Hi Laurent,
On 31/05/11 22:32, Laurent Pinchart wrote:
Hi Sebastian,
On Friday 29 April 2011 21:17:07 Sebastian Arcus wrote:
On 04/29/2011 09:56 AM, Laurent Pinchart wrote:
On Wednesday 27 April 2011 10:42:14 Paulo Assis wrote:
1. Would this be fairly specific to the Logitech QuickCam 9000, or is a
more generic issue with webcam sensors?
Neither, you just need to lower exposure time.
2. Are other webcams better in this respect?
I don't think so, you can control exposure quite easily with this cam.
3. Can I use any of the UVC features to tweak the driver parameters in
order to force sharper images of objects on the move?
Yes, just set exposure mode to manual, and tweak exposure absolute,
also remember to disable "exposure, auto priority".
You should also use the highest fps possible (30 fps I think)
4. Is this to do with the auto-focus of the camera, and can I turn it
off or peg it in software at a certain value, to improve things?
Yes, use uvcdynctrl (command line) or guvcview (gtk) (guvcview
--control_only will let you use your program along side it)
As far as I know, auto-focus for the Logitech QuickCam Pro 9000 is
implemented in software in the Windows driver. The camera has a manual
focus control only. You can tune it with any V4L2 application that
supports controls, such as uvcdynctrl, guvcview, v4l2-ctl, yavta, ...
I've had a look and it indeed there is a focus control. Considering that
by default it is set on 0 (and it was set on 0 during operation), does
this mean that it is on auto?
No, the camera doesn't implement auto-focus. Which focus control does your
camera report, absolute or relative focus ?
I'm not sure any more. The cameras are actually installed on a bus, so I
don't have them here to test the. They are part of a cctv system I've
built to be installed on the bus. However, in practice, in normal
daylight - it seems that there is no motion blurring. So the results are
very good so far without needing to adjust the focus controls in any way.
Thanks for all the answers.
Sebastian
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