Cant focus well...

[Jamshu 0]

Hi.

I have 8 security cameras from aliexpress(AHD)

Its ov4689+nvp2450

Varifocal 2.8-12mm

And I cant focus well the cameras

I think it Fixed Iris and that the reason.

I tried to put nd filter of 0.6 in front of the camera, and the focus looks much better.

But I cant put the nd filter well... I need maybe to stick the filter on the glass(Dont know how)

Maybe there is a better way to change the aperture or something?

Thanks for the help guys..