Do halogen blacklights even exist?

[Fandyus]

We all know about the oldest brute force technique for getting somewhat pure UV output, an incandescent bulb made of woods glass. What baffles me is that no matter where I look, all the bulbs made this way are regular incandescent bulbs, I never see a bulb made this way that would have the smaller quartz bulb inside. This is sort of frustrating because I have a halogen spotlight which is very good for mimicking sunlight in my multispectral photos, even being good enough for UVA without significant leaks.

While I do know that having such a bulb would not be good for any practical purposes, I'd still love to have one for collection reasons, they don't seem to exist though.

[photoni]

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[Fandyus]

@photoni Of course, these are nice, but I was talking about ones encased in woods glass to help attenuate the visible and some of the IR.

Edit: Actually, I re-read your comment and realized you might have said something different. Do you have these, but inside woods glass bulbs? If so can you please post a photo? I'd love to see.

 

 

[photoni]

@Fandyus hahaha google translate fooled me wood is not lumber but Mr. Wood black glass.
I've never tried these lights but I've tried the fluorescent type which is around 350>400nm, but it's only 25W very little usable

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I've seen some for sale on Ebay, if you can't find them, use a quartz light like the one I showed you with a ZWB2 filter in front

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I believe that the production of these incandescent wood lights and also the fluorescent ones is prohibited (with Hg) , the sale of stock funds is allowed.

[photoni]

www.ebay.it/itm/302111872746

 

[Stefano]

I once tried to temporarily attach a UV bandpass filter stack (colored glass) on the front of a halogen spotlight, the round ones with a reflector. The reflector and the filters seemed to have the same diameter, I think 50 mm. The lamp was a 12 V 50 W one, I think. It worked, paper and highlighters glowed, but after 1-2 minutes of operation the filters were way too hot to touch.

[dabateman]

I have never seen a halogen based black light.

My guess for why not, is that halogen lights output a lot more other wavelengths above the 400nm cutoff, than incandescent bulbs.  Placing a filter to block those other strong wavelengths will result in a lot of heat. My guess is they are just too much of a fire risk.  Incandescent black lights are also a fire risk on their own and care must be taken with their usage.

I quickly switched to Mercury based bulbs, as much cooler. Black coiled fluorescent bulbs are just better. 

[ulf]

1 hour ago, Stefano said:

I once tried to temporarily attach a UV bandpass filter stack (colored glass) on the front of a halogen spotlight, the round ones with a reflector. The reflector and the filters seemed to have the same diameter, I think 50 mm. The lamp was a 12 V 50 W one, I think. It worked, paper and highlighters glowed, but after 1-2 minutes of operation the filters were way too hot to touch.

That is the same problem you get with high power LED arrays, even if the optical power emitted is passed to some degree.

There is always some absorption that is converting optical energy to thermal energy in an ionic filter.

[photoni]

on this site they are more specific  LINK

Suitable for 400w UV cannons and floods.
400W high pressure UV lamp with E40 fitting.

Once the bulb(s) has been switched on, it should take approx. 10mins before reaching full capacity. This is due to the bulbs containing a ballast which releases the gas slowly.
Specifications :  Power supply: 230Vac, 50Hz
Lamp fitting: E40
Rating: 400W
Wavelength: 365nm

 

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These with standard E27 socket I think are normal incandescent lamps with a black glass that lets through blue light and UV 400 nm ... and more IR :-) 

LINK

 

[Fandyus]

13 hours ago, Stefano said:

I once tried to temporarily attach a UV bandpass filter stack (colored glass) on the front of a halogen spotlight, the round ones with a reflector. The reflector and the filters seemed to have the same diameter, I think 50 mm. The lamp was a 12 V 50 W one, I think. It worked, paper and highlighters glowed, but after 1-2 minutes of operation the filters were way too hot to touch.

You are a brave man, I thought of trying that and then I immediately dismissed it at the fear of either A) the filter gets badly damaged due to thermal stress or B) the filter starts reacting with air as it heats up and produces toxic fumes. Safe to say, I don't want to have to deal with either.