Question: Lego Spectrometer suitable for studying sunlight?

jsbonillam is asking a question about spectrometry: Subscribe to answer questions on this topic

jsbonillam asked on January 05, 2018 19:53
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4 Comments

warren 3 months ago

How would you set up the spectrometer next to the other equipment, or the tracker? Are you using a raspberry pi camera as-is, as well, or just as part of a spectrometer?

jsbonillam 3 months ago

@warren The camera will be just part of the spectrometer. I am still considering whether to use LDRs (light depending resistors), as here http://www.instructables.com/id/Arduino-Solar-Tracker/ or using Pysolar which calculates the Sun's predited position according to your coordinates http://pysolar.org/ . I personally like more the first one but both of them seem fine. Just tell me if you think one of them is better.

warren 3 months ago

Oh, i don't know, but it looks very cool!

Metamer 2 months ago

I, too am trying to get spectral data of sun/sunsets. Would be interested to hear what you've learned

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5 Answers

I think the Lego spectrometer's suitability for this is an open question, but the Raspberry Pi Camera v2 is very low noise and could be worth testing this idea out with. Please post your results if you do!


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Please forgive the question, but what lines are you using and what method of analysis? Thank you for the information.


jsbonillam 3 months ago

I am going to make and analyse the graphs with the wavelength and absorption.

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Only one suggestion then. Sunlight can be strong. As a safety measure, partially block the sun and work your way up to full exposure. Might not be needed, but better safe than sorry.


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I have used photographic neutral density filters and have not been able to view the sun directly using the spec3 highly modified device. The attenuation ranged from 2-400 and have added additional attenuation resultong in overexposed images. Do a search of my previous spectra. I have built many versions of the original. Stef


Ag8n 3 months ago

There are two approaches to this, the hardware and software. Sounds like you took care of the hardware end very well. Can you think of any software modifications or settings you could have changed?

stef 3 months ago

What I was alluding to is that with all of the filter attenuation, the cmos sensor was still overloaded. This can be seen in the spectra submitted by me and others. My opinion is that once the input (sun) is normalized, all of the software tricks can't help.

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Further to my previous replies, it may be possible to view the sun disk attenuated with the filters used by welders to view their work. I have not as yet tried this idea but do know that these filters are replaceable. Try harrbor freight or some other supply store for these filters. No guarantees that this will work for you, as it would require some form of spectral calibration to see what the response is.

Good luck with your project.

Stef


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