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NX300M lens oscillating in autofocus mode

Started Jul 10, 2020 | Discussions
luizcrf New Member • Posts: 4
NX300M lens oscillating in autofocus mode

Hello, does anyone know why the lens of the samsung nx300 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.

Samsung NX300M
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markyboy81 Veteran Member • Posts: 4,778
Re: NX300M lens oscillating in autofocus mode

luizcrf wrote:

Hello, does anyone know why the lens of the samsung nx300 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.

I only owned the 18-55mm for a short while but I have experienced what you're describing with several NX lenses, including the 16mm,20mm and 30mm. I think it's just the nature of the focusing system that it pulses in and out.

The 16-50mm pz is better in this regard, it's far more suited to video.

Another alternative is to lock the focus during video and release when you need to regain focus.

 markyboy81's gear list:markyboy81's gear list
Sony ZV-1 Samsung NX1000 Samsung NX3000 Samsung NX1 Samsung NX500 +9 more
kypfer Contributing Member • Posts: 985
Re: NX300M lens oscillating in autofocus mode
1

That's just good old-fashioned low-light failure of the auto-focus system.

Working against a textureless white background with nothing for the camera to lock onto won't help.

Get some more light onto the subject and/or use a wood-grain or fabric surface and the problems will go away

 kypfer's gear list:kypfer's gear list
Pentax *ist D Pentax *ist DS Pentax *ist DL2 Pentax K200D Samsung NX5 +7 more
OP luizcrf New Member • Posts: 4
Re: NX300M lens oscillating in autofocus mode

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?

kypfer Contributing Member • Posts: 985
Re: NX300M lens oscillating in autofocus mode

luizcrf wrote:

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

Every time the original video oscillates there is nothing but blank white table in the middle of the picture! The camera is trying to find something to focus on but it can't see any detail. Try again with a textured background or use manual focus.

 kypfer's gear list:kypfer's gear list
Pentax *ist D Pentax *ist DS Pentax *ist DL2 Pentax K200D Samsung NX5 +7 more
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