Focusing with video on a pen

Another quick question if anyone might be able to help. I find when using my epm2 with 17mm for video that the lens likes to refocus quite a bit. This is often pretty quick but sometime inside there can be some searching.

What is the best way to avoid this when doing video? Can I somehow lock off the focus and stop it hunting regularly?

Anyone?

I usually do video with manual focus enabled. Having the scene squiggle in and out is distracting. I have to focus in stills mode and switch over to video.

This can be unwieldy with some of the PEN's, like the EPM1.

If I don't want to manual focus what is the best autofocus setting to use?

HDcamfan said:

HDcamfan wrote:

If I don't want to manual focus what is the best autofocus setting to use?

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Using CAF but decrease the aperture to allow more room for auto focus confirm, remember the shallow depth of field is what causes the focus system to balance in an out of focus. All contrast auto detect systems do this but most others are extremely slow and you don't notice it because of the smaller sensor creating larger depth of field. The only other option is SAF+MF, manual focus 90% of the time and auto focus, half press, when you need snap focusing.

That makes sense. For video as a rule of thumb could you suggest an rough appropriate aperture to use inside and outside.

I appreciate it will be different depending on lighting but any experienced advise would be great.

For video you want your shutter speed to be around 1/60th and it can be as low as 1/30th because the PEN only uses 30 fps for video (even with 60i).

This would allow you to use a smaller aperture. I would stay at F/11 or lower though.

HDcamfan said:

HDcamfan wrote:

That makes sense. For video as a rule of thumb could you suggest an rough appropriate aperture to use inside and outside.

I appreciate it will be different depending on lighting but any experienced advise would be great.

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It's going to depend on lighting like you said. Keep in mind that the 1920x1080 output is significantly smaller resolution than the full sensor size so diffraction is a non issue because it can't resolve that much detail to begin with. Assuming daylight I would recommend f8-16 depending on what it is your trying to capture. Use focal length to assist with subject isolation rather than aperture alone. Video has so much more detail involved because everything is flowing so keeping more in focus is often better than less unless your being very specific about what your capturing. With that thought in mind, f4-f8 indoors in a well lit environment is best. The only time to use f4 or less for video is when your being very specific with your recording or when the lighting is such that it requires it.