Traditional Culture Encyclopedia - Photography and portraiture - How to use the DMF function of Sony camera? Can I manually focus the ring after half pressing the shutter? That's what I did. What about the manual focus ring after half pressing the shutter?

How to use the DMF function of Sony camera? Can I manually focus the ring after half pressing the shutter? That's what I did. What about the manual focus ring after half pressing the shutter?

DMF: Full-time manual focusing

When the lens with full-time manual focusing function is used, even in the auto-focusing mode, the focus ring can still be directly rotated for manual focusing without worrying about the damage of the lens focusing system. This function is called FTM for Canon and DMF for Sony.

Sony also has a full-time manual focusing mode of the fuselage, that is, the coupling link between the fuselage and the lens is automatically cut off after a single focus. Coincidentally, Pentax has a similar technology, except that the clutch device is placed in a part of the lens and is not limited by the fuselage.

For macro, extremely high-precision focusing is required, and the camera's own AF may not be reliable. Before DMF technology appeared, users had to use MF for fine focusing. For most cheap lenses, the distance from the nearest focus to the infinite focus is very short (generally, the focus distance can be completed by rotating 45 degrees), so the benefits of DMF have not been realized. However, for advanced telephoto lenses or macro lenses, it is generally necessary to rotate 90 degrees or even more than 180 degrees to complete the focusing distance (I actually like to use this kind of lens, macro photography focuses, and often the focus will be deviated at the moment of breathing, and a lens with a long focusing stroke is very beneficial to fine focusing). In this case, DMF can play a huge role. Users can quickly aim at the parts with large contrast on the target object with ultrasonic motor (for example, when shooting pandas, they can focus on the ears first, because the contrast between the ears and the background is large, which is generally the case, so I have nothing to say), then manually correct them with DMF, and finally shoot the focus with small contrast (eyes, panda eyes and eye sockets are all black, and the contrast is very small).

Because the switching between AF/MF is omitted, the focusing speed and accuracy can be greatly improved and satisfactory photos can be taken. It should be pointed out that the mechanism of DMF determines that manual correction focusing must be carried out after AF is completed, so continuous focusing and DMF cannot be used at the same time.