Week 4: Shutter Speed & ISO

30.8.13

Wan Mohd Danial (0316570),

Introduction2Photography

Exercise 2.2 & 2.3 : Shutter Speed & ISO

Lecture:

Shutter Speed

Shutter speed is the duration of time the shutter remains open to allow light to reach a digital camera. In other words, it is the duration of time, that the CCD is exposed to light. Measured in seconds, fractions of a second. Fast Shutter speed is used to freeze fast moving objects in picture while slow shutter speeds are used to show movement(blur) of an object. It is also recommended to use camera support when your shutter speed is 1/60 of a second (also depends on the speed of the object).

Here are some pictures we took as a small experiment:

Slow Shutter speed

Faster Shutter Speed

 ISO

The number indicating a digital camera sensors' sensitivity towards light. The higher the sensitivity, the less is needed to make an exposure. Shooting at a lower ISO number requires more light than shooting at a higher number. Lower numbers result in images with the least visible noise which is mostly desirable. The higher the ISO number, the more noise is on the picture.

Exercise:

Exercise 2.2

This exercise is to be done at home. We were told to take pictures of a ceiling fan to capture evidence of the shutter's ability to freeze  and blur fast moving objects. We need to keep the fan speed at 1 and capture images using the shutter settings from 1/4th of a second till 1/1000th of a second. Repeat this exercise after changing the fan speed from 1 to 2 and the from 2 to 3 and so on. Then record it in a table starting from the shutter speed 1/1000 of a second. 

The results:

Shutter Speed Table

Feedback 2.2

Mr. Vinod said that I had a good understanding of the Shutter Speed.

Reflections 2.2

From the table, we can see that the photograph taken with the highest shutter speed in the table is sharp & still. Proving that a higher shutter speed can freeze the subject matter which is the fan. While on lower shutter speeds, the photograph becomes blurry. Showing that lower shutter speeds are able to capture movements of a subject matter. On another note, it is also proven by the table that the faster the movement of the object, the higher the shutter speed required to freeze the object.

Exercise 2.3a 

For this exercise, we must produce evidence that ISO can directly affect exposure. we were required to shoot a subject using the lowest ISO setting to the highest. Determine the right exposure (shutter speed & aperture @ ISO 100) and then increase the ISO setting to 200, 400, and so on without adjusting the shutter speed and aperture again. Here are the pictures from this exercise:

ISO 200  F 4.5  SS 1/60

ISO 400  F 4.5  SS 1/60

ISO 800  F 4.5  SS 1/60

ISO 1600 F 4.5  SS 1/60

ISO 3200  F 4.5  SS 1/60

ISO 6400  F 4.5  SS 1/60

Feedback 2.3a

The first picture is a little dark eventhough it has the right exposure. However I managed to grasp the understanding of the ISO.

Reflections 2.3a

From these picture, It is shown that the higher the number of ISO used to take a picture, the higher the exposure of the picture. This is due to the camera becoming more sensitive to light and the amount of light that enters exceeds the amount that it needed for the right exposure making the picture overexposed.

Exercise 2.3b

Now, we must capture the evidence of degradation of image as the ISO increases in sensitivity. We still need to determine the right exposure (shutter speed & aperture) with the lowest ISO setting but this time we need to adjust our shutter speed & aperture to maintain the right exposure as we increase the ISO. Here are the pictures:

ISO 200  F 4.5 SS 1/60

ISO 400  F 4.5  SS 1/125

ISO 800  F 4.5  SS 1/250

ISO 1600  F 4.5  SS 1/500

ISO 3200  F 4.5  SS 1/1000

ISO 6400 F 4.5 SS 1/2000

Reflections 2.3b

The pictures comes out a bit dark but the exposure is correct. Degradation of the images can be clearly seen when picture is enlarge.

Reflections 2.3b

Look closely at the walls and you'll see that the amount of visible noise increases when the ISO number used to take the picture increases. Visible noise makes the picture look more pixelated and less clarity. The picture doesnt look good with all that white noise. Hence, it is proven that the increase of the ISO's sensitivity increases the degradation of the picture.

Screenshots:

General Feedback

After the tutorial, Mr Vinod reminded us about a few things. He said the instructions that he gives should be prioritised more than the instructions on the powerpoint. He also told us to not get hung up on the marks because what's important is the understanding and the learning outcome. Scientific parts are easier to get marks compared to the artistic parts of the Subject.