Catch-in Focus function, offered by some Pentax cameras, can be a very useful tool for any type of photographers. Even when using fully manual lenses, like good old Pentax-M or Takumar, you still can enjoy the AF confirmation. Catch-in Focus (or a focus trap) allow the camera to make the shot automatically as soon as the subject will be in focus. This function can really be a time and nerves saver ))
For some manual lenses the focusing is pretty straightforward and not so complicated, but for some (especially with larger apertures) focusing can become a real issue.
At the moment, Catch-in Focus is supported by the following cameras: K10D (referred to as trap focus, has no menu setting), K20D, K-7, K-5, K-5 II, K-3, K-3 II, K-1, K-1 II, K-30, K-50, K-S1, K-S2.
The process will be showed using the Pentax K-3. Please refer to your camera model user manual for menu structure and functions.
How to activate Catch-in Focus function?
If you are using autofocusing lenses, you need to switch them to manual focus mode (using the on-lens switch, if available).
Please pay attention to your focus mode button. It should be at AF or AF.S position. This will allow the AF sensors to work properly with manual focusing. Use the AF.S option only.
Make sure that your USING APERTURE RING setting is set to ENABLE (or PERMITTED depending on your camera model).
Set the AF.S SETTING to FOCUS-PRIORITY.
Also, you need to change the AF BUTTON (in BUTTON CUSTOMIZATION menu) for AF1 ENABLE AF1. It should allow you to use the shutter button for focusing.
Then, go to CATCH-IN FOCUS menu setting and set it (or check the setting) to ON.
Select central point AF (even if you’re using the AF lens). Manual lenses support only central point AF actuation. For AF lenses you may select any point, but bare in mind that central group is more sensitive, especially if you are shooting with open aperture.
Fully press the shutter button and start focusing on your subject. When the subject will be in focus the camera will take the shot automatically.
If you have activated the focus confirmation (with red focus point) for manual lenses, you’ll also see that the point will have the red confirmation signal when taking a picture.
Potential use of this feature
Pentax Catch-in Focus is a handy tool that can help you in many situations.
Macro photographers will, probably, enjoy it the most. As focusing is very tricky and crucial for taking nice shots.
Sports photography, especially for motor sport. Just focus on a place where the car (or a person) should appear and wait for your subject to come to this spot. Picture will be taken automatically when the car will reach the focus point.
Portrait photography with a shallow depth of field. The only issue here is that you’ll need to place your central AF point on a person’s eye (but you can crop the final image as needed).
And other situations when you need to take a picture of some difficult subject. Just press a shutter button and start focusing, trying to let the camera act when it’ll get the focus.
Hope this quick tip was helpful.