[libcamera-devel] [RFC 7/7] libcamera: sensor: ov5670: Add lens properties

[Jacopo Mondi]

Hi Andrey,

   I premit I don't have a manual for the sensor nor the optical
   specification, so I referred to the ChromeOS BSP to retrieve this
   information. All the values here are copied from there.

On Wed, Dec 18, 2019 at 10:41:59PM +0300, Andrey Konovalov wrote:
> Hi Jacopo,
>
> On 18.12.2019 17:50, Jacopo Mondi wrote:
> > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> > ---
> >   src/libcamera/sensor/ov5670.cpp | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/src/libcamera/sensor/ov5670.cpp b/src/libcamera/sensor/ov5670.cpp
> > index c2d996785717..a25bfd246f8b 100644
> > --- a/src/libcamera/sensor/ov5670.cpp
> > +++ b/src/libcamera/sensor/ov5670.cpp
> > @@ -30,6 +30,12 @@ int OV5670CameraSensor::initProperties(const ControlInfoMap &controlMap)
> >   	properties_.set(properties::BayerFilterArrangement, bayerFilter);
> >   	properties_.set(properties::ISOSensitivityRange, { 50, 800 });
> > +	/* Lens Properties. */
> > +	properties_.set(properties::LensApertures, 0.0f);
>
> What is the meaning of the aperture of zero?
>
> > +	properties_.set(properties::LensFocalDistance, 3.69f);
>
> This means that the lens has the focal length of 3.69 mm, correct?
>

very short right ? Can't tell if it's plausible or not though

> > +	properties_.set(properties::LensHyperfocalDistance, 0.0f);
>
> Same question as for the aperture above (zero value for the property which is essentially non-zero)
>
> > +	properties_.set(properties::LensMinimumFocalDistance, 3.69f);
>
> Why is it the same as the focal length?
> If this is "The shortest distance in millimeters from the lens surface in which an
> object could be brought into sharp focus", then setting it to 3.69 is most probably
> wrong...
>

Probably, but as I've said those values come from the ChromeOS BSP and
I think they're overridden by the binary 3A implementation for the
platform where the sensor is installed on. Honestly, I am not sure
how to retrieve those values from if not from there...

Thanks for you feedback
    j


>
> Thanks,
> Andrey
>
> > +
> >   	return CameraSensor::initProperties(controlMap);
> >   }
> >
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