Excellent but Hot uv light

[dabateman]

I recently purchased the following light from Amazon for $30:

 

Lucky herb Reptile UVA UVB Mercury Vapor Bulb Lamp,Screw Thread,125 Watt

 

It has clear front glass and is a self ballast mercury vapour lamp. You can screw it into a standard light fixture. It gets quite hot infront and I would not recommend it for people.

Using it at a range of 2 feet from the subject, I was getting great exposure value using my 313bp25 and 340bp10 filters. It does output IR, but this can easily be monitored.

With my recent converted Em1 for middle histogram and the 313bp25 filter stacked with the 330WB80 improved filter, I had exposure of 3200 ISO, f5.6 and 10 seconds. With the 340bp10 filter stacked with the Baader venus, I had exposure value 3200 ISO, f5.6 and 2 secons for a middle histogram. These stacks completely eliminate IR leakage.

 

However, when trying to get a white balance for 10 seconds, I wasn't wearing gloves and my thumb did get a tan. So this light should be used with googles and gloves! I am pasty white so your tanning milage will vary.

[Andy Perrin]

Anything that tans your thumb in 10 seconds is in the “very dangerous” category as far as I’m concerned! You may wish to enclose it in a box or something?

[Cadmium]

Dabateman, Got a link?

[JMC]

If you got a tan in 10s from it, that is a huge safety issue. More data or as Steve says a link to it would be good. Got a Solarmeter? If so it would be interesting to see what it is actually producing.

[dabateman]

Cadmium, the exact one is gone!, this used to be the link, made in china:

https://www.amazon.com/gp/aw/d/B01MYO6EOV?psc=1&ref=yo_pop_mb_pd_title

 

I just tested the link and it only goes to the Coated one. You will want the clear one to get maximum UV. Amazon still seems to have the 100W one clear though. My clear 125W one has rating of 700uW/cm2 of UVB. This coated one is rated at 60uW/cm2 UVB.

 

Yes, little crazy, but First off I burn fast outside. Go from white to Red. So usually always have to wear sunscreen. The time was fast, but may have been 30 seconds as I held the Pfte block for full 10seconds exposure plus dark frame. Then when it failed I did again for 10 seconds and realized what I was doing and pulled my hand away. Its a slight tan not a burn.

 

Once when cutting DNA from a gel box my gloves were just not long enough to my coat sleeves, and I burned my wrists Red. That was fun, also a short exposure time but It was 254nm light that time.

[dabateman]

Just found this one on Amazon:

https://www.amazon.com/gp/aw/d/B0725RNDF2/ref=mp_s_a_1_5?ie=UTF8&qid=1537009310&sr=8-5&keywords=lucky+herp+clear&dpPl=1&dpID=51xXd97zqZL&ref=plSrch

 

At 160W and rating of 1560uW/cm2 UVB and cheaper at $28. That would be great, but probably really hot.

I buit a special holder and lamp base for mine to direct all light to subject area. My base can support upto 600W, So I may also try this one. But not on my skin.

[Cadmium]

Your bulb seems similar to the Exo Terra Solar Glow bulbs. They have some little graphs shown for those.

http://www.exo-terra.com/en/products/solar_glo.php

 

I have one of their CF Reptile UVB200 bulbs. Not the same, but...

http://www.exo-terra...tile_uvb200.php

 

More of their lights:

http://www.exo-terra...ts/lighting.php

 

Their Sunray bulb graph looks pretty good for UVB, I don't know.

http://www.exo-terra...sunray_bulb.php

[dabateman]

Cadmium,

Those all look way too safe. The spectra for yours looks good but the uvb output is very low. I would assume the glass is froasted or coated and not clear. Its really a trade between heat, uvb and safety. I am not a big fan of the heat, as it hurts the flowers I try to image. But may work for others, I think you will get less uv and more heat with the coatings.

 

I did order the 160W after posting. I also ordered a crazy 280bp10 filter which is well blocked into IR. I am curious now if I can push this to see if I can see anything. I remembered Andrea's 293bp15 filter that she was using outside. With this light and the Em1 able to do bulb mode up to 3 hours, I am curious how low the visual limit will be.

Theoretically, I think the Sony sensors are limited to 200nm, when naked. Mine still has the colour layer, the microlenses, the coverglass and then thick quartz block. So I may or may not be able to see at 285nm. I expect everything to be black there anyway, as all the tyrosine and tryptophan contaning proteins will be absorbing there. At 230nm everything is absorbing.

[dabateman]

Thinking about it, it would be really cool if I could filter the light using the 280bp10 filter and look at Tryptophan fluorescence using my 340bp10 filter.

Might just melt the 280nm filter though, as the mercury vapour lams get hot. I would have to add some cooling system.

 

But uv glow could be a new thing.

[Cadmium]

Have you been able to hunt down a graph from your bulb?

 

Regardless of your '10s thumb tan', I doubt you are getting as much UVB from the bulb as you may think.

You can and will get a tan or sunburn from unprotected arch welding,

that is why every inch of the body is covered with something dense, impervious to intense UV light, often with leather, and a complete face shield, usually containing a #12 to #14 filter.

However, not even arch welding will give you a tan that fast, or any bulb I know of. So I am not sure what to think about your tan, frankly it makes no sense to me.

I don't think you would be able to compare unless you had both bulbs, however, I am guessing your bulbs are essentially the same as the Exo Terra Solar Glow bulbs.

http://www.exo-terra...s/solar_glo.php

Their graph for that bulb shows very little UVB, but as with their UVB linear bulbs with which they show a separate graph for the UVB because the output is too low to show up well on the overall graph,

the Solar Glow UVB output is most likely similar in that sense.

http://www.exo-terra...b200-linear.php

 

No matter what bulb, always use precautions.

Arch welders cover every inch of their bodies because it emits extremely strong broadband UV.

 

Buckle up!

[dabateman]

Cadmium,

I don't own a Spectrometer. And I know how much you trust the Chinese spectra plots, especially the Zwb series. So below is a snap shot from the box, of what it claims the light out put is:

 

 

Below are the test images:

Lucky Herp bulb, EM1 converted with quartz, without dust shaker. Penatax UAT 85mm at F5.6 all ISO 3200, as I wasn't expecting anything to come out with my 313bp25 filter.

 

313bp25 filter stacked with 330WB80 improved filter 10 seconds:

 

These ones I like:

 

340bp10 filter only 2 Seconds, You can see the hint of IR in the photo, I like the accent.

 

340bp10 filter stacked with Badder Venus U, 2 seconds:

 

The 313 filter is in an even darker green point for the sensor. I see the same colors as Cadmium, with blue in the 380 to 400, Yellow in the 360 to 380nm and Green below 350nm, I am guessing based on on the curves that Johnathan has posted, that the blue dye drops off hard around 360nm, Then Red dye may also drop off around 350nm and Green takes over below 350nm. Not sure the limits. When I get the 280bp10 filter, I will see if anything shows up. Would be cool if Red makes a reappearance or it might just be dark green or black with no signal.