Photo tricks. Part 12. Focus Trap

The focus trap is an interesting feature to catch the desired subject in focus without focusing itself.

Photo tricks. Part 11. Focus Trap

Photo tricks. Part 11. Focus Trap

The focus trap is also called focus trap... The essence of the reception is very simple, the camera focuses at a certain distance, and then waits for something at this distance to come into focus, that is, to fall into the so-called 'trap'.

First, how to configure:

If you have a professional-grade camera, such as Nikon D300, D700, D3s etc., which has a special AF-ON button

1. Set the 'AF activation' function from the 'Autofocus' menu item to 'AF-ON only'. In this position, auto focus is only available when the AF-ON button is pressed, and the shutter button when pressed halfway will activate metering exposurebut will not auto focus. This is the standard focus mode for professional photographers.

2. If using the AF-S focusing mode, set the focus priority in the camera menu using the 'Priority selection' menu item. for dir. AF-S 'to' Focus'. When using focus mode AF-C, then in the camera menu set the focus priority using the 'Select priority. for dir. AF-C 'is also set to' Focus'.

3. Set the focus mode on the lens to the auto focus position. Focus in any way at the desired focusing distance, press the shutter button all the way, and wait until an object appears in the focusing area, as soon as the subject gets into the 'trap', the camera releases the shutter.

If you have an amateur level camera such as Nikon D5100, D60, D80 etc., which does not have a separate AF-ON button

1. Using the camera menu, configure the button AF-L / AE-L to 'AF: AF-ON'. It's good that all Nikon cameras have this button and can always be reprogrammed. After this setup AF-L / AE-L button will simulate the operation of the AF-ON button on older cameras. When you press the AF-L / AE-L button, the camera will automatically focus. Auto focusing by half-pressing the shutter button will not occur.

2. Put the camera in focus mode AF-S or AF-A. Unlike professional cameras, almost all amateur cameras do not have the ability to prioritize focus, in AF-C trigger priority always works, and in AF-S mode, focus priority always works. Features of amateur cameras described here.

3. If the camera has the ability to set the focus priority for AF-S, AF-C modes, for example, such a function is in the amateur camera Nikon D5100, then you need to set the priority 'Focus' for such modes. If you don't want to set priorities, on amateur cameras just turn on the mode AF-A.

4. Set the lens focus mode to auto focus mode. Focus in any way on the desired focusing distance, press the shutter button all the way, and wait until an object appears in the focus area, as soon as the object falls into the trap, the camera releases the shutter.

Attention: Some new Nikon cameras cannot be set to focus trap mode. A reliable list is not known.

The focus trap works in any focus mode: one point at a time, with dynamic focus area selection and normal auto mode. Best to use a trap in single-point focus mode or with dynamic focus area selection.

Where to apply?

The focus trap can be used to easily catch moving objects.

Example: at motorcycle competitions everyone knows where motorcyclists will pass. On a tripod, we focus the camera on the place where we want to catch a motorcyclist. Press the shutter button all the way and wait for the rider to fall into our focus trap. With the usual focusing method, the focusing speed of the lens will not always help to quickly respond to a changing situation. In general, there are many examples.


The focus trap is an interesting way of working with a camera. With the help of the trap effect, you can simplify the shooting of dynamic events, or make manual focusing easier. I advise you to do your own research.

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Material prepared Arkady Shapoval. Please, if this material was useful to you, help my project. And don't forget that everyone can write your review for one or another photographic equipment.

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Comments: 261, on the topic: Photo Tricks. Part 12. Focus Trap

  • Eugene

    The trap works like this: Focusing AF-S S (one point at a time). Focus shooting priority. But the main condition is the presence of A / M focus mode on the lens. Only then, by turning the focus ring, holding the focus point on a specific object (or at the place where this object is expected to be), holding down the shutter button completely, the shutter will be released at the moment of focusing on the selected point. In mode M, this no longer works (descent into milk). Just as it does not work with all other combinations of settings. D750 and 24-70.

    • Arkady Shapoval

      there are cameras that, in principle, cannot implement this function

  • Sergei

    Good afternoon!
    such a thing
    Nikon d5300 camera, nikon dx vr 18-55 lens (without any buttons except to remove from the block and select the focal length with the ring)
    So I switched the ae-l button to AF-ON mode
    in the menu there is an item “Priority selection for AF-C” Focus is selected (there, if you click on the ? sign, it says right in the description that in AF-C mode “The shutter can only be released if the camera has focused.“)
    in the camera on the slave screen is selected in AF-C focus mode (although I tried AF-S and AF-A)
    but the camera stubbornly takes a photo without focus, it’s purple from the word at all
    firmware version C 1.03 L 2.018

    I have a suspicion that this is due to the lens itself, but I don’t have others yet ... has anyone come across something like this?

    • Sergei

      and yes it was in the settings focus on one point ...

    • Alexey

      The same nonsense on the d5600, the camera is purple that focusing is a priority.

    • Nicholas

      Had the same problem. There is only one solution (what I found for myself) - a fast lens (F / 1,4 or extreme case 1,8)
      Those. You need a very shallow depth of field. It works on 2,8, but there are a lot of false positives, and the background must be at a decent distance. And yet, the AF-S mode. B AF-C did not achieve success.
      Try temporarily deactivating AF-ON. Good luck.

    • Nicholas

      And one more addition on long lenses works with large apertures. It does not work at wide, the camera always thinks that it is in focus. Those. small, very small IPIG is the key to success.

    • Alan

      I have the same problem, it’s easier for me to hold down AF-L at the right moment, already fixing the focus, than AF ON which completely ignores the focus and continues to shoot until I can focus through it again. I also tested it on a Sony a6400, same problem, I don’t see the point in AF-ON

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