​The application of focal length in landscape photography

The application of focal length in landscape photography

Hyper focal distance focusing is a kind of relatively high-end focus method, a lot of friends don't know what on earth the so-called hyper focal distance focus is, and more do not understand the principle and method of use. Some netizens although slightly on the unknown, but it is difficult to the clear written in paper to share with you. The following about hyper focal distance focus depth resolution involving the hyper focal distance focus principle and use method, believe that interested in the technology of friends will understand after reading a lot.

prints for the wall

I still remember when af phase is a new technology, many photographers are suspicious of it. But is contrary to the autofocus technology development is increasingly perfect, can be seen everywhere, manual focus lens now are becoming more rare. Sometimes it's easy to forget it is best to autofocus closed, to rely on manual focus. When you use a wide Angle lens canvas prints scenery photo is a good example. In this case, you may want to put the whole scene was as sharp as possible. But if the scene's closest to you things that only a few centimeters away from the camera, how do you do it? The answer is that you need to understand the depth of field, and is willing to manually control the camera focus system, accurately determine where you really want to focus, rather than work to continue to focus the camera.

What is the depth of field? Keep clear before and after the depth of field is the focus area. The depth of field to a certain extent depends on the size of the camera Settings (lens focal length and aperture, and partially depends on the size of the other such as in the photo and the audience's eyes and other factors. Clarity is subjective - clear object for a person, may not be clear for another person. We will continue in the article, please remember that.

Imagine that you are in an APS - C camera used on a 24 mm lens (or set the focal length is 24 mm zoom lens), to a point in a meters in front of a camera lens. You set the aperture of the lens to f / 11, because you want to shoot a clear canvas prints photos (usually the aperture of the lens sharpest set to f / 8 / f / 11). In this case, some 73 cm to 157 cm range from you everything is clear. It is your focus away from the camera is too close to what will happen. You focus on the area around is very clear, but close to the object on the distant horizon is become very vague. It is the case in the actual situation, a meters away from the camera (lens to focus) of all the objects are clear, and the meters on both sides of the object fuzzy gradually, until the human eye can no longer think these objects are still in the focal point.

Where do I get the above these Numbers? I use DOF calculator to get the data. The data in the DOF depth of field is a calculator in my choice of EOS 7 d computed camera, camera choice is very important, because of the depth of field by photosensitive component size, and the influence of the lens focal length and aperture Settings. We have just seen, at infinity focus effectively waste a lot of depth of field. And if you are using hyper focal distance will get better results. What is the focal length?

The depth of field calculator will give you another number -- hyper focal distance. It means you are using a lens focal length and aperture, focus can still keep from objects in focus to infinity area clear a bit recently. I have just set, for example, at this time of the focal length of 2.7 meters. If focusing on this point, then 1.34 meters away from the camera to infinity are clearly within the scope of the object area. This can help you maximize depth range, and can help you try to make the whole scene is clear.

Than the focal length of the actual application: using hyper focal distance the easiest way is to print or copy a series hyper focal distance form, when shooting and carry (DOF Master website have you print out these forms to bring). In addition, the following Smartphone applications can also help you to calculate this series of data (if you search DOF or hyper focal distance, you will find that there are many other programs). Once you get the information you need, you'll need a focus on the lens barrel range indicator to tell you the window lens distance range. Many cameras have distance instruction window, but some random set of head and the biscuit lenses without the instructions window). From the data in the window is not accurate, so you have to do some ready for measurements.

If your camera is not the distance scale, then your only option speculation distance (or use a tape measure). It is not difficult but fortunately speculation distance. When you have finished filming the canvas prints pictures, you can enlarge photos on the camera's LCD screen, confirm again photos of depth of field, to check its definition. However, such doing is effective depends on your camera's LCD screen resolution and size, but you should be able to judge your nearest your scene is clear. Only when you go home later check the photos on the computer monitor can determine whether or not clear, but by checking the LCD screen, you can still find that your calculation is there some serious mistakes.

Given using hyper focal distance when there are many variables and is very likely to be some mistakes, there is a safe way of using hyper focal distance, that is to continue to use, according to a certain aperture setting (e.g., f / 8) calculated values, but the actual filming will set the aperture of the camera a (such as adjusting to f / 11), it will leave you some space to make mistakes.