Photography Composition Basics

Let me just briefly go through a photography tutorial explaining some terms and purpose of the technicalities of photography namely the ISO, shutter speed, aperture size and image sensors for digital cameras.

The ISO of the digital camera is the same as the ISO of a film based meaning how sensitive is the camera’s sensor to receive light and convert it into image where the higher the number the more sensitive it gets to light. The shutter speed is the speed where the cover that blocks the light from entering to the camera’s sensor will open and then close to let light in and the whole numbers are seconds, shutter is opened longer, while the fractions are fraction of a second, shutters closes fast. And last is the aperture size that is the amount of light the camera’s lens can allow to enter and reach the camera’s sensor where the measurements are in fraction of an inch.

I know what you are thinking, you are still puzzled. Just imagine you are taking a scene photo on a sunny day along the beach’s shore. You don’t need a flash to get this shot because of the natural brightness you get from the sun.So you will have to do a proper mixture of the ISO, shutter speed, and aperture size. Since it is very bright, you need to get your ISO to 200 or lower, if available because those are not so sensitive to light. Then you have to adjust the shutter speed to a fast one to avoid over exposure because the shutter stayed open for a long time. Then comes the aperture, this one is a bit tricky, keeping it too small means there is lesser light to reach the sensor so you will have to slow the speed of the shutter a bit to avoid under exposure and the outcome of this is a full detailed image from foreground to background. However, if you set the aperture size to the maximum size it has then you will have to increase the speed of the shutter a bit to avoid over exposure and the outcome of this is that the image’s main subject will be clear while the other parts of the image is blurred. If you still did not get it, I don’t know how to make it simpler, sorry.

Let us define ISO deeper. You might have seen images with grains or pixels in the image with various brightness or color information evident on dark areas or objects whose colours are close to black such as hairs! Yes, the ISO affects this where the more sensitive it gets the higher the tendencies to get more noise in your image.

So, you might be wondering how are you going to shoot in dark areas or images with black on it? It is simple, you just have to lower the resolution! I have tried with a Sony DSC-W220 model whose highest resolution is 12mp by capturing the night sky to visibly see the stars of the constellation Orion (tip: the stars are brighter in rural areas for there are fewer artificial lights). I had the camera’s settings at ISO 3200 and resolution at 5mp where it gave a fairly good image with almost no image noise. For a DSLR at 12mp, you might just need to bring it to 8mp or even not at all.

You might be wondering again why DSLRs need not to lower the resolution when capturing dark areas? The factors that yeilds this are the camera’s sensor’s sensitivity, the ISO level, and the sensor’s size plays a factor. Many small digital cameras today offer higher resolutions at cheaper prices because they have a small sensor size no bigger than the nail of your pinky finger, mind you, a bigger sensor means it is more expensive that explains a DSLR’s price. Simply put, the sensor of a small digital camera needs to work hard to produce a 12mp picture compared to DSLR’s sensor at 12mp whose sensor size might be half the size of a regular 35mm film or even bigger!

Image processors nowadays also play a vital role in reducing image noise. Some small cameras who are comparable to say Sony’s DSC-W220 might not be able to produce the same clear image at ISO 800 with 12mp resolution due to the processor’s low noise reducing capability. However, they might offer other features to compensate this such as LCDs at the front or Photoshop like editing features.

That is the end, if you have suggestions or corrections, please mail them to me.

 -Xycris