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Cold Light unit.

Posted by Stephen Eglinton  
Stephen Eglinton May 24, 2012 05:26PM
Are you able to have 3 light guide goose necks from any cold light unit (giving 3 points of light), or do you need to search for a unit that provides this facility?
Most units that i have seen pictured show only 1, or 2 at best.

Mineralogical Research Company May 24, 2012 09:45PM
Hi Steve,

The most common fiber optic sources have one output port, but two port units are available. (see attachment) The goosenecks are only available with one or two light guides.

From my experience, single port sources, with single goosenecks, are easier to position from any angle. Also, having just checked our dealer catalogs, I see that two port sources are more expensive than two single port sources. Go figure....

eBay is a good source for used sources and goosenecks.

open | download - dual fo illuminator.jpg (14.2 KB)
Kelly Nash May 24, 2012 10:14PM
Googling around, I do see some rerferences to 3-branch goosenectk light guides, but saw nothing with a price or ordering info.
Mineralogical Research Company May 24, 2012 10:19PM
Yes, I was surprised to see some as well. Trying to position my dual goosenecks is a pain and three would be impossible for my applications.

Stephen Eglinton May 25, 2012 01:51AM
Tar for your help guys.

As i am looking to use the lighting for macro purposes (on specimens up to 5 cm), i was supposing i would require three points of light. Hence three goose necks. I can't see where one or even two would do the job on sizes this large.

I would not have thought this form of lighting would be so difficult to use Gene, as in "positioning". Especially when compared to Flash, which is what i am moving away from... just too difficult.

The German photo company Novoflex made a cold light unit ( called the Macolight Plus) with 3 light guides. I thought... "GREAT!", but it operated using flash, where as i am looking for constant lighting. Also, they have now discontinued it, so that's settled that.

Harald Schillhammer May 25, 2012 09:41AM
If money is not a problem:
I once had a look at this system. It combines permanent light for positioning and can be switched to a Xenon flash for actual photography.

I wrote to them for further information and never received a reply so I opted for something else - the sugarcube offered by EdmundOptics which is incredibly bright but unfortunately also uses only two-armed fibre optics.

Bart Cannon May 25, 2012 11:48AM
Go to IKEA..

They have a lovely 16 inch goose neck pure white LED illuminator.


I bought four of them.

Harald Schillhammer May 25, 2012 11:56AM
Bart Cannon Wrote:
> Go to IKEA..
> They have a lovely 16 inch goose neck pure white
> LED illuminator.
> I bought four of them.
> Bart

Same here :). These Jansjö LEDs are great - if you have a rather vibration free working environment. In addition, manual white balance is mandatory. Virtually all my micro images on mindat have been taken with those lamps. But once I start to go for larger magnification ratio (20:1) I want brighter illumination.

I recently tested the new Nikon D800E, which at a ratio of 10:1 acts like seismometer, and I found out that for my working environment this camera is too sensitive AFA vibration is concerned. Despite the 36 Mpix I have no gain in resolution compared to the 12 Mpix of my D3 but triple file size unless I can achieve an illumination which allows me to work with shutter times of 1/800 or shorter.



Edited 1 time(s). Last edit at 05/25/2012 11:59AM by Harald Schillhammer.
Stephen Eglinton May 25, 2012 02:18PM
Yes, i stumbled onto both the Visionary and IKEA products.

SO WANTED the Visionary system, but for two problems... never heard back (as well), and they do not bring it into Australia. Would have been perfect! Regardless, my thanks for your advice Harry.

The IKEA is brilliant, but simply not bright enough for the size i am shooting. However, i am still considering it for the few mm size specimens i have... yes, i think we all have them. Who's to quibble over IKEAs tiny price. Thanks Bart for the tip. It would work tremendously with my Jeffrey mine Grossular.

I was looking at the Leica LED today... NICE!!!, but again, underwhelming light output for any larger magnification. And the price... OUCH!

Any way, SO tired of trying to put together an appropriate, lighting system, i have ordered a Leica 150W system (with only two light guide arms). It was interesting to learn that to add a third light guide goose neck to a cold light unit means a drop in light intensity. The nice thing about the system is that light focusing attachments can be added. This sold me over Schott and Volpi. My Nikon D700 is still unused, sitting in the box for the last year. Maybe now, once the Leica arrives, i can finally start to upload pics to Mindat.

Cheers guys.
Kelly Nash May 25, 2012 03:11PM
It all depends on what you're after. Some people chase after the perfect system for years, and never get around to actually photographing very many specimens. I have a couple of Pictures of the Day here, that I am proud of though they aren't perfect, taken with a desk lamp and an old Nikon CP-990 that I got from ebay for $25, and which I use for nearly all my macros. It has 3.3 megapixels, which doesn't leave me much room to crop out tiny parts, but the optics and level of control (e.g. f-stop 9 or more at 2 cm. away) are superior.

I now shoot most specimens up to 5 or 6 cm. using a dual gooseneck microscope illuminator ($99). For thumbnails especially, it works well. I spread the light with pieces of frosted mylar taped to the ends of the tubes. A third light source would be nice, but not critical, two on either side of the camera pointed directly at the specimen are usually plenty. I have moved away from using my gooseneck halogens much because I got tired of burning my fingers and heating up the room.
Mineralogical Research Company May 25, 2012 08:08PM
I am using my FO illuminators for micro photography. When I say "difficult to position" I am referring to the problem of getting the light in just the right position so as to fully illuminate the specimen, provide some shadows and most importantly not have burned out reflections from crystal faces. So, positioning the lights is critical and may require as many as four sources. BTW, I find the focusing lenses on the light guides to be very useful in concentrating the light.

LED lamps that I have used do not have sufficient output for high magnification shots. Ikea type lamps are also problematic due to heat and low light output.

Stephen Eglinton June 03, 2012 09:27AM
Hey Gene,

Just got back. Thanks for your advice. Noted your experience with LED.

I have been given two choices with the Leica Cold Light fiber optic: 150W Halogen and 150W LED. I have seen the Halogen... 150W really puts out a lot of brightness. So i'll see how much their 150W LED produces, when it arrives.

Mineralogical Research Company June 05, 2012 02:59AM
Hi Steve,

After reviewing a number of articles on the current state of LED illuminators, it is apparent that the technology has rapidly evolved and is overtaking the Halogen illuminators in light output. Two major advantages for LED lighting, of course, are efficiency and long life. These new units appear to be far better than the units that I have tried. Unfortunately, the high output LED illuminators are still very expensive.

Can you give me details on the unit that you are getting? I would be interested in the specifications. Until such time that I win the lottery, I must resign myself to using my several surplus Halogen units.

One last note. I don't agree with some of the advertizing statements that manufacturers make for the LED illuminators. Several companies advertize 150W LED fiber optic illuminators and that is inconsistent with their specifications, which state a power consumption of 18 W. If they could get 150W out of a device which has a power consumption of 18W, I would be among the first to buy their stock! If they would say "light output equivalent to a 150W Halogen", it would be more appropriate.

Stephen Eglinton June 06, 2012 08:46AM
Gene, i would be only too happy to deliver on your query.

I will get in touch with the dealer so as to get the full run down on the LED model, and get back to you probably in a day or so.

Hope you do win the Lottery mate... judging by the obscene US Lottery pay out figure, you could afford to shout me the LED system:)-D

Stephen Eglinton June 09, 2012 07:52AM
Hello Gene.
Here's a copy of my discussion with the Leica dealer-technician, in regards to your query:

On 08/06/2012, at 1:10 PM, wrote:

Hi Steve,

Regarding the specs for the Leica 150W LED cold light source, I haven’t got much to give you since Robert is away for another 2 weeks and I’m quite unsure of which he had ordered in for you to look at. But hopefully it will come soon.

On Gene’s email in the last note part, he was spot on and I agree that it should be made clear to customers that a light source consuming 18W can give “light output equivalent to a 150W Halogen”. Since we all know that we can only get out (at best) what we put in, so to say getting 150W out of 18W in is not correct.

These energy saving lamps and LED lamps are much more efficient at producing light without creating much heat, which is the main energy waste in the Halogens .

Hope this help,

Thank you Quang for your reply.

I look forward to the specifications on the Leica 150W LED... as soon as you are able. I would access the specs if i could, but to obtain them from the Leica website is an impossible exercise... i don't know how long i was chasing them, eventually came away with nothing.

Staying tuned,

I'll get the specifications to you Gene, as soon as i receive them myself.(tu)

Very best,
Mineralogical Research Company June 09, 2012 08:17PM
Hi Steve,

As I mentioned before, I tried a few FO illuminators in the past and then resigned myself to the idea that they were not as good as Halogen illiuminators. Now that you have revived the subject, I am having second thoughts. Unfortunately, after a half a day researching the subject, I cannot reconcile which actually has more light output. It is clear that Halogen bulbs produce greater luminous flux than current LEDs, but there are other considerations such as coupling efficiency to the FO conduits. Here are the numbers.

Quartz Halogen efficiency = 24 lumens/watt So, 24 lumens/watt x 150 watts = 3600 lumens

LED efficiency = 100 lumens/watt So, 100 lumens/watt x 18 watts = 1800 lumens
(300 lumens/watt is the theoretical limit for LEDs, but because of the problems with keeping the LED junction cool, the practical limit is currently 100 lumens/watt.)

The above would lead one to believe that Halogen wins by a factor of two. However, to further complicate matters, one manufacturer states the following.

I am skeptical of the manufacturer's claims. My engineering experience tell me that it is theoretically possible, but perhaps it is not yet a reality. Ganging LED, through some type of optical coupler and efficient cooling methods would be necessary to beat the current output of the Halogens. Perhaps someone has solved the problem...

I also searched for information on Leica LED 150W sources and found nothing, even on their website. So, now you have me really curious as to what may be available. BTW, the LED "150W" illuminators that I have found range in price from $600 to $1300.

When I win the lottery, I will buy two of them for you. But don't hold your breath, because I don't buy lottery tickets. :-D

Stephen Eglinton June 10, 2012 03:41PM
Hi again Gene.

Read your message with much interest, and thanks. Yep, it is very involved!

Will get back to you with the specs, after i see the technician on Tuesday.

That manufacturers quote you presented, "Photonics" is mentioned. Along side Leicas' own equipment, Schott and Photonics both make FO & LED for Leica... with the Leica name stamped on them. It is the Photonics equipment i am looking at... the CLS range. Do not try searching for it, you will be wasting your time... i am not surprised you have found nothing. This was my experience as well.

I am now waiting for the LED kit to arrive to visually and photographically compare the two differing light types. Think i'll try both on a Dioptase, that will give them a challenge!

BTW: i can give you some prices:
The Photonics Halogen CLS 150 X (with mechanical & electronic brightness control AND separate constant & adjustable colour temperature): $Aust 1,171.
The Photonics Halogen CLS 150 XD (same, but with the colour temperature displayed on a meter... and a few other niceties): $Aust 2,126.
The Photonics LED CLS 150: $Aust 1,496.

I just found some earlier notes from the dealer:
"The CLS150 LED outputs about the same light as a standard halogen CLS with a daylight filter.

Remember however that the LED version has a blue color ie 6000K

Standard CLS halogen is 3400K

Standard CLS with a daylight filter is 5000k"

Oh, and Gene... a beer will suffice then.:)-D

Bye for now,
Reiner Mielke June 10, 2012 04:15PM
You can now buy high intensity LED spotlights (with many different types of light output) that put out almost no heat compared to halogens and last for ever. Yes they cost more, but if you factor in the life of the bulb, and reduced power consumption LED is cheaper. You have to keep in mind that the lumen rating is for the entire bulb so if you get a narrow beam bulb ( they come in different beam angles) the intensity per unit area is much higher as compared to a bulb of greater lumens but wider beam. see for example: As far as I know China seems to currently be the main manufacturer of LED bulbs so prices will vary depending on the middlemen involved.
Stephen Eglinton June 13, 2012 11:40AM
Checked out that website Reiner, thanks for the info.
Isn't asia the source for everything now days!!!

Stephen Eglinton June 13, 2012 11:47AM
Here is all the info i have managed to obtain on the Leica-Photonics Gene. Even the dealer ship said Leica is a sod to work with.
Hope this download works!


Edited 1 time(s). Last edit at 06/14/2012 07:33PM by Amir C. Akhavan.
Owen Lewis (2) June 13, 2012 05:23PM

That's a path to the desktop folder on your PC. Interesting but not a lot of use :-) If you can e-mail a copy privately to Gene, perhaps he would be so kind as to put it on his site and post a URL to it here?

It's an interesting thread. I've also pondered for a while on the (in)efficiency of coupling in my 150W halogen light box. I think it unlikely that the coupling can be more efficient than about 20% :-( If that's about right then the lower output LED approach should clearly deliver more payload onto the target.

Edited 1 time(s). Last edit at 06/13/2012 05:28PM by Owen Lewis (2).
Owen Lewis (2) June 13, 2012 05:26PM
Plese delete.

Edited 1 time(s). Last edit at 06/13/2012 05:30PM by Owen Lewis (2).
Holger Klapproth June 13, 2012 07:34PM
Hi Steve,

I came across the problem of not getting enough light out of the IKEA LED lamps on an excursion. We sorted that by fixing a 10x lens in front of the lamp to focus the light more tightly. That worked really nicely and may be the cheapest option to illuminate micromounts. As we were on excursion we just used sticky tape - and we had a well focused light beam that enabled us to see tiny things with our old excursion microscope (that just sucks up light...).

Best Regards

James Christopher June 14, 2012 03:45AM 12 volt, wide even light, and a natural color, and bright as well. I made one into a headlamp and it is way better than any of my other ones. It is dimmable by reducing the voltage, and the light is cool.
Greglee November 29, 2012 06:09AM
I am using led-source fiber illuminator. My experience tells me that it can not introduce more light from a source like a light bulb to an optical fiber that the optical power that an area of the source (filament) equal to the area of the optical fiber core emits within the NA of the optical fiber. So, the best way to introduce light from a white source to a fiber is to put the fiber very near the fillament or (better) try to use a lens to produce a 1:1 image of the filament and put the fiber there.
Owen Lewis (2) November 29, 2012 10:37AM
Why a 1:1 image? Given (say) a single 600um fibre core, ideally, would you not want all the light gathered and concentrated into a spot of not greater than 600um diameter at the fibre termination?

That said, some cold light gooseneck systems (like one of mine) do not transmit the light via a single fibre but rather through an approx 5-6mm bundle of such fibres.

None of the systems I use (QH(2) and Xenon arc (1)) utilises a lens system to improve the efficiency of light capture, using no more than elliptical(?) reflectors. Accordingly, all are quite lossy. They do the job though.
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