I assume this is what im after here >- http://dse.resultspage.com/search.p...d=4278d62b0b9c7c622740c0a87f990747&method=and
not badly priced i guess.
not badly priced i guess.
link dun work.. add the H and try htis
http://www.dse.co.nz/cgi-bin/dse.storefront/4278d62b0b9c7c622740c0a87f990747/Product/View/Q1367
$60 US
http://www.dse.co.nz/cgi-bin/dse.storefront/4278d62b0b9c7c622740c0a87f990747/Product/View/Q1367
$60 US
Rox, if you use the pre-condenser to compensate for a longer FL fresnel or smaller LCD, then the lamp arc will appear to the fresnel as the same.
DJ
DJ
the arc will come from the same point for the fresnell (focal point) but the lamp will be virtually larger.
A pre-condenser lens will do 2 things to the arc:
1) make it virtually larger
2) make it look farther.
i can xpalin it to you in terms of math if you want.
A pre-condenser lens will do 2 things to the arc:
1) make it virtually larger
2) make it look farther.
i can xpalin it to you in terms of math if you want.
An externally hosted image should be here but it was not working when we last tested it.
this is the idea i mean.
Rox said:
If any of you DIY Projector types are interested, I have a bunch of Texas Advanced Optical TSL230 "Light to Frequency" Converters, and TCS230 "Color to Frequency" Converters -- you just use a counter like a PIC or AVR to read the pulse duration to measure light intensity.
TAOS was part of Texas Instruments, the devices have been used with microcontrollers and much discussed in the pages of "Nuts and Volts".
email me privately if you care.
There is an answer; it is to use a corrected pre-condenser or corrected reflector. Possible experiment that I haven’t tried is to use a pre-condenser back to front.
DJ
DJ
i never understood what you mean by this "corrected".
Can you xplain it basically what do you mean dazzla?
Can you xplain it basically what do you mean dazzla?
Rox your pic shows exactly what I mean. The lamp appears to the fresel as is it was at the fresnel’s FL.
DJ
DJ
yes, we have to do it that way (mean conbining the focal lenght on the pre-condenser lens and the placemt so the virtual light is at fresnells focal point exactly. I agree with it. But look that the virtual arc is larger than the real arc, (that is not a good thing at all)
When I say corrected, I mean that the plain spherical lens has had some sort of modification to the shape of the lens. Instead of the lens being a constant radius, the radius is different at the edges compared to the centre. An aspheric lens is a lens that has had its shape changed to correct for spherical aberration.
DJ
DJ
Rox ray trace that virtual arc through the fresnel to the objective lens and compare its size to the arc coming from the rear fresnel’s FL.
DJ
DJ
Hint!
In elipsoidal stage profile spotlights, the field is peaked or flattened by moving the lamp within the reflector...😉
In elipsoidal stage profile spotlights, the field is peaked or flattened by moving the lamp within the reflector...😉
Dazzzla said:
Sorry i don´t follow you.
Do you mean to compare the arc size on the objetive lens of the setup with the pre-condenser lens and the setup without the precondenser lens?
setup 1) arc 220/330
setup 2) arc pre-cond 330/330
so i can compare the two arcs on the lens ,is this what you mean?
A bit more info for what I’m suggesting for a modified pre-condenser, An normal aspheric condenser has been modified to make the rays coming from the outer edges of the lens to focus further than a un-modified lens, if we could get a lens modified so that the outer rays focus closer than it’s FL then when used as a pre-condenser the resulting light should be more concentrated at the outer edges of the rear fresnel. I think this would be a much better solution than wasting the light from the centre by blocking it.
Sorry for th long sentence
DJ
Sorry for th long sentence
DJ
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