Tuesday, 13 September 2011

Exercise 3: Focus At Different Apertures

Now I notice that the real challenge of distance learning is to allocate time each week to study. It is very easy to slip when your day job get busy. I am guilty for not following up with the blog (and my learning) for the past three weeks.

Now I need to catch up.

This exercise is about taking photographs on the same thing with different aperture. In normal portrait world, we tried to use large aperture to create boken. Such that the background is slightly blur and the focus is on our subject. This is normal practice except for environmental portrait. Since the effect in portrait is so well known, I would like to try something else in this exercise: Let’s try the same thing in landscape.

It is very difficult to find exactly what I have in mind, but I settled with an empty space with grass and with two trees at the end. It would be nicer if the houses are not there and the sky is bluer (ie. not so over-exposed). Colour-wise these set of images is not very good and I struggle to find the right colour I want. Any advice on this will be welcome.

Image 1 is what we will typical do in landscape, small aperture to get larger area of the photograph shape. Notice the grass at the bottom of the image.

 Image 1: 48mm f/18 ISO 800 at 1/60s



Now in image 2, the aperture size has been increased. Now we can see the grass in the front starts looking blur.

 
 Image 2: 46mm f/18 ISO 200 at 1/80s

In image 3, the bottom third of the image is very blur


 Image 3: 46mm f/2.8 ISO 200 at 1/250s

Personally I prefer image 1. I don’t really have a subject in this image so I prefer to keep the texture of the grass. Arguably, I can claim my subjects are the trees in image 3. However, if I am after the tree, I might change the composition to move my frame tighter all together.

It is possible to calculate the depth of field. There is a easy to read article written by Norman Koren here: http://www.normankoren.com/Tutorials/MTF6.html

In digital world, I find it easier to just take a shot and check from the LCD.

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