p.5 #1 · Flying projectile pass through a falling droplet.
wow!
Frans this is an awsome setup and you get some of the most interesting photos I have ever seen from it. I cant wait to see your results once you get everything tuned in. I cant get my head around half the stuff in this post , but its great to see someone use their technical power for fun instead of the evils of work I swear if the engineers at work had a hobby like this they be much nicer people
p.5 #3 · Flying projectile pass through a falling droplet.
Thanks Adam Connah and GOVA.
Today, one groep leds is finalised. I have put the power via a resitor to check the different lenses at only 100mA to start. Tomorrow I will use the camera to check how much light I have. A few closeup pictures of one complete unit:
The next photo give a detail how the units can turn in each direction to adjust the lightbeams to the photoplane.
The last picture show the powerconnection. Each unit of 2 leds can be connected separately to a power connector block. The power is 24V and a LM317 regulator set the max current at 1.0 Amp. 4 leds are on one circuit. On the controller an IRF740 fet drive this circuit at the right moment. This time can be set on the keyboard entry between 10 usec and 100 msec at 10 usec intervals. Resolution is 1 usec.
Now I can already say that the narrow lens give really the most light. The medium and wide lenses are unsuitable, only the norrow lens and the Fraen Elliptical Beam are useful.
Frans.
p.5 #6 · Flying projectile pass through a falling droplet.
Dalantech wrote:
I'm curious to see your LED results Frans -thanks for sharing your technique and hardware with us!
Well tomorrow I will put the camera on a graycard to see the amount of light.
Shots with waterfigures could not be possibly considering only one complete unit is ready now. But with this measure I can interpolate the results for all the modules. I'm afraid not having enough ligh at 200 usec flashtime. Now the camera is set at ISO 200, this can be boost to ISO 800 and the diaphragm now at F20 can be lowered 1 stop. I have to test it if the 200 usec is really a limit or if I can go longer. The lightspectrum is not critical for this application, even blue light is better for waterfigures.
We will see tomorrow !
Frans.
p.5 #8 · Flying projectile pass through a falling droplet.
Thanks ELWOOD B!
I have worked the hole day to connect the highpower leds as flash unit. Also a lot of timings into the controller have been adapted to this new logic. Time to connect the hole new flash unit and to make test shots.
Results: YES ! it works!
Unbelievable but the results are really close to my expectation. With only 1 group ( planned 5 groups) I had set the camera at F8, ISO 400 this is near 3.5 stops lower than formerly. The leds are pulsed for 200 usec and the first picture was correct! Ofcourse because of only one group the leds gives not 100 % equal light on an white surface but this can be adjusted by putting more groups. For this application like the waterfigures, this is not so critical because shadows may give an extra creative dimension.
The results are so good that as opposed to previous postings I have taken new waterfigure pictures. Nothing special ofcourse, but just to see how the new ledflash group will work into the real world. And as expect the reflections give mostly 4 points but the points are smaller. Ofcourse this first group stay in front, next groups will be more into the background.
But first now a few results:
The first 2 pictures are without backgroud lighting, the last with. The background is provide by a normal flash ( vivitar 283 at low power). The picture 1 and 2 are with a led flashtime of 200 usec, the last with 600 usec. As far I can see now, 600 usec is not a problem to freeze the action. So the camera was set into picture 3 to F8, ISO400. This is really better than expected. Adding 3 extra groups will give me 2 extra stops. So F11 and ISO 200 or F16 and ISO 400 will be oké into the full version.
But now I can drive this leds multiple times into the same picture. If I drive 3 times the leds with an interval of a few msec, I must see the evolution of the waterfigures into the same picture. I think to drive the background also with 3 normal flashes but at 1/3 of the current power so that this part will by normal lighted ( multiple lightings into the same picture need lower initial lightings!) Ofcourse this test are reserved for the full setup of the 4 or 5 groups. But this construction take time. I have to design and draw the hole setup again and need more extra narrow lenses on the leds because I have only a small number of this lenses now. I believe this take minimum 3 to 4 weeks.
The distance from the leds (pcb) to the fotoplane is about 10 cm. This distance is really important for the correct lighting.
Yes, for me this is really fine to see all the efforts give results.
Frans.
p.5 #10 · Flying projectile pass through a falling droplet.
greeneggs wrote:
"But now I can drive this leds multiple times into the same picture."
I hadn't thought of that, seems like there is a lot of room for exploration. Doing this with flashes might be prohibitively expensive.
Yes, to expensive as I need 4 flashes/ light pulse, so if you want 3x lighting into one picture this will be 12 flashes as I have not the possibility to fire the same flash multiple times with a short programmed interval.
But there is more, I have also the 3 color versions of the highpower leds. By using the narrow lenses on the leds, I can focus some colors on a part of the picture ( example upper part). This must give some color gradients.
Tomorrow I will try to use multiple lighting pulses into the same picture. But first I have to adapt the controller for this new timing functions. I need multiple timers as interval, programmed from the keyboard. I believe the capture range is about 10 to 15 msec so the intervals are into the range of 5.0 msec.
Frans.
p.5 #12 · Flying projectile pass through a falling droplet.
Thanks Kevin Theron!
I need more time to adjust the controller for multiple ledflashes into the same window because the add of multiple new timers and counters. In the meantime, I work on the mechanical parts of the next ledflash blocs. But first I like to give a overview of the timing sequence for the capture of this type pictures. First the drawing:
Not all the timers are show, only the basis for a "simple double spalsh". The camera is set to 1/200 sec, this give a marginwindows of 5 msec to drive the flashes or to drive the flashes multiple times to view the development of the figures. If necessary, setting the camera to longer time prolong this window. For this application I no longer use my second shutter so I subtract the 52 msec camera delay from the total delay T4 to set the T3 delay value. Everyone can do this with the most camera's if you know this delaytime. An extra second mechanical shutter is only need for flying insects because you never know exact when the are flying to the laser system.
For a double splash ( second droplet falls to the returned first) I use a second laser close to the dropllet output to detect the first droplet and to set the delay before the second droplet must start. All other timings are derived from detector2. The timings for the wavegenerator used for the waterfigures are not show into this example to hold the drawing orderly.
Frans.
p.5 #14 · Flying projectile pass through a falling droplet.
Thanks Jim!
Today I have just received my new order lenses and a few extra leds. This week I have worked on the mechanical parts to put the color versions. But this is really a lot of work! So many items! Now every led can by turned into any direction:
The mechanical parts for 2 colors units ( each 4 leds) are ready now. Still the electrical wiring and it's ready for the new test. I have now more narrow lenses of 6 degree and will concentrate the light on a small point to the picture to see the results of the colors on my waterfigures.
I have also 2 special UV 400 nm highpower leds of 300 mW UV radiation. I like to test this UV leds for the caption of flying insects into the dark. The same highpower leds can by used together with multiple flashes for this concept. 400 nm UV is not the ideal wave, better is near 380 nm but today the price is to high for lower UV range leds. I hope the insects like to see also this 400 nm versions!
I like to take again pictures this sommer of flying insects like the results from 2006:
But first the led tests on my waterfigures, I hope next week to take again some pictures.
Frans.
I cant wait to see your results once you get everything tuned in. I cant get my head around half the stuff in this post , but its great to see someone use their technical power for fun instead of the evils of work 
I swear if the engineers at work had a hobby like this they be much nicer people
