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The auto-focus SLR cameras now easily meets the requirements of the average user. In addition to things like pre-programmed exposure modes, the auto focus function of an acceptable result for most will be delivered. However, the use of this feature can be a bit 'to be desired when a job requires critical control over every aspect of the photographic recording process.

Older film cameras, especially for commercial use even on things likeAccurate focusing and barrels lens hyperfocal distance information, split-screen or similar supports hunters and accessible aperture stop-down levers or push buttons engraved. Today many of DSLRs come with zoom lenses and lens focal length and zoom lenses have depth of field (DOF) hyperfocal distance markings or pointers so if you want to focus maximum control, you are in your possession. This article explains the concept of DOF guide and how toconsistently applied, to take photos. There are also two places after that to test do-it-yourself deep with the camera and lens and focus on the concept of hyperfocal distance.

Understand what AF is crucial to know when to turn it off and go full manual. Believe me, you can not critically evaluate DOF look through the viewfinder or watch the recorded image on the preview screen, no matter how you enlarge. Physicsare simply not in your favor. You can, however, a number of simple principles and data tables for creating your focus is bang-on every time without pulling hair. In the rest of this article, I am going to industrial-strength tools for understanding the process and to monitor the results of the morning. Additional information about diving

For each point (actually a plane) Focused on a goal, there is a space in front and behind the point where acceptable, will be sharp This is known asthe "DOF". For example, if we are critical to an object that is 18 meters from the camera and the DOF generally 9 feet, objects 15-24 meters will be in focus focus acceptable. DOF is a key fixed optics, and applies to all lenses at all times regardless of the design target or what the seller says to save the camera for you.

Moreover, the general rule is that the depth of field is divided into thirds. For each point focused on a third of the DOF before the critical point will be focaland two thirds will be back. That is why, in the example above, we know that the room is at the heart of 15-24 meters, one third of the depth of field is Focused on the front and two thirds behind the object. So, for the implementation of this concept, if you show a picture and the camera focuses on his nose, 1/3rd depth of field in front of the plane of the nose and 2/3rd behind. Assuming that the global DOF should be shot in the head in the aisle from front to back. Moston this a bit '.

Therefore, we must understand that determined by DOF lens focal length, f-stop and the camera to subject distance. We can use depth of field for any combination of these three factors, or more convenient, we can consult our tables to calculate the lentils. Please watch at least the tables on http://www.dofmaster.com DOF presented.

By visiting this site, you can give your contribution to the camera, the lens focal length and the rapid production of a finished table.Obviously, to zoom lenses, the entrance to each of the first settings as indicated on the lens barrel 17, 35, 50, 85, 100 mm and print a table for everyone. I printed a set for my lenses and keep a copy in my camera bag with a 25 'tape measure. The tables and meters are the bread and butter of control fire!

Review these tables you will find the following general optical understand:

First short focal length to give more depth of field slower.
The second increase of the camera to subject distance increases the depth of field.
Third closing the aperture gives greater depth of field.
Fourth 1/3rd the depth of field is focused on the object in front 2/3rds is back.

prepared as an example, a table of advice for my Canon 30D and a 50mm lens, we determined that when an object is concentrated in 10 "on our DOF is f 2.8 from 9'-5" 10'-8 " but if we attack F-16, we focus to 7'-4 "15'-9". Even a difference!

With understanding andconcentrated application of the tables, take full control of the process of focusing the extent that you know the DOF and where they fall. This gives security to view real time how the images are not finished suspect, look and allows you to manipulate the process to help focus your creative purposes.

The next article in this series is called "Depth of Field DSLR Testing" and describe how to perform a simple series of tests with the camera to show just how deep it actually does.Finally, there is a condition for further hyperfocal distance, I have a lot in the third known type: DSLR and hyperfocal distance. "

Finally, thanks to Don Fleming on the installation and maintenance http://www.dofmaster.com a wonderful site that all possible information and free goodies in connection with DOF and related entities, has.

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