DIY Jansjo LED fiber optic light guide

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ztt74
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DIY Jansjo LED fiber optic light guide

Post by ztt74 »

I had someone ask (anvancy) about a modification I performed on a Jansjo light in this thread https://www.photomacrography.net/forum/ ... hp?t=36087.

Image

Searching the forum, it appears that this hasn't been discussed here before, so here are the details:

Firstly, this is NOT my idea: full credit must go to the creator on this page https://www.gemologyonline.com/Forum/ph ... 21&t=18097

Here are a few images and instructions to help those who wish to perform the mod.

Image

In addition to the Jansjo light you'll need a wine bottle cork (the happy by-product of wine drinking) and a "Universal Tip Guide Optic Fiber Rod for Dental Curing" - i found mine here on Aliexpress
https://www.aliexpress.com/item/1-PCS-8 ... 90351.html

The cork needs to be cut to about 1cm long, and then a hole bored into the centre of the flat side of the cork. Examine the cork before cutting - they are usually thinner at the top end of the cork (i.e. not the end that is in contact with the wine when the cork is in the bottle), and the top end fits more easily into the Jansjo lens holder. I used the blade of a small penknife to bore the hole, but you have to be slow and methodical to avoid the cork splitting or cutting yourself - it just so happened that the width of the blade i used was almost the same as the width of the end of the optic, but you want the fit to be quite snug.

Image

Next fitting to the Jansjo. Using a thin blade, gently prize out the lens and lens holder from the Jansjo light by sliding the blade in at the top or bottom (where the screws are visible) between the black lamp housing and the clear lens holder.
Image

Once you have freed the clear plastic lens holder, slide it over the end of the cork. There are two holes in the sides of the lens holder that clip into place when inserted into the light housing - the cork should not cover these holes.
Image

It easier to get the cork inserted into the lens holder, then inserting the fibre optic rod into the hole in the cork, which, if you made the hole sufficiently snug fitting, should push the cork out slightly and create a secure fit with the lens holder.

Comparing the output (the head of each Jansjo is at the same distance from the paper), the removal of the original Jansjo lens makes a noticeable reduction in the yellow fringing around the edge. Left the Jansjo LED fiber optic light guide, middle shows a 10x loop attached, and right the unmodified Jansjo. Perhaps the biggest benefit is the ability to more precisely position the focused light from the optic rod. I cut a small disk from a ping pong ball just slightly larger that the tip of the optic rod, and attached it with tape to produce a more diffuse light.

Image

In place on my rig.
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jon

edit - moved this to this forum after accidentally posting to the "Macro and Micro Technique and Technical Discussions"
Last edited by ztt74 on Fri Dec 22, 2017 10:01 am, edited 1 time in total.

tevans9129
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Post by tevans9129 »

Very interesting and seems to be a very good mod, thanks for the images and explanations.

ray_parkhurst
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Post by ray_parkhurst »

very nice, I had not seen such a snoot used before. will give it a try.

rjlittlefield
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Post by rjlittlefield »

That's a great mod. Somewhat similar mods have been discussed before ("Shrinking the effective size of an Ikea Jansjo lamp"), but the use of this dental fiber optic rod seems more elegant than any of the tubing or acrylic rod suggestions in that thread.

--Rik

Pau
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Post by Pau »

Very nice!
Firstly, this is NOT my idea: full credit must go to the creator on this page https://www.gemologyonline.com/Forum/ph ... 21&t=18097
All us take ideas from other people, this is how Science and Technologies advance. Just don't try to patent it :wink:

It seems that you're putting the fiber optic very close to the LED, the most effective solution. A similar idea in a more complex setup was discussed at:
http://www.photomacrography.net/forum/v ... p?p=197014

Does the lamp heat more than the original lamp?
Pau

ztt74
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Post by ztt74 »

thanks all. it is very simple to implement and quite cheap - under $10 + bottle of wine. One thing to note is that I havent tried synthetic corks yet, so I am not sure how they will work.

I think this potentially allows more jansjo lights to be deployed to illuminate a subject. Still learning about the best methods for lighting though, so if anyone has a good guide for the best strategies for lighting (i know this will depend on lots of factors - subject, optics etc)then please point me in to those resources.

Pau, yes the fiber optic is almost plush with the led. I measured the temperature of the light housing after and hour of continuous run (with a IR thermometer) and found that all three lights (snoot, loop and stock) ran at the same temperature of 30.5 deg C (+/- 0.5 deg C), so it appears to not significantly change heat retention.

I was a bit nervous about putting combustibles such as cork in close proximity to the led but so far i have not encountered a problem, and the temperature readings suggest that it should not be. I do not leave the lights unattended though, and recommend that other do not either.
I actually also bought some Sugru mouldable glue (which i understand is a silicon based compound that can stand hight heats of ~150 deg C) to fashion a more permanent holding for the optic, but have yet to try this yet.

I saw the thread you had alluded to but i think that was beyond my technical skills currently so went for the fiber optic low hanging fruit, so to speak. The snoot avoids the need for any fans, so will reduce potential vibrations.


If anyone else tries this, please to report here how it performed for them.


Jon

Pau
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Post by Pau »

:idea: This approach could be implemented on the popular Convoy S2 Nichia UV flashlight* for fluorescence as the fiber optic tip seems designed for UV cure and would allow to put the light source much closer to the specimen with microscope objectives.

* see: http://www.photomacrography.net/forum/v ... p?p=204217
Pau

rjlittlefield
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Post by rjlittlefield »

Pau wrote:the fiber optic tip seems designed for UV cure
Do you see it specified that these are for UV? I ask because I happened to talk with my dentist about his light a few days ago, and he said they used to use UV but then the industry realized they were sunburning people's mouths and switched to blue-light curing compounds. So I think there is a possibility that modern tips, especially cheap ones, could be made of some plastic that is blue-transparent but not UV-transparent.

--Rik

ray_parkhurst
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Post by ray_parkhurst »

rjlittlefield wrote:
Pau wrote:the fiber optic tip seems designed for UV cure
Do you see it specified that these are for UV? I ask because I happened to talk with my dentist about his light a few days ago, and he said they used to use UV but then the industry realized they were sunburning people's mouths and switched to blue-light curing compounds. So I think there is a possibility that modern tips, especially cheap ones, could be made of some plastic that is blue-transparent but not UV-transparent.

--Rik
You must have a very progressive dentist. Mine, and others I've heard about recently, are still using UV.

Perhaps the snoots are plentiful and cheap now because they are the UV kind and are being surplused/phased out for blue light?

I'm also curious about the strength and chemistry of blue-light curing. UV cure works because of the high energy levels. I'd think blue cure would take much longer and would have weaker bonds.

Chris S.
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Post by Chris S. »

Jon,

Well done! :) This is a nice and useful addition to our pages.

May I suggest we follow the lead of the fellow at GemologyOnline and call this a "DIY fiber optic illuminator," rather than a "snoot"? Both the terms "snoot" and "fiber optic illuminator" already have established definitions.

I don't mean to be pedantic, but to make things clearer in discussions and easier to find in searches as time goes on. This thread is likely to be referenced in the future.

Cheers,

--Chris S.

ztt74
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Post by ztt74 »

Hi Chris,
I agree that "DIY fiber optic illuminator" or even "DIY LED fiber optic illuminator" is much more informative than snoot for future reference. Should I edit the post title to reflect this change?

Cheers,
Jon

lothman
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Post by lothman »

rjlittlefield wrote: Do you see it specified that these are for UV? I ask because I happened to talk with my dentist about his light a few days ago, and he said they used to use UV but then the industry realized they were sunburning people's mouths and switched to blue-light curing compounds. So I think there is a possibility that modern tips, especially cheap ones, could be made of some plastic that is blue-transparent but not UV-transparent.

--Rik
I wanted to use those cheap dental lights in order to cure the glues used for fingernail modification (also very cheap for mounting small items) but the dental stuff seems to cure in the range about 400nm and the fingernail stuff is more on the <360nm site. So the fingernail glue does not harden with dental LED version (or it has to be signed "led compatible" or such things).

Old UV curing lights (with filament light + filter) had a broad emission, those dental curing light seems to be near blue light and not so much in the UV range. Then I changed the LED from the dental version to UV-version but the emitting power was too small, it took too long to harden the glue. So I gave up.

But a dental UV curing light probably could be easily converted to a whitelight torch by swapping the LED. Could be very handy in small places

enricosavazzi
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Post by enricosavazzi »

rjlittlefield wrote:
Pau wrote:the fiber optic tip seems designed for UV cure
Do you see it specified that these are for UV? I ask because I happened to talk with my dentist about his light a few days ago, and he said they used to use UV but then the industry realized they were sunburning people's mouths and switched to blue-light curing compounds. So I think there is a possibility that modern tips, especially cheap ones, could be made of some plastic that is blue-transparent but not UV-transparent.

--Rik
Acrylic (as long as pigments are not added) is very transparent to NUV. So most of these light guides are probably UV transparent even if not specified for UV. The very same rods will work fine also with blue LEDs, of course.

There is for example suntanning-grade acrylic sheet used for suntanning beds. By buying it you are sure it does not contain pigments. It is otherwise just plain acrylic/perspex/Plexiglas.
--ES

Chris S.
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Post by Chris S. »

ztt74 wrote:I agree that "DIY fiber optic illuminator" or even "DIY LED fiber optic illuminator" is much more informative than snoot for future reference. Should I edit the post title to reflect this change?
Jon,

I went ahead and made the edit for you as "DIY Jansjo LED fiber optic light guide". Does that sound good to you? Adding "Jansjo" seemed additionally helpful, as so many members of this forum use these particular lights. I also got to thinking that in typical parlance, you are using the Jansjo as the illuminator; what you've added is a very nice fiber optic light guide for it. This terminology is parallel with that used for halogen illuminators and fiber optic light guides.

Cheers,

--Chris

anvancy
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Post by anvancy »

Thanks Jon for putting up this thread.

I have bookmarked it and will go through the build process.

We dont get IKEA lights here in India, so if the process of removing the cover goes bonkers, I am left with two lights.

Yes the base light coming from the Janso is too spread out. Ofcourse its a reading light so cant complain there.
www.anvancy.com

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