A new experiment that works.

Started Aug 9, 2010 | Discussions thread
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brandrx Forum Pro • Posts: 28,337
A new experiment that works.

Tripod mounted Catch-in-focus (for hummingbirds) using autofocusing lenses that do not have the AF/MF switch on the lens.

The method below will not work with a Pentax K2000/K-m or a Pentax K-x. I made it work with a Pentax K10D, Pentax K200D, Pentax K20D, and a Pentax K-7.

So far I have only tested a DAL 18-55mm, a DA 50-200mm ED, an F-35-80mm, and a Tokina AT-X SD 400mm f5.6 AF. For now I am going to assume that it will work with any autofocusing lens. This solution is not required if the lens is a Pentax and has an AF/MF switch on the lens.

Remove the lens and short out the data pin, using aluminum foil, on the camera body. The data pin is the bottom pin as you are looking into the camera. Now when you turn the camera on it will ask for the focal length, but only if you have shake reduction (SR) turned on. The wide open aperture will probably read wrong at the camera but you can experiment with settings for a good exposure.

In the menu set the Catch-in-focus = 2. Set the Auto power off = OFF. In the Fn menu set Continuous shooting to on. On the side of the camera set the AF-S/AF-C/M switch to AF-S. Set the Mode dial to Av. Set the focus point to Center. Attach a locking wired remote. With a Quick-shift type lens just manually adjust focus to where a future subject (hummingbird) will be. Without Quick-shift then hold the lens removal button in while half pressing the shutter and focusing the lens to the point where the future subject will be. Press and lock the wired remote. Now when a subject enters the prefocused center area the shutter will fire. It will continue to fire as long as the subject remains in that area and is in focus. If the subject leaves and another subject comes later and enters the pre-focused area the shutter will fire again. This will continue as long as the battery holds charge or you stop the process.

Would anyone care to verify my findings? Please do.

Heck, now anyone with any lens can do Catch-in-focus (focus trapping) and from this point on no hummingbird is safe from capture.



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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

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