I my self evaluate DrJones’ articles one of the best sources on the net for our hobby.
luminarium iaculator that is a beautifully machined flashlight there and i really like what i see. in my case covering to one smaller lens need a lot of extra work in my SYRI. till the moment i manage to build one i can not give precise answer how it compared with this big lens i have now.
but i make some quick measurements and the results are little bit unexpected to me.
i measure lux only with big main lens without precollimator and compared it with precollimator on.
i was expecting that dual setup performed little bit less regarding throw because of loses introduced by precollimator, but in fact i got the opposite results
3.5m with precollimator i got ~126 reading on my light meter 3.5m only with main lens i got ~116 reading on my light meter
i was expecting the opposite. repeated the test another day and again get ~ the same e difference 128 with 120 in favor of dual lens setup!!!
i have thinking about this these days, and this is how i can explain: 1. measuring @3.5 meter disfavor single lens setup. the spot is not well formed and is that small that fit in the white part of light meter. with the dual setup the spot is much bigger in my case and i can easy find the “hottest” part of the die and measure them. 2. in single setup i hold the main lens with hand trying to make the perfect focus and maybe i have not managed to do it correctly(but i repeated for this reason the measure and get same results ) . in dual lens setup everything is more than precisely calibrated. 3. my big precollimator lens act as some sort of collar together with the part that i build to hold the lens. i have an idea how this could be happening and will make an diagram later to explain better what i mean. if this is the case for sure was an pleasant surprise to me because was unpredicted by me when i build the light.
this is tricky. the main lens is not focused on the die, it sits near. also the precollimator. but if we look at the dual system as one big lens than we can say that this “hybrid lens” IS focused on the die. not much time now will try to make an diagram later.
What I know is that in certain configurations light intensity or candela of certain flashlight could be increased for 70% or more % by using doubler type of lenses.
Doubler? Telephoto lenses for dsrl cameras with x2 magnification.
What could have happen here is that you probably have very low profile 100 mm lenses (but still not as low as doubler) which acts similar as doubler lens and it is quite possible that you got slightly better results with precoolimator than without it.
With higher profile lenses like dereelight(right lenses on upper picture) you would have decrease. But you have flat one.
Hint: Try to order 52mm telephoto lens and try to put it over UF T20 lenses candela will rise for more than 70% with tighter beam profile.
I have seen a lot of mods on T20 flashlights using this doubler so in this case doubler( which is constructed of 2x lens system) so when you put doubler over uft20 main lenses you have triple lenses system and real gain in throw. If you have 100kcd uft20 it will jump somewhere to 180kcd+-
Very cool stuff going on here! Fantastic build, I especially like the copper cooling coils!
I’m not sure if you mentioned it but could you give the source for the main lens used in this build?
its interesting to me this design because i have done this myself some time ago :
and indeed i can confirm it throw further, but let me disagree on the reasons why . IMHO i think that the gain is correlated to the different surfaces the two lens have and not to the shape and different f they have. more info on my build and the theory here:
@ LinusHofmann
thank you, you sure know how to make superb build too it seems, I am constantly checking your thrower build
the main lens is from fasttech
playing around with my flashlight i wanted to test its burning capabilities :bigsmile:
this is my old dream and with pure throw i was able to realize it .
first i make an measurement test to see what can be done with the beam :
sorry for the mess it was a quick try with my hand bag that i carry with me every day, it burn a little but not a problem
than the real test :
it was a fast fire with the right lenses the setup could be smaller, way more smaller and i am working on it
i have made some new long distances beam shots but not much time to post now
its strange, i am trying all possible ways to put the video, the sec one is now working the first one not yet, but you can see it in direct link in the middle. is there any kind of policy on youtube or here that restrict some kind of videos maybe, that I am not aware ?
by the way for you that can see the videos can you replicate the results ? the probe on the first video measure the tem. in grade Celsius as shown in multimeter. i stop at around 170 C because of smoke and was afraid of damaging probes. I am just curious because i think is somehow correlated with the fact that my zoom have hi performance in total lumens too apart from throw. but if can be done without precollimator than clearly its not the case. amps on my case are around ~4~4.5 i believe. (was testing with 3 panaB protected @4.1 V and not with sony hi drain that I use for max results )
in the sec video of putting the mach on fire i use another stage of lens to tighten beam more, because only with one lense it needed more time and it was harder.
i am doing some basic maths, the led is burning around 15W of power but lets say only 5W is emitted as light. if i am capturing 70% ~80% of this light and projecting it in the beam that i should have ~3.5W minus some loses from optics than maybe i have ~2.5W on target? hm … I have not enough expertise in this area so i can be wrong of course.
) . in dual lens setup everything is more than precisely calibrated.
