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Autofocus not working with Orbit AF
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By:
HilmanC
Rank:
Newbie
Topics:
0
From:
n/a
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Added:
04/25/2008 - 10:01 AM
Hello,
I just setup Abelcam for the first time. Everything is running fine except autofocus is not working...I go into webcam config -> Source tab, I see that white balance and focus are set to auto but the white balance slider would jump around and the focus slider only stays at 153 forever.
I cannot even manually adjust the focus on the cam...
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By:
MelvinG
Rank:
Magna Cum Laude
Topics:
661
From:
Los Angeles, USA
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Added:
04/26/2008 - 08:52 AM
I have 2 Orbit AFs here and they both do the same thing, regardless of what software I am using at the time. The Autofocus just "quits" sometimes. Usually I can get it working again by un-checking Auto, moving the Focus slider around a bit and then re-checking Auto. Because it happens with software other than AbelCam I've pretty much concluded it's an issue with Logitech's driver.
FWIW, it seems like Autofocus fails a lot more frequently in low light conditions. I tend to suspect, but have no proof, that when the light is dim the autofocus gets confused and gives up.
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By:
HilmanC
Rank:
Newbie
Topics:
0
From:
n/a
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Added:
04/26/2008 - 09:53 AM
I see...I'll give that a try, thanks
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By:
HilmanC
Rank:
Newbie
Topics:
0
From:
n/a
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Added:
04/27/2008 - 02:50 AM
Ok, I tried disabling the Autofocus and manually playing the focus on the Abelcam software config.
I think Abelcam implemented the focus values in reverse. When the focus value in Abelcam config is 0, it is actually infinity focal length in the webcam and when the focus value in Abelcam config is 255, it is actually the lowest focal length in the webcam.
The autofocus goes crazy because the close loop control algorithm in the driver cannot find the right focal length. It may have to do with the focus values being in reverse...?
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By:
MelvinG
Rank:
Magna Cum Laude
Topics:
661
From:
Los Angeles, USA
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Added:
04/27/2008 - 11:26 PM
I preface this reponse with the disclaimer: I did not write AbelCam, SSE did. I am a software developer myself, but as regards AbelCam I am just a user. Thus there is a chance I could be wrong! 
I understand your line of reasoning: if the control value range was inverted, the control loop would go crazy because every attempt to improve focus would actually worsen it.
Where I see a flaw in your reasoning is that I don't believe AbelCam actually implements the autofocus in any way. When you hit the Source button AbelCam is just calling a function on the driver's API and it is the driver that generates the dialog box and all the controls in it. This would be consistent with my experiences working with other sorts of drivers.
I somewhat confirmed this today by shutting down my AbelCam and then running WMCap. I set WMCap to use one of my Orbit AFs, then opened the equivalent dialog for the cam (Options -> Video Capture Filter...). The dialog looks identical to the one I get when I hit Source in AbelCAm, suggesting it comes from the same place. More to the point, the focus behaves the same way (0 = infinity). And, it stops autofocussing after while.
If you'd like to reproduce my experiment, go to Microsoft's site and search on either "wmcap.exe" or "amcap.exe". Same program, 2 different names. It's a very basic DirectX vidcap utility that is great for testing cams, etc. Anyone who works with USB cams needs a copy of it on their system.  |
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By:
JavierG
Rank:
Newbie
Topics:
5
From:
USA
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Added:
07/10/2008 - 10:27 PM
I found out that AutoFocus only works on the Orbit AF when I select "Follow Me" or "Follow Me and Others" from the Logitech software. If you turn Follow me on and then turn it off, autofocus will still work in the fixed position the camera is in. But as soon as you move the camera manually, autofocus will stop working. This is definitely a logitech driver bug. It seems the "Follow Me" feature is required to be turned on for auto focus to be working all the time. Once that feature is off, the driver ignores turning auto focus back on after the pan tilt is activated once.
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By:
MelvinG
Rank:
Magna Cum Laude
Topics:
661
From:
Los Angeles, USA
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Added:
07/13/2008 - 10:06 AM
That's some good info, Javier - thanks!
Your post got me interested in my AutoFocus again, after having given up on it ages ago. I didn't come up with any solutions, but I can say mine acts exactly like you describe (with driver ver. 11.7 here). I used AMCap/WMCap instead of the Logitech software, and used the "Face Tracking" buttons and the Pan/Tilt arrows in the Video Capture Pin dialog to run the test.
Guess we have to wait for Logi to fix the driver. Maybe when they get to ver. 36.4.0.4321?  |
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By:
DomenicoS
Rank:
Forum Addict
Topics:
59
From:
Croatia
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Added:
11/04/2008 - 03:21 PM
Hi
What is the status with this problem at this moment?
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By:
MelvinG
Rank:
Magna Cum Laude
Topics:
661
From:
Los Angeles, USA
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Added:
11/04/2008 - 11:41 PM
As far as I can see, nothing has changed. I just checked Logitech support site - they have not released a new driver in more than a year.  |
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By:
JoergR
Rank:
Frequent User
Topics:
34
From:
Germany
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Added:
11/14/2008 - 03:01 PM
For some time now I have the feeling that my cam pictures are not very sharp in long distances.
I'll also play a bit with this follow-mode. Maybe it helps...
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By:
JoergR
Rank:
Frequent User
Topics:
34
From:
Germany
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Added:
11/16/2008 - 03:46 PM
Obviously my autofocus works always.
turning on face-tracking is no option cause it disables pan/tilt completely.
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