I'm recording a top view of a drum machine with this camera: Panasonic HDC-TM40. I need to use manual focus to fix the focus.

  1. Using manual is the only way to lock the focus, right?
  2. I can barely see the manual focus with the little screen (and even with an external screen). May I zoom in, focus, then zoom out (optical zoom only)?

1 Answer 1


To answer your second question:

You can only use the zoom in, focus, zoom out if the lens is parfocal. Normally a parfocal zoom lens starts at 3000-4000 USD, thus I highly doubt the lens in this camera is parfocal.

Then again, how much of an issue this will be depends entirely on the lens, perhaps it won't loose a lot of focus or it will loose a lot of focus when you zoom out.

I'm not familiar enough with the camera to really answer your first question, but in general terms manual focus is the only way to lock focus. However, modern auto focus in certain cameras keep focus very well, but it isn't locked as such.

  • Thanks for that. I'm guessing it's not parafocal, but the manual focus is not that granular, so I'm guessing that I'm not losing much focus when I zoom out. Regarding focus lock: the autofocus goes mad in this type of filming, since my hands are moving on the drum machine... I want to fix the focus on the machine. Here's a video I did with autofocus, which is quite terrible (ignore the audio issues, too): youtube.com/watch?v=cB1I8WRsjrI&t=87s Commented Apr 27, 2017 at 14:39

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