Problems with white balance

[unwohlpol]

Hi.

I've recently finished my rasperry-outdoor-weather-observation-camera an I'm quiet happy with it. There's just one major problem that's annoying: White Balance drifts into yellow as soon as clouds appear. Most of the time it's acceptable though... when there's sunny weather.

Is there a way to get better results? Are there plans to improve raspistill concerning this point?

That's the command I use:

Code: Select all

raspistill -t 30000 -o out_temp1.jpg -w 2048 -h 1536

So I don't mess around with manual WB; if I should I'd be glad if someone could give me some hints.

BTW: Here's an example of shot where the WB is way off:
http://666kb.com/i/cg7kip4f327974crx.jpg

It's better on this one:
http://666kb.com/i/cg7kog8vyzo5goujx.jpg

And this would be perfect:
http://666kb.com/i/cg7kp39rbuyqeiffx.jpg

[lingon]

I agree that the white balance produces "yellowish" colors of outdoor scenes in cloudy lighting conditions. It would be very nice if this could be improved on.

[poing]

Well, in theory adding '-awb sun' to the command should always give you the same white balance. Note that it will give a blueish result on cloudy days.

You should also make a lens hood to prevent the sun hitting the lens.

[unwohlpol]

Well, in theory adding '-awb sun' to the command should always give you the same white balance. Note that it will give a blueish result on cloudy days.

You should also make a lens hood to prevent the sun hitting the lens.

Thanks... but as you already stated: I don't want blueish colours either. Nowadays almost every cheap compact camera can handle WB in outdoor condition (indoor/artificial light is still a problem though) - so I guess it can't be a miracle to make the camera board work here too.

I was also thinking about a Workaround: If it would be possible to define a specific spot on the image area where the camera measures the WB, I could place a graycard (or something the like) somewhere on the borders of the image area so the camera should not be distracted by clouds and stuff.

But: Is there a possibility to change the WB measurement area?

@Lenshood: Later maybe... for the first test shots I don't mind the flares.

...

But at the moment my major problem is of a different kind: The camera board refuses to work. For seemingly no reason... not even the LED on the board flashes on startup.

I agree that the white balance produces "yellowish" colors of outdoor scenes in cloudy lighting conditions. It would be very nice if this could be improved on.

Thanks for confirmation.

[jamesh]

It's a tuning problem - this sensor hasn't had a huge amount of it, but we have no-one to sort it out at the moment. I'll see if a guy who recently did some work on another sensor Omnivision sensor that was also relevant to ours might be able to shed some light...

Edit: I should add this is a GPU problem, and nothing to do with raspistill itself.

[unwohlpol]

It's a tuning problem - this sensor hasn't had a huge amount of it, but we have no-one to sort it out at the moment. I'll see if a guy who recently did some work on another sensor Omnivision sensor that was also relevant to ours might be able to shed some light...

Edit: I should add this is a GPU problem, and nothing to do with raspistill itself.

Thanks for the info.

[poing]

I was also thinking about a Workaround: If it would be possible to define a specific spot on the image area where the camera measures the WB, I could place a graycard (or something the like) somewhere on the borders of the image area so the camera should not be distracted by clouds and stuff.

I'd do that with imagemagick.