Thx Enrico, for a moment I thought this could be easy. However, I'm willing to try some of the solutions discussed so far.
Concerning collimating lens I have found this one:
http://www.ebay.at/itm/3-Stueck-5-Linse ... 0952529587
Its german text, but it says lens diameter is 20 mm, emission angle is 5 degrees (there are others with larger angles), the lens can be removed from the case. I can't see the construction details of this thing, but for that price I would just try it.
Construction of an LED-light
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enricosavazzi
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These are collimators for individual power LEDs, apparently mounted on the usual hexagonal carrier, like the Luxeon LEDs. For a LED cob you need a different type of collimator. The lenses I am thinking about have a diameter of 40-50 mm. I cannot search on eBay right now, but I have seen plenty of these cob collimators from sellers in China.
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Charles Krebs
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keks,
The power (9w) and size specs (~10mm emitter surface) of the Yuji LED you mention is very similar to the Brideglux ones I used for my lights. I've used them heavily for over 1/1/2 years now and they have been great.
Initially I would not spend a great deal of time trying to work out collimating lenses or diffusion surfaces. I have found it to be beneficial to keep the lights simple and provide diffusion separately based on the subject and the requirement of the lighting. It will vary enough from subject to subject enough that I think I would feel constrained if I had attached more than the (removable) narrow-angle Ledil reflector (C13085_MIRELLA-50-S-P) to the front. I have also found the small snap-in diffuser (C12479 Mirella-DL) useful.
http://www.ledil.com/lett/application_e ... 060214.pdf . The front edge of these reflectors is about 50mm in diameter, and I have added adapters that allow me to use 49mm polarizers for the occasions when polarized light that is helpful.
If, after some use, you feel that you are not getting sufficient light on the subject because of excessive "spill" then you can re-visit a collimation solution.
If you have not seen this thread it will give an idea of what I am talking about.
http://www.photomacrography.net/forum/v ... hp?t=27265
The power (9w) and size specs (~10mm emitter surface) of the Yuji LED you mention is very similar to the Brideglux ones I used for my lights. I've used them heavily for over 1/1/2 years now and they have been great.
Initially I would not spend a great deal of time trying to work out collimating lenses or diffusion surfaces. I have found it to be beneficial to keep the lights simple and provide diffusion separately based on the subject and the requirement of the lighting. It will vary enough from subject to subject enough that I think I would feel constrained if I had attached more than the (removable) narrow-angle Ledil reflector (C13085_MIRELLA-50-S-P) to the front. I have also found the small snap-in diffuser (C12479 Mirella-DL) useful.
http://www.ledil.com/lett/application_e ... 060214.pdf . The front edge of these reflectors is about 50mm in diameter, and I have added adapters that allow me to use 49mm polarizers for the occasions when polarized light that is helpful.
If, after some use, you feel that you are not getting sufficient light on the subject because of excessive "spill" then you can re-visit a collimation solution.
If you have not seen this thread it will give an idea of what I am talking about.
http://www.photomacrography.net/forum/v ... hp?t=27265
Hello Charles, thats a nice solution with the Bridgelux parts, if I had seen that earlier, I would probably have gone that way.
However, in between I have done some testing and found a nice (seems so) solution with a collimating lens placed directly in front of the LED. This lens is kept in place by a short aluminium tube which in some way also serves as a reflector. The LED is glued to a heat sink with arctic silver.
Just for comparison I have bought a Jansjö and found my own construction a lot better.
I will post images as soon as I have assembled that thing properly.
However, in between I have done some testing and found a nice (seems so) solution with a collimating lens placed directly in front of the LED. This lens is kept in place by a short aluminium tube which in some way also serves as a reflector. The LED is glued to a heat sink with arctic silver.
Just for comparison I have bought a Jansjö and found my own construction a lot better.
I will post images as soon as I have assembled that thing properly.