Sorry if my simple description from the first post was misleading. A as good as I can manage with the RGBW sources is good enough for me.
@cdev: No worries about looking direct into the LEDs. It's behind my bed and cowered with a opaque diffusor.
Wrt different sunrises at different locations. That's actually one additional plus for the sensor: It's easy movable and I can ask someone who travels at a nice place to do the recording.
Yes I could use my camera in HDR or do some additional calculation to compensate changes of the exposure time (I would keep the diaphragm fixed). But I feel that this is rather cumbersome setup; especially as my tripod is a heavy load (Manfrotto) and I don't own a car.
@rs20: About the usage of the white channel: Thanks for the heads up. It would be very obvious to get completely overblown rendering of the record. That needs to be taken care of. I noticed that extreme wide range of the W channel too. I think ill still record it and keep the data but not use it.
I think a mismatch of the Filters and the LED colour might be bad. Just imagine the red LED is shifted compared to the sensor that only 20% passes the filter the RGBW sensor: The reading will be much to low and you would think you need to beef up the R channel more than necessary.
I see the sensor like a small project. For both the Cam and the Sensor I need the hardware setup (opaque dome or reflector, ...) the calculation from the sensor/cam needs to be done. Here the sensor gains a bit as I have already the RAW data in a nice format. And I have several controllers flying around which are currently waiting to be used.
@BrianHG: Probably I'l use one sensor which is used for both usage models. As I don't plan to compensate changes on the room I do a single calibration run to identify correction curves that are applied to the RAW sensor data on a PC. the processor might have enough CPU power to do this online. But imagine something red falls on the sensor and you will wake up under a green-blue sky
The pinhole lens sound like a good idea! Worth a try.
@reen flash: (OK, that's not a user rather a topic) I've watched so many sunsets over the sea and never was lucky to see one. I was aware of this effect and hoped so many times.
To my understanding a place with a view over the sea will do. And the weather conditions must be perfect: The sky must be clear and the right temperature conditions over several air layers must help to bend the light a bit around the earth surface.
I'm not sure if a plane is helpful. So far I only saw pictures from it on sea level.
Just for your entertainment I've added two pictures of the driver (6+1 12bit PWM channel, the MOSFETs are bottom side mounted, controller not mounted) and the LED stripes loosely placed in the profile with the opaque cover.
Edit: Added Pictures