Camera构图之三分法

原文：http://photoinf.com/Golden_Mean/Eugene_Ilchenko/GoldenSection.html

http://digital-photography-school.com/rule-of-thirds/

Golden Section and Photography

Probably, you are here because you would like to know how to improve your photo technique,what is the Golden Mean, look at examples, read some articles or maybe use our on-linephoto-adjuster (I am still working on this, though). Yes, all the experienced photographers do know the "golden" rules of composition and use them almost innately. But before you start to use these simple rules without thinking, you need to practice, think what is better, and read about these rules. I am not going to describe the mathematical basics of these rules because they are well-described in other places, but here you'll find some examples, links to those descriptions, as well as JavaScript which could help you.

Rule of Thirds or Golden Ratio So, the first "golden" rule is the "Rule of Thirds" or "Golden Ratio".It affects the ratio (1:1.618) of a picture size, as well as the placement ofthe main subjects in the photo. This ratio is close to the 35mm ratio, so you don'tneed to change the size of the photo in most cases. But you need to consider the composition: main subject should lie on one of the four lines or four intersections (subject's eye for example). Truthfully speaking, these rules arenot always the same. Rule of Thirds is a simplified version of the Golden Mean. Golden Triangles Another rule is the "Golden Triangles". It's more convenient for photos with diagonal lines. There are three triangles with corresponding shapes. Just roughlyplace three subjects with approximate equal sizes in these triangles and this rule will be kept. Golden Spiral or Golden Rectangle And one more rule is a "Golden Spiral" or "Golden Rectangle" (you'll see why it's a rectangle in thetools section).There should be something, leading the eye to the center of the composition. It could be a line or several subjects. This "something" could just be there without leading the eyes, but it will fulfill its purpose anyway.

The Rule of Thirds is perhaps the most well known principle of photographic composition.

The “Rule of Thirds” one of the first things that budding digital photographers learn about in classes on photography and rightly so as it is the basis for well balanced and interesting shots.

I will say right up front however that rules are meant to be broken and ignoring this one doesn’t mean your images are necessarily unbalanced or uninteresting. However a wise person once told me that if you intend tobreak a rule you should always learn it first to make sure your breaking of it is all the more effective!

What is the Rule of Thirds?

The basic principle behind the rule of thirds is to imagine breaking an image down into thirds (both horizontally and vertically) so that you have 9 parts. As follows.

As you’re taking an image you would have done this in your mind through your viewfinder or in the LCD display that you use to frame your shot.

With this grid in mind the ‘rule of thirds’ now identifies four important parts of the image that you should consider placing points of interest in as you frame your image.

Not only this – but it also gives you four ‘lines’ that are also useful positions for elements in your photo.

The theory is that if you place points of interest in the intersections or along the lines that your photo becomes more balanced and will enable a viewer of the image to interact with it more naturally. Studies have shown that when viewing images that people’s eyes usually go to one of the intersection points most naturally rather than the center of the shot – using the rule of thirds works with this natural way of viewing an image rather than working against it.

In addition to the above picture of the bee where the bee’s eye becomes the point of focus here are some of examples:

Another Rule of Thirds Example

In this image I’ve purposely placed the head of my subject on one of the intersecting points – especially his eyes which are a natural point of focus for a portrait. His tie and flower also take up a secondary point of interest.

In this shot I’ve placed the subject along a whole line which means she is considerably off center and therefore creating an additional point of interest. Placing her right in the center of the frame could have resulted in an ‘awkward’ shot.

In a similar way a good technique for landscape shots is to position horizons along one of the horizontal lines also as I’ve done with the following shot (I’ll let you imagine the lines).

Using the Rule of Thirds comes naturally to some photographers but for many of us takes a little time and practice for it to become second nature.

In learning how to use the rule of thirds (and then to break it) the most important questions to be asking of yourself are:

• What are the points of interest in this shot?
• Where am I intentionally placing them?

Once again – remember that breaking the rule can result in some striking shots – so once you’ve learnt it experiment with purposely breaking it to see what you discover.

Lastly – keep the rule of thirds in mind as you edit your photos later on. Post production editing tools today have good tools for cropping and reframing images so that they fit within the rules. Experiment with some of your old shots to see what impact it might have on your photos.

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