Light Source for fibre optics

[cws1745]

Apologies in advance if this isn't the right place to post thsi question, but .....

I've managed to get a fibre-optic 'gooseneck' which I intend to use in my macro platform. However, I need to build a light source for it and plan to use a cob led for the light source. I have just finished my led moth trap using 3W leds but I have also got 10W, 30W, 50W and 100W cobs which will produce much, much higher light outputs. I'm currently thinking that the 30W led with a dimmer control will do the job?

This is one of very many areas where I do not have the theoretical knowledge and seek some help. Can I just make an enclosure with appropriately cooled light source and let the light bounce around inside - or do I need to 'channel' the light towards the input of the fibre-optics? I believe the term is collimate the light.

Any pointers much appreciated.

Charles

[Pau]

Charles, this topic has been discussed in several threads, you can find them with the keywords fiber optic and LED at our site

I think the most complete one is
http://www.photomacrography.net/forum/v ... optics+led
in particular from this post
http://www.photomacrography.net/forum/v ... 481#197481

[dolmadis]

Have you seen these?

https://www.ebay.co.uk/itm/VOLPI-INTRAL ... %7Ciid%3A1

[cws1745]

iHi,

Saw the listing before - but I dont't like the idea of a halogen light source which must be extremely hot with short life-span.

I thought about buying one to cannibalise any lens / reflector but decided against it.

I've just finished an led moth trap using 3W leds and was really surprised at the light output. Got much bigger cob leds so if I can work out how to concentrate the output to the gooseneck I'll be a happy man!

Unfortunately, optics is a subject I know practically nothing about so I'm anticipating that I'll need to use a reflector and lens to collimate the light?

Not wishing to re-invent the wheel so hoping to find others who have done the leg-work already! They say plagiarism is the best form of flattery!!

Best

Charles

[dolmadis]

No problem.

As it would be off topic to discuss here would like to see your design for your moth trap by PM if possible or another post wherever appropriate on the forum.

How much UV is there in your LED output?

What catch size/diversity do you get?

BR

John

[cws1745]

Pau,

Thanks for the links. Following the link and the links from the link etc etc etc

The heatsinking, the dimmer, the psu I'll cope with - concentrating the light source at the end of the gooseneck and any optics etc will be my struggle.

One day I'll actually finish the hardware and take a stack of photos!!

best

Charles

[JKT]

Another vote for the moth trap details!

[Scarodactyl]

Just for the record, a 150w halogen source doesn't get particularly hot. They're designed to dissipate heat and are reasonably effective at it--the part of the box right in front of the bulb gets pretty warm but you'd have to go out of your way to feel that. Anything you're going to touch will be fine, you'd just need to wait for that front bit to cool before swapping light guides. Maybe if you were working in a very enclosed space it could be an issue? The bulbs tend to be rated for something like 1000 hours of use and are not that expensive to buy and are easy to replace. That's not to say you shouldn't experiment or that I'm not interested in what you come up with, just saying halogen light soirces really aren't a big hassle and needen't be dismissed out of hand. There are also equivalent led sources available used, though I haven't tried one myself.