect. It also gives your images a bit more of a film feel. Now, being a newbie to all of this, what I’ve just written may not make any sense at all… but I’ll learn.

The assignment…

  1. Set the camera to program mode (this allows you to have control over the ISO, while the camera automatically adjusts the shutter speed
  2. Set the camera to its lowest ISO (for me, that’s 200)
  3. Take a pic and note the shutter speed
  4. Double the ISO, take a pic and note the shutter speed… And repeat

ISO 200…


f/9, 1/1250 (at 31mm)

ISO 400…


f/10, 1/1600 (at 31mm)

ISO 800…


f/13, 1/2500 (at 31mm)

ISO 1600…


f/14, 1/3200 (at 31mm)

ISO 3200…


f/18, 1/4000 (at 31mm)

ISO 6400…


f/25, 1/4000 (at 31mm)

ISO 12800…


f/25, 1/4000 (31mm)

I know, it’s a bench. Not a very exciting photo set. Stick with me though, the photos will get better eventually.

Final thoughts…

As you can see, for each increase in ISO, the camera compensated by increasing the shutter speed, and reducing the aperture. Again, a higher ISO lets more light hit the sensor, so the camera balanced that by quickening the shutter and reducing the size of the aperture.

Wow, I just learned a little more about the relationship between the three elements – ISO, shutter, and aperture.

Now, because my camera is not a pro grade camera, my max shutter speed is 1/4000. At this point, the photos began to look blown out (or over exposed) and gradually lost detail. On reflection, I guess this exercise was also a good way to help me understand the limitations of my equipment.

Ok, I’m off to tackle assignment #3… depth of field. I love the look of photos with blurry backgrounds so I’m really excited about this one.