I need to make a Bat Signal

[2100]

I tried playing with it, there is no way aspherics would work as a bat signal even on a building no matter at which focal point for our flashlight type aspherics. And if its bright enough there is no way the big emitter is going to do that with a good throw.

Your best bet is as mentioned earlier by me (1) laser, which isn’t that expensive….and (2) searchlight.

Less than 1k shipped.

Matin 575 Moving Head light

[2100]

But if one is not on a flashaholic batman signal pursuit, then those small batman flashlights are good for home use! Just nice for halloween (but too late to buy and ship over i guess).

[willie]

My green PT120 has a large rectangle projection with a aspheric lens. Stainless shim with a bat on the led lens would produce he desired results with an aspherical lens. This led is capable of 3500+ lumen. But can you live with a green bat?

[antonkochubey]

@willie

My green PT120 has a large rectangle projection with a aspheric lens. Stainless shim with a bat on the led lens would produce he desired results with an aspherical lens. This led is capable of 3500+ lumen. But can you live with a green bat?

Well, can’t the green PT120 be replaced with white CBT-90? :Р

[Extra_Bright]

@MountainKing

You mean an ultra sound device for repelling bats? Im looking for something cheap that would do this too

Why in the world would you want to repel bats? They eat mosquitoes. 0:)

We have a bridge that I go by on my weekly hikes, and I love to go down and try to catch a bat in the viewfinder. Those things are fast!

They used to build large bathouses here in an effort to control the mosquitoes back in the early 1900’s

[Extra_Bright]

@2100

Oh….actually can just use any focusable laser pointer, what you want to do is to make the point source have a wide divergence (eg 30 deg beam). Put a ~ 4X 75mm diameter magnifying glass that you can get from ebay, focus it nicely so that you have a big spot in the distance. Cut a batgirl/wonder woman/ironman sign and place it on the magnifying sign, You could get those 8-12 dollars tripod support from O-like.com or ebay.

In essence you can use any 405/445/638nm as a source. This one would be the most visible but limited to about 120s of gunning. If you want max length run duration, get those bigger 445nm nearly 3W lasers, but wait….your eyes can’t focus on blue light properly over a big distance…so strike that out.

http://lazerer.com/Green_Laser_Pointer/lazerer_lzsk_532nm_400mW_high%20power_DPSS_green_lase_pointer

Something like this (of coz in this vid they want it to be focused as small as possible at a huge distance…sort of).

http://www.youtube.com/watch?v=EzY30Ah8bKY

Additional fun

http://www.youtube.com/watch?v=13aNFKO4wBI

Hmmm… I do have a large 3ftX3ft Fresnel lens… would that work?

[willie]

@Shadowww

@willie

My green PT120 has a large rectangle projection with a aspheric lens. Stainless shim with a bat on the led lens would produce he desired results with an aspherical lens. This led is capable of 3500+ lumen. But can you live with a green bat?

Well, can’t the green PT120 be replaced with white CBT-90? :Р

Apples and limes…. PT120 is a rectangle (16x9 ratio) for HD television applications and would give a wider profile than the lower power lower lumen lumen white square CBT-90. The PT121 ratio is 4x3. Both PTs run @ 36A max. Bat is wider than tall.

[Rufusbduck]

My best bs answer: A point source works because it creates a shadow with defined edges. For a flashlight beam to do this the image has to be located far enough from the source that the source behaves as a point. The greater the separation, the sharper the image. A multi emitter light would need a greater separation still.