Problem in autofocus mode nx300m

[luizcrf]

Hello, does anyone know why the lens of the samsung nx300m keeps making these oscillations
in the footage (back and forth) .Whenever I put it in "autofocus" mode, it seems like she tries to focus on the object, but she can't, so she keeps going back and forth several times.

You can see these oscillations in the video below (seconds 0: 08,0: 29 and 0:52)

https://www.youtube.com/watch?v=4LCSCxi0ZXs&feature=youtu.be

The camera is excellent, but this defect in the focus is terrible and spoils the footage. Does anyone know if it is possible to solve this problem?
I've tried several types of settings and I can't solve this problem. I used 18mm, then zoomed in 24mm, 45mm and lastly 55mm. I changed autofocus from automatic to continuous and etc.
I changed the ISO, increased the lighting, the aperture mode, the zoom, but nothing worked.
Is this a feature of the 18-55mm lens?
If so, do you recommend any other lens that is compatible with the nx300 that does not have this same problem?

Thank you!

Camera specifications:
Nx300m
Lens: 18-55m
Continuous automatic focus
Iso: 1600
1/30
Video shot in a 2mx2m room with four 25w lamps on the ceiling.

[Rodbender]

I see you have asked this question on some other sites and so far no real help offered. Samsung seem to have an auto focus problem with other cameras too. Google and there are others asking for help regards this issue. Personally I would try increasing the lighting and use a textured background for your videos. Seems to me camera is searching for something to lock on to and low lighting ie a total of 100w is not enough for the camera to function correctly. Samsung cameras seem, according to the reviews I have read, have low light autofocus problems. A textured background may give the focus system something better to lock on to.

Change the area camera focuses on. Keep subject in selected area. It appears that the problem occurs in your video when the centre of your image is clear of objects, ie camera is focusing on background. Just my penny worth, hope it helps.

[luizcrf]

Hello, I understand, and thanks for your help. The problem is that I recorded this video in a 1.5 meter x 1.5 meter room with 4 25w lamps on the ceiling. The camera was set to F / 3 aperture ( also tested in F5.6 eF10) and ISO 3200. The result was this video.

The recommendation was that I increase the lighting. So I added (in addition to the 4 lamps of 25w), plus 2 lamps of 135w (5500k). Even so the problem persists.

I varied 18mm, 25mm, 35mm and 50mm. The problem continues.
Is this a feature of the camera?

[mikew]

With things like this taken from your vid i dont think the camera can be expected to know what you want in focus, It needs manual focus or a small focus area selected.

Even at small apertures DOF will be shallow so the camera could start hunting between things it sees as nearly in focus