Has anyone tried a long wave UV LED flashlight? I thought I might get one and try finding some fluorescent rocks if they are any good. I see you can get them for about $20 on Ebay. Is there anything in particular I should look for before I buy?
I have several of these. I wouldn't pay $20 for one as small keychain ones can be had for $5 and ones that clip onto the brim of a baseball cap for about $8 (they sell them at Walmart, for instance, for fishermen so they can see fluorescent lures and line while night fishing). Realize that often these do not emit the same wavelengths as traditional longwave UV or blacklights. For many minerals that are longwave active, the effect is minimal with the UV flashlights. However, rubies are much more reactive under them than with traditional blacklight in my experience.
In my opinion the shorter the long wavelength the better,(confused yet?). Meaning since 400nm is the far end of visible light (blue) you should try to get a LW LED that outputs its peak at less than that. I like the peak to be at most 380nm and 365nm is best. Of course you pay more for the lower nm ones. The reason for the lower wavelength is that it gives the material a bit more energy and as a plus you can hardly see any light coming out from the flashlight. I took it a step further and bought at dichoric UV bandpass filter to put on my LW LED flashlight that blocks all light but a narrow band from 365nm-385nm. You can really go crazy with the UV lighting for Fluorescent mineral hobby. The shortwave stuff will really get you in the wallet. I kinda depends on what you are willing to pay. I relate it to buying a telescope, you always need a more powerful more expensive one. You can get a good 49LED LW flashlight for about $40 and an OK one for about $25.
Great post !I was wondering about these LED's too. I think it will be fun to try night rock hunting on the huge piles of sorted river rock/gravel at our area gravel pit. Maybe I will find a diamond on the sand pile
Post by pcktfullofokenite on Jan 18, 2008 15:51:17 GMT -5
I have UV LED maglight and from what I've seen only certain fluorescent minerals will light up with it. Bluesman is right about the light wavelength being different, it's somewhere in the low end of the long UV spectrum with a lot of blue in it. I have some calcite from Mexico that lights up green and then phosphoresces with the light. If you really want a UV lamp for minerals, there are small portable types that are reasonably priced and not much more than the LED type, just look on EBAY.
I fling thy crummy rock from my hand and thus it leaves craters in passing road signs.
I would not waste money on LED UV Light. I have tried it and they barely work on the brightest of long wave minerals. Get a couple of these instead: www.goldmine-elec-products.com/prodinfo.asp?number=G9589 It works really well for long wave and is very cheep priced. Easy to modify to stay on past the skin safety limits. And it works on 12 volts so you can cut the cord and work it off a battery.
Add a new $4 mercury vapor tube and a short wave filter glass and then you have a short wave light.
By barely work do you mean if I went out at night and walked around with it I would see nothing? Or do you mean things would be very dim? I was thinking it the flashlights looked really convenient, if they work just for looking for rocks. The link you gave me looks perfect for the case I am planning to be able to display rocks in and a great price. Thanks.
There are alot of minerals that only fluoresce under Short Wave 254nm UV light. The LED technology has only just recently been able to produce these and they are big $.
My 49 Led UV Long wave light may not be as powerful as some other kinds of lights but it does make the LW minerals glow pretty bright.
Last time I was at the Crabtree mine I found some UV minerals from about 20ft away, just shining my light into the tailings.
Koolaid may be talking about the 9 LED light like they use in CSI.
I am making a 100LED LW UV light for field work that so far in testing really puts out the light.
Also it is worth noting that there is a variety of light outputs that you can get from LEDs. Try to stay with the higher numbers 8000mcd to 20,000mcd. Once again the cost scales up with the light output.
In the example below of hyalite from Spruce Pine the left picture is taken with the Long Wave light in the link mentioned in the above post and the right picture is the same rock using a Long Wave UV LED flashlight and the fluorescence is barely visible. I have found that the flashlights are almost useless for rock collecting. Of course Short Wave light has more minerals that will react to it than Long Wave.
If you wanted to turn a long wave light or any type 4 watt fluorescent light into a short wave light here are a couple of links. I have made over a dozen for different folks using the materials below. The pictures in the "Glowhound" section that I have posted were taken using a 4 watt home made light.
As long as you don't look into the light you should be fine. Here is a link to modify the Avon Skin light to stay on. It was designed to turn off after a minute so you would not burn your skin. If you get one with the other type board in it then PM me for the fix. I cut the cord on some of mine and attached lugs on wires so I could attach the feed wire from the light to a small 12 volt rechargeable battery kept in a nail apron to make a good portable light. I have glued the glass lens directly onto the front of the Avon light with black silicon caulking. I even made on with 2 bulbs in it instead of the one. Let us know how it works if you build your own.
I bought a handheld flourecent today and I have Koolaid's link bookmarked so I can put one in my case if I find anything good. I'm still a little nervous about the short wave, it sounds a bit dangerous. But thanks for all the info.
Well I just got my light. ;D I've been testing all my rocks to see what glows. Maybe 5% of my stuff glows some fairly bright! Well I'm hooked now. I just ordered koolaid's light, the little one I have will be great for a pocket and now I'll have a big one for my case and to look with. Thanks for all the help. Scott
I just got two of the Avon lights. I downloaded two differnt mods to bypass the 1min turn off. I will post a photo tutorial on modifying the lights to bypass the turn off using a combination of the mods I found. I had to add a switch as the mod disables the switch on the light. I plan on having one LW and one SW for the field after I finish the mods. Thanks again koolaid for the info. bammer
Just installed the SW 254nm lamp in one of my Avon lights I modified. Works great but I have determined I need the bandpass filter in order to screen out the visable light that floods out the UV light. Oh well another $40 or so should do the trick.
With the great Franklin New Jersey Trip Report I thought there may be a renewed interest in the UV lights.
So far I have: - Made two AVON light conversions(bypass the 1 min turnoff) and purchased a SW bulb for one of them. I also made them battery powered. - I purchased a floor model SW UVC-26,6 watt,254nm that retails for $285.00. It is a field light that has two 6w SW bulbs and a SW filter.(cost me $100) - Created from new parts a 36w SW battery powered field light light that uses the filter from my UVC-26 SW light.
If anyone is interested in creating one of the AVON lights or a larger 36W light let me know as I have all the info that I used to do it.
The 36W sw light cost me about $100 in parts plus the $100 I paid for the floor model SW light. You say $200 for a UV light! I say go look up the price for a battery powered 36W SW light and then you will realize I made about a $500 retail light.
This UV hobby is really neat I am glad that I had the patience to get a SW light that really puts out the light.
My collection grows every time I go out with my light. It is amazing how many boring looking rocks really light up with the UV lights. Flowers at night can really suprise you also.
I have two of these lights and they work fine for looking at your UV minerals. They are a bit weak when using them in the field.(only 6W).
If you use the SW bulb you will need a SW bandpass filter.
I have a larger 36W SW battery operated field light that I build from parts if anyone is interested I will make available the parts list and instructions. (this 36W light is definitely adequate for field collecting)
This is like the one I had at Magma Roundup... It is cool, works nice for a LONGWAVE... (I think after a few beers, I said shortwave once, but it was longwave incase I confused anyone.)
I think the range was 395 or so... I saw a new one this year that was down to 380, but this is still the low end of the longwave spectrum.
Shortwave will give you more pretty, but I don't believe you will find ANY shortwave L.E.D.'s yet...
The nice thing about the L.E.D's are the portability and sleek design...
I look forward to building some of the Avon mod lights, soo thanks for the Posts Bammer...
BTW, recent MWF conference and show had a converted trailer in the show that when you went in, shut the door, turned on the UV lights, you had a wonderful UV display.... Just something to think about for those that have Rock Club show's to work on...
I'd rather have a bottle in front of me than a frontal lobotomy
Update on the 36 watt home made 12v battery powered SW UV light. It works well and after I painted it, it looks downright acceptable. (medium size cat used for scale)
I used a filter from a smaller light I purchased.(see previous posts for details)
Still haven't spent much time in figuring out how to photograph the UV minerals. I started with the NJ minerals as they produce the most light.
This is a good field light, my first SW light I had to basically crawl on the ground and hold the light inches from the ground to see any flourescent effect. At least with this light I can walk around normal like, of course the trade off is having to carry an external battery. I just put a lawnmower battery(weighs in at about 10lbs) in my backpack an this gives me plenty of available juice that lasts for hours.
Dicky the Rockhunter, Probably not, most anything labeled long wave only puts out light in wavelengths down to about 350nm, so even if you filter it with a SW filter you would not see any light getting thru the filter at all. I have a dichoric filter that looks like a mirror that I use on my Longwave LED flashlight that helps narrow the band of light, but I don't think they make these for SW. Polarizing the light would just be lining up the wavelengths and would just make the light seem dimmer. You basically would be making the light go thru a Venetian blind so it blocks some and makes the light that does go thru 'coherent'.(lined up)
If I may throw out some info: The LED lights are unique in that they can generate very narrow bandwiths of light. The SW LEDs are still experimental. The shortwave Fluorescent bulbs put out alot of shortwave light but they also put out some visible light. This extra light usually is enough to wash out the fluorescent effect of the mineral you are looking at. That is why they use a bandpass filter for shortwave lights. The filter only lets a narrow band of light pass thru it, like 200nm to 300nm and its peak transmission should be right at 254nm. Because of the technology and process used to create this 'black glass' it is usually expensive. That is what was stopping me from building my light. It was too hard for me to pay $200+ for a 2" x 6" piece of glass.(until I found a deal, see past posts)
So this brings us to the 'bump in the road' that most of us glowhounds have had to deal with, the reality that to see the really cool stuff you need a SW light, and to get a SW light of any decent quality you need some real money. Oh and also the sad fact that the SW filters degrade over time so buying a used SW light has a risk of having a solarized(foggy) filter depending on how much it was used.
400nm is where deep blue visible light starts. 375nm - 395nm is generally agreed on as Longwave 300nm - 375nm is generally agreed on as Midwave and probably dangerous to look at. 254nm is generally agreed on as Shortwave and dangerous to look at. Any lower than 254nm and you start to get ozone and that is dangerous to breathe and the light is super dangerous to look at.
Hope this helps, but I mostly hope it doesn't discourage you at all, stick with it, as opportunities show up once and a while. I had collected dozens of SW minerals before I could even see what they looked like with my own light.
It has taken a while but I achieved a goal by taking these pictures. I had to build a SW UV Light (see above posts) so I could take decent photos. Alot of experimenting with the camera. I made a separate link as the images take a while to load as they are animations from White light to SW UV light.
My light: 70W parts total = $180 filter = $120 total = $300
35W parts total = $90 filter = $120 total = $210
And, ...oh yes the 35W puts out the light, no more crawling on the ground holding my 12W SW UV light looking for glow rocks.
Can't wait till the 70W is done, road cuts should light up from the car.
It has taken me about two years to figure out the sourcing for these materials and I am willing to share the exact parts list, secret filter source and detailed instructions on assembly to anyone who is interested. Just PM me...I may ask for a trade for some minerals or glowrocks if you are willing otherwise it will be available for free.
If you have spent any time looking for plans on the net or cheap SW UV lights then you know the frustration I've had, thats why I built my own from simple materials. This light is robust, has a cooling fan and performs well in the field.
Now its time to get some glowrocks. Anyone intersted?