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The built-in iSight cam on my MacBook machine keeps re-adjusting the lighting (and focus I think). I need to manually set those, but I found nothing of any use in System Preferences or System Profiler.

Any way to access the settings? Any magic terminal commands that allows access to the camera Anyone has a driver that allows for any camera access?

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I want a nerdy solution, not a commercial app. I don't want to pay for using a webcam! – George Profenza Mar 12 '10 at 2:41
I don't think you understand what webcams are for. – Hasaan Chop Mar 12 '10 at 6:09
-1 for rant. Keep questions clear and concise. – fideli Mar 12 '10 at 6:24
@NSD what do you mean ? What are webcams for ? @fideli - fair enough – George Profenza Mar 12 '10 at 14:10
They're for making college kids really angry apparently. – Hasaan Chop Mar 12 '10 at 23:56
up vote 2 down vote accepted

Doing some work with openCV too and went for the non technical implementation: some tape and black card, and simply covered the light sensor to the left of the camera.

Works perfectly!

The iGlasses solution doesn't address the problem as the brightness/contrast adjustments are performed by the hardware (i think) so it will affect the iGlasses input source and thus output. I imagine you can fiddle with settings to try and alleviate this effect as much as possible although will not combat it completely.

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You may want to try iGlasses. From the website:

Adjust and manipulate your webcam's video settings from within iChat and many other programs, including iMovie, Photo Booth, Yahoo! Messenger, Skype and web-based chat. Apply easy preset settings and fun effects to your video conferences and recordings.

Adjust colors, brightness, and even pan and zoom your Mac's built-in iSight. The picture from your iMac, MacBook or MacBook Pro has never looked so good.

Is your external iSight looking a bit dark? You could install studio lighting, or just install iGlasses to give your videos an instant brightness boost.

iGlasses is a great companion to your iMage USB Webcam. Fine tune your colors for a perfect picture every time.

It's not just for iSight! If you use a Logitech QuickCam or other 3rd-party webcam that uses UVC or the macam driver, iGlasses will add the same great adjustments and features.


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thanks for the link, I did mention nothing commercial. Why should I pay for something that should be in the system preferences ? "iChat and many other programs, " - does that mean I can use this, disable the auto-adjustments and carry on playing with openCV ? – George Profenza Mar 12 '10 at 14:12
Sorry, not familiar with OpenCV. Maybe someone else can help you with a nerdy solution. – fideli Mar 12 '10 at 15:21
George, you may just be out of luck here. I looked long and hard for a similar solution, but found none. I had to resort to getting iGlasses. – ayaz May 20 '10 at 17:24

Maybe your best bet would be Macam. It didn't work for me, but they have active support and probably will add iSight to their list soon enough.

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Using uvc-ctrl &

  1. Prerequisite: install libusb using brew install libusb
  2. Download from sluggo dm9
  3. Download uvc-ctrl-GUI from ppooll
  4. Copy into uvc-ctrl-v0.12b folder
  5. Launch

enter image description here

With my LifeCam HD-3000, the only thing I get worked was to disable auto_exposure..

enter image description here

UVC CAMERA CONTROL FOR MAC OS X (not working anymore but interesting to read)

Here is an interesting article about how to control camera settings:

I also built a simple demo application that makes use of the UVCCameraControl class. This demo uses QTKit to open a connection to the first (default) video device and simply displays the images in a QTCaptureView. There's no system setting to select the default video device, however the device you selected to use in iChat will be the default (you have to quit iChat after selecting your camera, otherwise it will be locked for all other applications).

Here is the download link:

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This currently appears to be impossible, unfortunately. iGlasses can lock the exposure, but this only works in programs it knows about, which rules out most computer vision applications (e.g. Max/MSP).

It's a real shame, as it limites the use of the camera for CV applications.

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It may not help exactly, but Macam allows you to disable auto adjustment of gain and shutter (which is probably what you want) for many cameras. Using the svn version this work with the ps3eye (while the stock macam doesn't allow you to disable auto adjustment). Unfortunately, Macam doesn't support the iSight as far as I can tell.

(I'm adding this in case other people are also looking for a solution, who might not be bound to the iSight, and it's not obvious that using the SVN version helps)

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Just wanted to add that I've managed to get control of this camera and Logitech c920 in c++ using openframeworks and ofxUVC which is a wrapper for the Linux UVC library

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It's not clear whether by "adjusting the light/focus" you're referring to the resulting movie or whether you're referring to the effect of the light sensor (next to the camera) dimming of the monitor/screen?

If it's the first then this seems strange - are you wanting to keep images under or over exposed? Someone else will need to help you on this... and it probably is either buy something commercial or include the phrase "open source" in your web search.

The second... you'll find in system preferences "Displays" and at the bottom there (easy to miss) a tick box labeled "Automatically adjust display brightness as ambient light changes". Un tick the box and you are master of the brightness of your screen.

Hope that's helpful.

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No, I think he's looking to turn off like auto focus, and stuff like that. – Brian Postow May 20 '10 at 20:07

The Answer is Simple: just go to Display settings and uncheck "automatically adjust brightness as ambient changes.

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Not that he'll ever see this, but that's the screen brightness. It doesn't have anything to do with the camera's auto-exposure. – Glenn Maynard Jan 13 '15 at 19:47

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