PTZ IR Mode On Manual Focus Doesn't Remember Focus Point

P

PTZControllerSA

n3wb
Oct 6, 2025
6
4
South Africa
Hi,

I have around 40 presets at night 100m+ away.
I have saved the preset when the picture was in focus.

However, every night, it is out of focus again. Not terribly out of focus, but the picture is not sharp.
And if I set it to auto focus, it goes WAY out of focus.

What do you suggest?

I'm pointing the camera at a riverbed with wildlife on the other side.

Dahua - DH-SD6CE225DB-HNY
2MP 25x Startlight IR Network PTZ Camera
Powerful 25x optical zoom.
Starlight Technology.
Max. 25/30fps@2MP.
IR distance up to 250 m.
Deep-learning-based perimeter protection.
SMD 3.0.
PoE+.
IP67, IK10.
Click to expand...

Settings:

1759772119683.png
1759772159833.png
 
Did you save the preset at night? Focus can be different in color vs B&W/IR

Also I'd look at reducing DNR. Its got to be a pretty soft image with it that high making it difficult to focus

Also when you set focus, the default step is 20, set it to 1 before you focus. This gives a much finer control of the focus point
 
Last edited:
Then Id start with reducing DNR and setting focus with 1 step instead of the default 20
 
Can't see the attachments..

It may be called "Speed" should be a setting right where you are using the Zoom/Focus from 1-20

Also I just noticed 1/12 exposure. Coupled with the really high DNR its going to be very very soft at night. This could hurt the cameras ability to get a clean focus
 
Ah, ok I see it. It was on the middle point. So I've changed it to slow:
1759773553471.png

I've also reduced the DNRs to a much lower level.

1759773714143.png
Anything lower than that, it's very grainy.

Should I do semi-auto? Or, what does that mean?

But, it's actually a lot better already!! Auto focus is working a lot better with the DNR lower.

Thank you!!
 
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Yep try that first and then see if you can increase the exposure to at least 1/30
 
So, just to understand the algorithm, when DNR is high, the picture is just so smooth, the autofocus algorithm struggles to find sharp edges?
And when the speed is high, it is more likely to overshoot past the right focal point, and therefore, it will struggle to find the focal point?

Thanks again!
 
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Reactions: bigredfish
Generally speaking yes.

I'm sure there are others who have deeper technical knowledge, but those seem logical to me having played with them for some years.
 
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