ISO, Shutter Speed and Aperture

Monday 30th September 2013

Over the past year especially, I have used the manual setting on my camera – and tried to avoid using the auto settings at all. I did have an understanding of ISO, Shutter speed and Aperture, however this task helped me understand it even more, to learn specifically about full stops, half stops… and to specifically see the difference of appearance in my photos.

My first attempt at these photos was in the lesson (car park behind Bradford College), but I felt as though I couldn’t photograph in the way I wanted so that I could show the proper affects of the changes in each area. I also forgot to change the ISO on a few attempts of different objects/scenes, which over/under exposed a few images which I wasn’t happy with. Here a few examples of the images I took on the day.

f/22 1/4 sec ISO 100

f/22 1/4 sec ISO 100f/4 1/250 sec ISO 100

f/4 1/250 sec ISO 100

As you can see here I tried to only stick with ‘full stops’ with the Aperture and Shutter speed, however neglected the ISO. The first image is over exposed and the second image is under exposed! I should have adjusted the shutter speed on the first image because as I result I have the slightest bit of blur, and it’s too bright, however in doing that I would have also had to adjust the aperture the same amount of stops/half stops to create a correct exposure. Despite everything that is wrong with these images, I do like how the 2 extremes in aperture show how at f/22 the whole images is sharp, however at f/4 there is a definite section that is sharp compared to the rest of the image that is out of focus.
Here is another example:

f/4 1/250 ISO 100

f/4 1/250 ISO 100

f/22 1/13 ISO 100

f/22 1/13 ISO 100

With this image, I wouldn’t say they are severely under/over exposed. There are slight differences in the lighting of each image, however they have turned out ok. The depth of field here is very prominent, which I like, especially on the first image. I like how higher apertures also, as well as letting in more light because of the largest opening in the lens, create more of a contrast between the colours in the image.
I think I definitely understand aperture, ISO and shutter speed however I think I have been careless and lazy with this task. I want to shoot it again and properly show my understanding of it. For now, this is my knowledge of the subject.

Aperture

The aperture is how big or small the opening in the camera is, which then determines the amount of light that is let in on to the sensor to create the image. If the aperture is highest (the smallest number e.g f/4) it means that the opening in the camera is the largest and is letting the most light in. This also affects the depth of field created. Higher apertures are usually better for things like macro or food photography, as you can get close to the subject and have a high depth of field, focusing on the main part you are wanting to show. If the aperture is the lowest (the highest number e.g f/22) the opening in the camera is the smallest, letting the least light in. The higher the aperture, the higher the depth of field – meaning the image will only be focused and sharp in the area you want and the rest will appear out of focus. The lower the aperture, the lower the depth of field – meaning all of the image will appear sharp. This lower aperture is good for landscape photography as all of the image, even e.g with different levels in the hills and landscape, is sharp.

Shutter Speed

The Shutter Speed is the speed at which the shutter closes and opens again, to capture the still image. The longer the shutter is open, the more light is let in and there is a lot of room for movement so the camera has to be kept very still. On the other hand the faster the shutter closes, less light travels through on to the sensor, therefore leaving you with a darker image. Using different shutter speeds can be advantageous for that of a sports photographer, as they would use a very fast shutter speed to capture the moving object, making it appear almost still. If doing so the photographer will also have to compensate for the lost light in the other areas – using a high aperture and ISO. Lower shutter speeds can be used in photographing movement or night scenes, light trails… letting in a lot of light where, if created using aperture/ISO, would either leave the image looking grainy/noisy (ISO) or would change the depth of field one wished to create.

ISO/ASA

The ISO/ASA is the third factor in how we control the amount of light that enters the camera. In film photography, it is the sensitivity of the film. In digital, it is the sensitivity of the sensor. The lower the light in the location you’re photographing, the higher ISO you would need. The higher the light, the lower the ISO. The result of these 2 opposites would result in a higher ISO producing an image with more grain/noise and a lower ISO producing a crisper image. It depends on the individual and what look you are going for, however the Aperture and Shutter Speed, again, need to compensate for the light lost/added to the image using the ISO. Some of the places ISO might become a priority would be inside buildings for example churches, art galleries etc. Also if wanting to capture an action shot in a poorly lit room/hall. ISO is also very handy if in a dark situation, you still want to portray the mood of the event/location but know that using flash to achieve that capture, wouldn’t work.

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