Spectroscope

[photoni]

 

LAST TEST

 

Sony A7 fs Soligor KA 35mm f3,5 - soft C1 - white balance on teflon ball

 

- Above a normal neon with warm light
- under a "black" neon - wood light
- germicidal light ... was closed in a double layer of aluminum,
only a 2x20 mm slit towards the steel pin
on only one minute with 300 nm protective goggles

a little ozone was produced ... then I opened the window

 - Led NEMO 365 nm (with ZWB2 cover)

this appears to have a broad wavelength, from 365 upwards.

 

I took some sharper photos again, and improved this photo.

Now lines 365 - 405 - 436 - 546 are clearly visible

They are not the same as the graph but we understand that the diffraction grating is not linear.

 

A thousand thanks
Antonio

 

P.S. I believe it is the last test ... I would have a sodium vapor street lamp (589 nm) but I forget it ...

 

 

[photoni]

 

 

can anyone confirm me these wavelengths?

please

 

Antonio

 

 

 

 

@ulf said

Could it not be possible for you to use two light sources, the Neon light to get calibration data and the flash for the measurement, without moving around the setup too much.

That is how I always do for wavelength critical measurements with my spectrometer.

First the reference lamp for calibration, and then a continuous light source for the measurement

An easy to see example of this peak shifting is to look at transmission by a UG11. 

Alone it has an UV-peak around 336nm, but in combination with a BG39 (2+2mm), the left slope of this filter shifts the resulting UV-peak to 364nm.

 

I found a way to put the lights in the same position while keeping the distance and focus of the Sony + Soligor steady

 

[ulf]

I think that the two last strips are not perfectly aligned for correct wavelengths.

That can be the result of switching light sources. Such a setup is very sensitive and variations are difficult to avoid.

 

I see the same effect, but to a much lesser degree in my proper spectrometer setup by just changing between optical fibres with different core diameter.

That is one reason for me to always recalibrate before sensitive measurements.

 

I base my guess on my knowledge of the transmission of ZWB1, the general sensitivity-loss for shorter wavelengths by image sensors and the typical false colour at 365nm.

The continuous spectrum part in the "WOOD" strip looks more correct and also has the Hg 365nm reference peak in the yellow false colour band.

The change to purple happens above 370nm. I also expect to see more illumination at the two last strips closer to 400nm.

In that region I estimate the two last strips to be misaligned to the left at least 10-15nm.

 

Naturally my estimations might be off, as there are many factors that interact here.

 

Still I am quite impressed with what you have achieved so far Tony.

Well done!

 

[photoni]

 

after a year I add this image, with unconventional filters for IR and near visible photography

 

.

 

 

[Nate]

Spectrum looks good Toni