Accuracy problems: is it normal?

[fmortz]

Hi,

I have received my SmartNAV4 EG today, and I have some questions. I have a dual screen configuration: a 1920x1200 laptop and a 1680x1050 external monitor. I have placed one circular reflective dot in the tip of a head microphone, which is at about 85 cm from the camera.
With default and default_fast profiles I could not access the whole main screen by moving the head naturally (I have no physical problems with my head), and I had to increase the speed to 12 so I could cover only the whole main screen without forcing my head movements. The other settings are as default: relative positioning, etc. With this speed, I have precision problems which in the end cause some neck pain, and suprisingly some sea-sickness feeling.
Checking the camera view, I see that, when moving my head in the whole confortable range, the dot only moves about 1/10 of the whole space, and even moving my torso from side to side I can�t get it past 1/2 of the whole camera screen. I feel that I'm not using the whole camera resolution (maybe only 1/10), and that is why I have low accuracy. Is the behaviour I'm describing normal? Is there any way in which I can improve it?. Thank you for your help.

Regards,
Fernando Molina

[NaturalPoint - Mike]

There are a few things you could try to increase the usage of the SmartNav field of view. First, try putting the dot on your forehead or the brim of a hat. Because the pivot point of your head is the base of your neck, the farther away from that point the dot gets, the more movement it will have.

Additionally, you could try moving the camera closer, if at all possible.

[fmortz]

Hi,

First, thank you for your suggestions. I have tried putting the dot in my forehead and got no noticeable horizontal gain (vertical was a little bit better), which can be explained because the microphone is a little farther than my forehead from the axis when I rotate from left to right (like saying 'no'), but it's closer from the axis when I move my head up and down (like saying 'yes'). I have tried pivoting my head also for lateral movement (like bringing my cheek closer to the shoulder), so I had more movement with the dot in my forehead, but I feel strange when looking at the screen this way.
I think that the brim of a hat would be best, but I don�t have a hat for testing, and maybe it would not be confortable with the big headphones I use. Nevertheless I plan to get a long hat and try it.

I have done some informal measurement and testing, and, if I want the dot to move 2/3 of the camera's width, I have to get as close as 30cm and move the dot as much as about 15cm (with the dot in the microphone I have to rotate my head so far that I can�t see the screen). At the recommended shortest distance of about 60cm and simulating the brim of a hat, I estimate I'd need to move my head about 45� to each side to have the dot to travel about half of the camera's screen. Moving the head that much makes looking at the screen very difficult. Maybe I have done my measurements incorrectly (I can only use one hand and I have not removed the camera from the top of the laptop's screen), and I'm sure you know better than me, but I'm puzzled because I think that the camera's lenses should be calibrated so that a reasonable head movement covers nearly the whole camera's field of view at the best recommended distance (or maybe the shortest), so the usage of the resolution of the camera is improved. I am no optics expert, so probably I'm missing something. Maybe doing it as I suggest would require the user to be exactly facing the camera, and you have decided to give more freedom in this at the cost of less accuracy. I personally would prefer more accuracy even if there are more restrictions in the camera/head positioning. If I understand it well using a hat as recommended would be like placing the head closer, which would be like 'zooming' with the lenses, which would limit the vertical and horizontal range in which I can place my head.

In my setup I use one of the suggested dot positions, although not the recommended, and I'm well within the recommended distance, more in the closer range, but the dot moves so little in the camera that initially I thought that the hardware had some problem. This lack of accuracy at normal distances will probably make me reduce my SmartNAV usage to avoid neck pain (well, I still need more training). Although the product is usable (actually it's much better than the other solution that I have tested, which used image recognition alone with a standard webcam), I believe that there is still room for improvement.
If you have kept reading up to the end, thank you for your time

Regards,
Fernando Molina Ortiz

[NaturalPoint - Mike]

What vertical and horizontal speed settings did you use in the above experiment?

Have you tried it on the bill of a hat?