Extra-virgin Olive Oil Fluorescence

[Andrea B.]

So it seems that extra-virgin olive oil made from young green olives contains enough chlorophyll to fluoresce under UV light.

 

References:

• Analysis of Olive Oils by Fluorescence Spectroscopy
  
• Fluorescence of vegetable oils: olive oils.
  
• Fluorescence spectra measurement of olive oil and other vegetable oils.
  

 

Equipment:

Olive Oil: Trader Joe's Extra Virgin California Estate Olive Oil. Unfiltered and cold-pressed from arbequina olives.

Container: Pyrex glass dish.

Background: White foamboard.

Camera: Nikon D600-broadband.

Lens: Coastal Optics 60/4.0

Filters: See below.

Location: Dark coat closet.

 

 

UV-Induced Visible Fluorescence :: Yes

Illumination: Nichia 365 nm UV-Led

Excitation Filter: U-360 (2.00mm) + S8612 (2.00mm)

Lens Filters:

• Baader UVIR-Cut
  
• Baader UVIR-Cut + 695nm Longpass
  The purpose of adding the longpass filter was to trap the response around 700nm (approximately).
  

While shooting this set, I tweaked Nikon Picture Control and White Balance settings until I got very close to what I was actually seeing.

 

 

 

I did not mean to use f/11 for this shot, so this should probably be redone.

The equivalent exposure is f/4 for 4" @ ISO-200. It makes sense that this exposure would be longer than the preceding f/4 for 1/3" @ ISO-200 because I was shooting through 2mm of additional filtration here.

 

 

UV/Violet-Induced Visible Fluorescence :: Yes

Illumination: Nichia 385 nm UV-Led

Excitation Filter: StraightEdgeU

Lens Filter: Baader UVIR-Cut

 

 

 

UV/Violet-Induced Visible Fluorescence :: Yes

Illumination: Photon Micro-Light 405nm LED

Excitation Filter: None

Lens Filter: Baader UVIR-Cut

 

 

 

UV-Induced Infrared Fluorescence :: Yes

Illumination: Nichia 365 nm UV-Led

Excitation Filter: U-360 (2.00mm) + S8612 (2.00mm)

Lens Filters:

• RG9 IR-Bandpass Filter. Cuts in just before 700 nm.
  
• 780 nm Longpass (2.00mm). Cuts in around 750 nm.
  
• 830 nm Longpass (2.00mm). Cuts in around 800 nm.
  
• 780 + 830 Longpass Stack (4.00mm). Just to make sure that is really IR that I'm recording, I doubled up the Longpass filters.
  

The false colours in this set have not been standardized.

Please do not read too much into them, OK?

 

 

 

 

 

 

Cyan-Induced Infrared Fluorescence :: Maybe captured some Red + IR around 700nm?

Illumination: Micro Photon 495 nm LED

Excitation Filter: S8612-2 (2.00mm) with peak at approx. 490 nm

Lens Filters:

• 715 nm Longpass (2.00mm). Cuts in just before 700 nm.
  
• RG9 IR-Bandpass. Cuts in just before 700 nm.
  
• 780 nm Longpass (2.00mm). Cuts in around 750 nm.
  
• B+W 093. Like an 830 Longpass.
  

I have not attempted to standardize the false colours in this set. Please do not read too much into them.

 

Again I made the f/11 aperture setting in error in this set (because I forgot to over-ride a memory bank setting).

I might have captured more of the weak response if the lens has been wide-open at f/4.

So the cyan-induction experiment definitely needs a reshoot.

 

 

 

 

[Andrea B.]

Addendum:

In the preceding work, I filtered my Nichia 365nm UV-LED with a U-360 + S8612 stack to cut as much visible light output as possible. And, just in case, to also cut any IR. But I don't think there could possibly be any IR output from a UV-LED.

The Baader UVIR-Cut filter on the lens passes light around 400nm, but I don't know how much is below 400nm.

 

With this light filtration and lens filtration, there is some apparent violet leakage around 400nm. To show this I made some shots of a Spectralon square leaning against some white foamboard. The colour seen in the top half of this photo on the Spectralon is somewhat close to the violet which I was seeing while shooting.

 

But it seems impossible to accurately reproduce the colour of spectral violet. It is much more intense than what is seen in the top half of this photo. I can only see spectral violet with my repaired, cataract-free left eye which has the artificial lens implant. I cannot see it with my right eye which still has its original lens - now become yellowed with middle age as happens to most of us. I think of spectral violet as a deep, intense red-violet wine colour but it is not a dark magenta at all. It dances in the eye, like you can feel its vibration.

 

Our friends, the Lint Bunnies, hopped into the photo as always. Bunnies is too nice a name for them. They are more like Lint Lice, yuk.