To highlight just a clothespin on the other you may need to modify specific digital cameras modes. You may need to reduce the depth of field, using a focal length of 150mm and an aperture of f / 5, which is the most you would leave me open the target in these conditions and I focused exactly on the clip I wanted to highlight.
There are many settings to select from. Another typical example is taking a photo of a dictionary word. In this case the focal length is 50mm and the aperture is f / 2.8. Although the idea is not original serves to see how we can highlight only the word Detail of the rest of the photo using the selective approach. The tools we have to play with selective focus are all those that modify the depth of field (distance to subject, focal length and aperture). We may also use shift lenses.
This type of digital cameras lens changes the perspective and can greatly affect the depth of field, exaggerating even more. The trigger is an accessory that replaces the shutter of the camera when shooting. It enables you to shoot without moving the camera and on the other hand to shoot remotely. There are basically two types of triggers, cable and remote. The former are cheaper. The most advanced program allowing even when shot.
When to use a trigger? Most DSLR digital cameras have a shooting mode called BULB. This method is used in the program manual and is relative to exposure time. Using this mode will be getting the picture while the shutter is pressed. Triggers are essential to use this mode for two reasons, to not move the camera and to keep you glued to your finger left it for life. Most of these triggers can block the trigger, so it is not necessary to be constantly pressing the button and the shutter does it for us. Imagine doing this photo night for 2 ½ minutes by pressing the button.
But also use the trigger on those occasions that we want to be away from the camera, either to appear in the picture or to manipulate the elements of the scene. Use the self timer on the camera as an alternative.
When we use a long exposure time, but outside the BULB mode the digital cameras will be able to control it and need not be constantly pressing the button. We can use the self timer on the camera to shoot and avoid moving the camera.