Need Help/Advice on Homemade BRIGHT FLASH

As some of you may know, I do a good bit of caving, and like to take photos of them.
I have been wanting to make my own flash system for quite a while now.

Have any of you tried making your own before?
I am wanting to know what it is gonna take, as far as $$$ and parts.

I cant seem to find the website now,
it was mega something,
anyway, they had ones that were around 70,000 lumens ! /ubbthreads/images/graemlins/ooo.gif

I dont think anything that bright is within my range,
but I would like to see what I can come up with.

I dont even know where to begin, as far as the circuit, capasitors etc to use.

Thanks for the help

~John

Heres that megga site i was talking about...

http://www.meggaflash.com/

Im gonna stop looking there now, since thats gonna be out of my $ range /ubbthreads/images/graemlins/icon15.gif

But I still want to make one ! /ubbthreads/images/graemlins/grin.gif

Making the flash isn't hard, buying the bulbs can be!

The MeggaFlash 330 is about $50 a pop if I remember right!

Good luck!

Bill

How bright can I get with a reusable setup?
Like the external flashes for 35mm cams.

I dont expect to get near those kinda of output, but better than what I have.
I have a pretty nice 35mm flash that we use sometimes, but it just doesnt reeach enough.

Big "potato masher" handle-mount (as opposed to hot-shoe mounted) flash units (Metz, etc) top out at about GN (guide number) 150-200. If you don't know or forgot what the GN system is for flash calculations,

(distance) x (aperature) = (guide number) at a specified ISO/ASA film speed and specified unit of distance and a specified lens length(angle of coverage)

Let's say you have a flash unit with a GN=200 (feet) at ISO/ASA 100 for a 50mm lens and the object of your photographic interest is 50 feet away, then you would use f/4 for your aperature and you should have the correct exposure.

For caving pics, you might want to set the camera on a tripod and use the "Bulb" setting or maybe TTL automatic and "paint" the cave/scene with multiple pops from a handheld flash unit. Look up "painting with light" in the context of flash photography.

MoonRise,

I have been "Painting" pics for a long time.
as can be seen in this thread...
Sinks of Gandy Caving Trip

I have also used the 35mm flash, that normally mounts to 35mm cams,
to flash the scene by hand multiple times,
and while that works fairly well,
I still have to walk around too much.
Which you sometimes dont have quite enough time to do.

Plus you end up being a ghost image in the shot.

I need a flash like I have, but that can reach further, brighter.

We did do some, with the flash doing the close stuff,
and painting the far away stuff with lights, which helps.

Thanks for the equation tips, I have never used that.
I just do what looks good, and take a few diff pics with diff settings.

~John

John,

If you're tired of painting the scene with a battery-powered hand-held flash, the next step up is to haul a full studio flash unit with you. How about an equivalent GN of 640 (feet, ISO 100)? That's f/5.6 at a subject 114 feetaway with ISO 100 media. That's the approximate rating of a 3200 W-s WhiteLightning X3200 unit with an 11-inch reflector. Rated at 56,000 Lumen-seconds for a 1/900th second full power flash pulse. For that 1/900th second flash pulse, there are 50,400,000 lumens (average) available!

It's only 7.1 pounds with the 7 inch reflector. But you'll need to haul a source of 120 V AC power with you. Like a generator, or some 12V batteries and a hefty inverter.

Check out White Lightning X3200 flash unit page

You already had the page for www.meggaflash.com The PF330 flashbulb is listed as 140,000 Lumen-seconds output, but that's over a 1.75 second duration. Still, 80,000 lumens (average) over that 1.75 seconds is not a shabby amount of light.

Seriously, TANSTAAFL. If you want output power, you need input power to fuel it. Along with the weight and cost that goes along with it. Either big flashbulbs like the Meggaflash ones, or a big electronic flash unit. If you are trying to light up Fenway Park, or the Houston AstroDome, or a big cave, it takes some serious light power. A 5mm Nichia powered by a coin cell isn't going to do to well. /ubbthreads/images/graemlins/grin.gif

Mike,

Some really nice stuff there!

These are alittle large for my needs though, especially in size.
The caves I am in have large rooms, but you also have to go through some very tight spots to get there.
Theres no way your taking a generator in a cave! /ubbthreads/images/graemlins/icon15.gif

I need something about 3 to 5 times brighter than my external 35mm flash.
I think that would be just enough, I could use more, but its just not within my price range, or size range.

I basically wanted to find a nice flash bulb (reusable) and make my own batt pack and capasitor for it. /ubbthreads/images/graemlins/tongue.gif

~John