guykuo
Getting comfortable
The SD1A203T-GN Mini PTZ is mechanically limited to -5 degrees vertical tilt even when you increase its limit from the factory default. At -5 degrees, you start to see the camera's black horizontal housing. Even worse, objects that are near zero degrees tilt or higher are optically distorted by the acrylic dome. At higher zoom levels, the distortion is worsened. The acrylic dome has its sphere/cylinder transition at about 0 degrees (horizontal). That is why near horizontal objects were vertically doubled or blurred in the stock unit.
Because many areas of interest across the street are at the horizon or higher, I wanted this PTZ to be able to look further up and have a clear image near the horizon. I have quite a few of the larger PTZ that can look -15 degrees, but this particular location could only support a mini PTZ. What is one to do? Mod the PTZ camera, of course. This requires taking the camera PTZ mechanism apart and if you break it, it's your fault. Actually, if anything breaks later on, it's still your fault. So you might not want to do this. I'm presenting it here because it solved my problem and got the performance result I wanted.
The camera mechanism now tilts from approx 85 to 0 degrees vertically rather than 90 to -5. The camera was also lowered further into the dome by 1.5 mm to move the optical distortion further up the visual field.
Here is a after/before of the same area. You can see that things near the horizon are now more clear. What you can't see in this image is that the camera in the pre-mod was at max vertical tilt, but the post mod is a bit less than max vertical tilt (to point at same target)
Look at the garage door (right side of image) in the original. You see optical doubling. In the post-mod image, that doubling effect is up at top of hedge level. It's not gone, but I have shifted it upward and away from my areas of interest (near horizon)
Because many areas of interest across the street are at the horizon or higher, I wanted this PTZ to be able to look further up and have a clear image near the horizon. I have quite a few of the larger PTZ that can look -15 degrees, but this particular location could only support a mini PTZ. What is one to do? Mod the PTZ camera, of course. This requires taking the camera PTZ mechanism apart and if you break it, it's your fault. Actually, if anything breaks later on, it's still your fault. So you might not want to do this. I'm presenting it here because it solved my problem and got the performance result I wanted.
The camera mechanism now tilts from approx 85 to 0 degrees vertically rather than 90 to -5. The camera was also lowered further into the dome by 1.5 mm to move the optical distortion further up the visual field.
Here is a after/before of the same area. You can see that things near the horizon are now more clear. What you can't see in this image is that the camera in the pre-mod was at max vertical tilt, but the post mod is a bit less than max vertical tilt (to point at same target)
Look at the garage door (right side of image) in the original. You see optical doubling. In the post-mod image, that doubling effect is up at top of hedge level. It's not gone, but I have shifted it upward and away from my areas of interest (near horizon)
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