# handheld gobo projection (return of the bat sign)



## yosh (Apr 19, 2011)

hi all, first post.
im looking to mount a sillhouette to a flashlight for a theater effect (as in people projecting words and texts on the scene). 

what i hope to find is a strong led based light source with focusable lens where can drop my sillhouette and project (brightly!).

here is some tests i did with a modified small theatrical gobo projector light.
i replaced the 12W halogen with a LED (3W, M16 type mount) and placed a slide before the first condenser (condensor?) lens.







[result] 





related threads - 
bat sign hack
gobo projector search

i always saw this forum as *the* source for extreme light fetishes so hope someone can help.

yair


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## Bullzeyebill (Apr 19, 2011)

Moving this to Special Application Lighting.

Bill


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## yosh (Apr 19, 2011)

might focus this: whats the most lumans i can get in the M16 package?

also of intrest: Projection with LED Light Sources. Application Note (pdf)

* 20W Warm White High Power 1000LM LED Lamp Light 12V (1500mAh fwd) [EBAY] via DIY LED PROJECTOR [VIDEO]

* is this for real?!




http://www.ledpower.bg/product_info.php?products_id=21001409


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## yosh (Apr 20, 2011)

so thats the forum graveyard 
i'll try to update as i go fwd, 
i was at a club yesterday and some bored uncool guy started playing with his camera-phone "led torch", blinding everyone around. 
i approached and started playing with his torch (), did some hand puppeteering, those thing are bright for their size. 
and im sure a proper led torch is so much more. i guess i need to focus on good optics.


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## Walterk (Apr 22, 2011)

You will need a single emitter, with an emitting surface comparable with the bulb that originally was used in the projector.
After that I guess its mainly in the lenses. 
See that you understand throw with Leds, in other words ' surface brightness', ' focal distance from lense' and 'die-size'. 

You ve got a nice test setup, so I guess a Cree XRE Led and some experimenting will get you close.

IOW: dont use a standard Led-replacement bulb!!


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## yosh (Apr 22, 2011)

thanks Walterk for breaking the silence, 

i went over your focusable sst-90 thread, gave me an idea to try some projector lens i've got from a defunct infocus projector.

in the following image are the relevant internals of the dismantled projector, including: 
1. the projector lens
2. original light source ( high-pressure metal halide lamp)
3. original image/video source









i took apart the factory light and image sources and placed my slides instead

getting good projection (no photo as i was holding everything by hand)










i'm still looking for the perfect light source, i ordered a few parts and will try them out, my 3W M16 LED is nice for testing but its surly not enough. 
i'm looking for total cost of parts at the range of 20-30$
(excluding the projector optics, which i think i can get a few from a repair shop).


i think i need:
power source (batteries, gel cell is OK)
fan or heatsink - from dead PC's
led driver - (this one for the P7, as for the SDP20 i dont know yet)
led - (ssc P7, SDP20-20W - but above budget @ 50$) 
lens - 28mm ?

and how about this kit? [edit: not good as the driver is AC in]


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## yosh (May 22, 2011)

comments on driver and the vaibility of using such inefficient LEDs in battery operated design in this thread
going to order a few XM-L cree to experiment with more efficient "of the shelf" design.


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