​4 things you need to know about focusing

Learn photography for a period of time, canvas prints can understand the general monocular camera will have several kinds of auto focus mode, roughly grasp what kind of situation to switch to use, and may also know how to manually choose the focus to achieve more accurate focus effect. Beyond the basics of this type of operation, what else do you need to know about focusing? Take a look at these 4 small knowledge, after understanding the camera must have a deeper understanding of the focus system.

Automatic coke force can be updated through toughness

Isn't the ability to focus a camera determined when it's out of the factory? Generally speaking, it is true that what AF module the camera is equipped with determines what autofocus function the camera will be able to have. Sometimes, however, there are cameras that, despite their newly developed autofocus module, cheap canvas printing may be commercially determined to initially select the ability to "seal" part of the camera, wait until the appropriate time, and then "release" it with a new firmware. Like in the first half of this year, Canon released the EOS 70D's highly acclaimed dual pixel autofocus system on the C100 and C300 cameras through a paid firmware update.

What is a tough body? Why is it so amazing? Firmware is actually a small software program, controlled by microchip processors, main function and operation control products, at present most cameras product design, takes the form of can update the firmware, in the period of the use of the products, so that if the compatibility with other peripheral products or function problems, panoramic canvas can be used to update the firmware way adjustment, or new features like the release of the mentioned above products.

Previously the Canon EOS 5D Mark III's central focus would have worked for lenses with a maximum aperture above f/5.6, but with an extender the maximum aperture for a lens like 400mm f/5.6 would have been reduced to f/8, whereas the central focus would have failed. For this, Canon is to take the method of brake update to solve the problem. Therefore, after buying a camera, you can also pay more attention to the official website whether there is a corresponding type of firmware update, can pre-eliminate some possible functional problems.

There's a problem called focus shifting.

Perhaps a lot of players here have had the problem of shifting focus, clearly before shooting the focus, why shoot out or paste? When self technical factors such as hand shock are excluded, it is possible that the focus shift occurs. Before talking about "what is a shift focus" mentioned in the article, move the focal is divided into two kinds, one kind is due to the variation in structure design and produce in camera, will bring in some advanced models "af fine-tuning" function, let the user can according to different lens focal length fine-tuning, and the corresponding data memory in the camera body, also can be combined with lens corrector to solve the problem.

If the camera itself is fine, it's probably due to the lens structure itself, especially with large aperture lenses. Because the large aperture lens always operates under the condition of open aperture when it is in autofocus, because the aperture aperture lens is large, the edge of the spherical mirror is prone to aberration, which causes the error between the focus judged and the focus actually reduced when shooting, resulting in the focus deviation. In such a situation, it is suggested to narrow the aperture to make the depth of field deep enough to accommodate the focus deviation.

The autofocus system is more sensitive and accurate in horizontal direction

Most of the autofocus systems in today's digital monocular cameras are basically equipped with a font type of autofocus sensor, which has been developed into a cross or double cross type of autofocus sensor. If you look at the automatic focus distribution of some monocular cameras, you will find that the linear focus sensors are mostly arranged in a vertical way, so they should be more sensitive in the vertical direction. Wrong. These sensors, though aligned vertically, are more responsive to horizontal lines. In this case, the performance is more obvious when chasing the focus. If the shoot is moving in the horizontal direction, the success rate of chasing the focus is higher. But if up or down or before and after, relatively easy to appear slow or catch the focus of the situation.

Use pan focus to take a sharp and clear image

Pan-focus technique is more commonly used in landscape photography. In order to ensure the overall clarity of the shooting picture, the scenery beyond a certain distance or infinite distance will be selected for focusing, in order to bring the scenery in the shooting picture into the depth of field in advance to save the focusing time, also known as "hyper focus photography". In fact, pan-focus does not have to be at an infinite distance. It can be measured by depth of field meter, mathematical formula, online tools, or even a special APP for reference. But if you don't have a measurement tool, the laziest way to do it is to narrow the aperture and manually select the focus to fall to an infinite distance.

In the past, large canvas prints some old manual lenses will be printed with a depth of field meter for the user to focus on the reference, but now most automatic focus lenses have been relatively rare, here not to repeat, interested friends can refer here.