Sand Fluorescing Red

[Damon]

Here is the sand I was referring to awhile back. Plain ole sand in visible then goes crazy in UVIVFL. I am suspecting that since there are 4 species of fungus for every 1 species of plant--most of the world is probably coated in them. Although this specific red might be an algae. Perhaps I can soon get close enough to see it.

 

Sand in Visible LED light

 

 

Sand in UVIVFL

 

 

Diptych

[Andrea B.]

I really would like to know what causes the red fluorescence here.

If you dig down into this sand to look at some which is under the top layer, does it still fluoresce?

[baffe]

We have the red fl too. Everywhere where the stones are granite and wet. Sometimes on differet types of Stones too.

 

But never on the upper side where stones dry off completely.

 

I think this are bacteria or different microorganisms.

[Alex H]

Are you sure this is not the contamination that Shane was talking about?

[baffe]

A stone from outside, just behind our house. West which is called "the weather side" here. It was surrundet by some different stones looking equal but not showing this effect. And it had the effect only on the lower surface. Furter I had to keep it wet because the fl went when it dried off.

White flashlight:

http://up.picr.de/20247448qm.jpg

 

UV Led 1W 380nm noname, with a lot of contamination and with visible fl on background paper but not on "red spot":

 

http://up.picr.de/20247449hk.jpg

 

UV flash, visible fl on the stone but not on the "red spot":

 

http://up.picr.de/20247450fi.jpg

 

With MT301 365nm Nichia Led:

 

http://up.picr.de/20247451fa.jpg

 

In my opinion fl is dependent on:

-wavelength, extreme different quantum yield on different wavelength between 365nm (nichia) and about 380(nm). No fl on "blacklight" and flash at all.

-humidity, I always had to spray water onto the stone to get fl

 

Surprisingly the temperature of outside 0° C and inside 22°C had no big effect to fl except that of loosing humidity (and fl) quickly inside.

 

Pentax K-x, Kiron 105mm f2.8 macro, WB flash, no filter on cam and led

[JCDowdy]

Are you sure this is not the contamination that Shane was talking about?

 

I was wondering the same thing. Have you tried his suggestion of shooting a chromed bearing or something to see if the long wavelength leak of the Blackray is the source of this?

[baffe]

No I did not try his suggestion because I do not know what he was talking about. Can you please post me a link?

 

The red spot is only visible in 365nm Led light as I posted above. Not visible in blacklight and not with my uv flashes and even not in 380nm led.

 

Is "long wavelength" ir? Does the nichia produce ir? I do not know. My old spectroscope shows internal fl on 365nm and my new is not finished.

[Damon]

I will look into this today as well as put it under a stereoscope/microscope and look at it. I will try the ball bearing test too.

I do know these Blak-Rays pick up a lot of fluorescing things. Just moving the leaves away and I am likely to spot a handful of stuff fluorescing.

 

The red I posted awhile back on the underside of a large rock turned out to be a moss.

 

Anyway, I am going to look now.

 

-D

[Damon]

Ok so I did some testing. Forget the stereoscope and microscope. Neither helped me figure out the Red.

 

Andrea--Red color in sand is only a small layer on the surface--see below.

 

Wavelength Leak Test:

I used a small (~1/4") shiny chrome cap nut. It's a nut that has a shiny chrome dome for a top. I took pics of the nut on top of the red sand at the same time. Supposedly if I can see a magenta color from the Blak-Rays B-100AP on the chrome in my images, then this known light leak is getting to my sensors and thus possibly affecting the end result. The light leakage is at 405nm and 668nm according to member Shane. And he is really smart with these kinds of things so odds are that is the case.

​3 Blak-Rays were shined on the nut/sand simultaneously.

 

Results:

Canon 30D with MP-E 65mm macro = no visible long wavelength leak. Nut is practically black while sand is still red.

Canon SX50 = Slight reflection visible of Blak-Ray lights on surface of nut. Nut is practically black and sand is even more red

 

I also took some 5X close shots as well of just the sand. This is extremely fine/small sand but filters quickly. It is why the Pine Barrens of NJ recharges itself so quickly. There is a 17 trillion gallon aquifer under this area.

All pictures below straight out of cameras with zero editing.

 

 

Layer thicknes of Red Sand

UVIVFL: Canon SX50 Unmodified, 3 Blak-Rays B-100AP, 13 s @ f/8 ISO 80, No Filters.

 

 

5X close up of sand

Visible Light: Canon 30D Unmodified, Canon MP-E 65mm macro @5X, Halogen light, 1.3 s @ f/16 ISO 125, No Filters.

 

 

UVIVFL: Canon 30D Unmodified, Canon MP-E 65mm macro @5X, 3 Blak-Rays B-100AP, 30 s @ f/6.3 ISO 125, No Filters.

 

 

Diptych

 

 

UVIVFL: Canon 30D Unmodified, Canon MP-E 65mm macro @1X, 3 Blak-Rays B-100AP, 30 s @ f/14 ISO 200, No Filters.

 

@5X

 

 

Here is the camera that hows some of the Blak-Ray--and notice that the sand is also more red.

UVIVFL: Canon SX50 Unmodified, 3 Blak-Rays B-100AP, 4 s @ f/5 ISO 80, No Filters.

 

 

And finally some generic pics of the sand.

Visible light: Canon SX50 Unmodified, Halogen light, 1.3 s @ f/8 ISO 80, No Filters.

 

 

UVIVFL: Canon SX50 Unmodified, 3 Blak-Rays B-100AP, 5 s @ f/5 ISO 80, No Filters.

 

 

-D

[colinbm]

Really exciting Damon, the differences in the two Canons & the way they see the Blak-Ray lamps & fluoresence, great work.

I'll let the big boys & girls comment on leakages.

Col

[JCDowdy]

Damon,

 

Very interesting results!

 

Your cross section "Layer thicknes of Red Sand" photo seems to indicate the possibility of algal colonization of the upper layer to a depth where sufficient light might penetrate to support photosynthesis. However, the "UVIVFL: Canon SX50.." of the chromed nut clearly shows some reflectance of red leak imaging the source through the lamp filter. I interpret your results so far to suggest you may be seeing some of both a red UVIVF from algal chlorophyll and a red leak from the Blak-Ray filter.

 

If you could somehow place a BG type filter between the Blak-Ray and the sand and repeat the "UVIVFL: Canon SX50.." photo, you may be able to eliminate the effect of the leak. If with the BG filter you see the absence of reflectance on the bolt while retaining some of the red on the sand that would better support the presence of a chlorophyll signal in the sand.

 

Does clean bleached white sand, like you find at the hardware store, or if you clean the sand, does it still show this red UVIVFL? Either way it is a cool observation and a neat puzzle to solve!

[Damon]

Thanks guys, it's fun unraveling some of these mysteries.

 

I like the photosynthesis depth idea.

 

John--Doesn't the fact that with the Canon 30D and lens combo that shows no reflectance in the nut, but still shows the red, support the presence of chlorophyll concept?

 

I will think about the sand cleaning idea. I did look at it under some pretty high magnification with my microscope and still couldn't see anything with structure while under UVIVFL. Whatever it is--it's reaaallly small.

 

 

-D

[Damon]

BTW--I looked at sand only a few feet away from where I got this and it did not show any red. If I walk around with the Blak-Ray and look closely at the ground I see this red sand, but not everywhere...

Of course I did not take a any pics of that "no red" sand. :P

 

-D

[JCDowdy]

John--Doesn't the fact that with the Canon 30D and lens combo that shows no reflectance in the nut, but still shows the red, support the presence of chlorophyll concept?

Perhaps but it would be more definitive to show the red leak removed from the source with a filter.

 

I will think about the sand cleaning idea. I did look at it under some pretty high magnification with my microscope and still couldn't see anything with structure while under UVIVFL. Whatever it is--it's reaaallly small.

 

You might be able to extract the red FL material in the wash, put some of the red sand layer in a clean half full water bottle shake vigorously, and decant onto a coffee filter leaving sand behind in the bottle and red FL on the filter......

 

BTW--I looked at sand only a few feet away from where I got this and it did not show any red. If I walk around with the Blak-Ray and look closely at the ground I see this red sand, but not everywhere...

 

One might expect red FL algae, if that is what you have found, can only grow where conditions allow.

 

Alternatively, such a fiendish hue it may only persist where the Jersey Devil takes a leak....

[nfoto]

Cyanobacteria might be a possibility as well.

[Damon]

Baffe--thanks for trying that out. It helps that you jump right in and try some experimentation. Here is the link to the thread that contains the reference John & Alex were talking about--just scroll down a few posts.

http://www.ultraviol...5-uvivfl-setup/

 

BTW, when you used the MT301 365nm Nichia LED, did you have a filter in front of the light/camera? And how far away was the light from the stone? Do you like the light?

 

John--Re:Jersey Devil--that was the primary hypothesis I had, but I couldn't figure out how to replicate/prove the results, and wasn't sure how to approach this fine outstanding community with such a question...although then maybe we could draw out Bjørn to talk about the Norweigan trolls and other supposedly "mythical" creatures. :P

 

-D

[Damon]

John--is it safe to say I can use my Canon 30D setup and not worry about this light leakage affecting my images?

 

-D

[baffe]

I didn't use a filter not on the cam and not on the lamp.

 

The lamp was at a distance of about 25cm (10') away from the stone and I moved it around during exposure to avoid the sharp lightspot on the stone.

 

I'd like to have the beam of the MTE a little more wide and homogen. Mine has a bright inside spot and a darker outside ring.

 

The MTE301 placed on plywood with uv active coating:

http://up.picr.de/20259520kw.jpg

 

It's beam:

http://up.picr.de/20259521cd.jpg

 

Opposite a homemade USB powered uv lamp:

http://up.picr.de/20259523hj.jpg

 

Beam of homemade lamp:

http://up.picr.de/20259524qt.jpg

 

Homemade lamp. Made from heatsink of white LED lamp. I removed housing and electronics and put a uv led in and electronics to the back. The grid is not good, it's shadows are visible in the beam picture but it's necessary to keep reflector in place. Formerly this was done by a plastic cover in front of led. Possibly polycarbonate...

 

http://up.picr.de/20259525if.jpg

[Damon]

That seems like an awful lot of white light there in the beam of the MT301. If you are serious about using that light for FL work, may I suggest blocking that white light.

 

When shooting my little yellow flower recently under UVIVFL, I would occasionally pass my regular LED flashlight over it to help in focusing situations. Just the ambient LED light changed the color of the flower and it's parts. We are free to enjoy whatever colors we want of course, but most of it became less fluorescent or lost that property completely.

 

Love that USB powered UV lamp. how much power does that draw? What wavelength?

 

-D

[Damon]

Re: Cyanobacteria - neat idea.

If I can get my microscope going correctly, I should be able to see bacteria at 400X -1000X.

[baffe]

That only seems to be. This is because in that areas the sensor is overexposed. The blue value remains at 255 (8bits) and the others come up so resulting color changes to white. But of course there is some white light. I usually use UG11 to reduce that if necessary.

 

The homemade USB powered lamp shows much more white light. I bought (and payed) a 365nm 1W led but it is not. Is something round 380nm. But the value is not reliable because my spectroscope shows internal fl at uv (I'm working on that).

 

The "highly sophisticated electronics" is a simple resistor limiting the led current to 370mA (nominal value) and a on/off switch. At a voltage of 5VDC from usb a possible solution.

[JCDowdy]

John--is it safe to say I can use my Canon 30D setup and not worry about this light leakage affecting my images?

 

The 30D at least seems your better choice of the two from what you have shown. However, standard practice is of course to remove as much Vis & NIR from the excitation source as possible while blocking same from the sensor. These inspection lamps you have are used primarily for leak detection with fluorescent tracer dyes so presumably the secondary bandpass of the filter must not interfere significantly with that function. I think you have demonstrated that this secondary bandpass is falling within the camera Vis/NIR sensitivity. Your photographic work looks great as is, but these wavelengths could be further attenuated if you want, if you can find a suitable large filter.