Flashgun questions

[Brian Masney]

Hi,
I am fairly new to using Flashbulbs for cave photography. I have two Honeywell flashguns that I use to fire M3 flashbulbs. I also built some small flashguns with a medium screw base for firing #0, #2 and #3 bulbs. Does anyone know of an adapter that I can buy to put the M3 bulb in the medium screw base? Or, does anyone know where I can buy the plug to insert the M3 bulbs?
I've also heard that flashbulbs can be fired underwater. I've also heard that if a bulb gets wet while it is firing, then the glass may explode. I don't want to make a mess in a cave. So my question is if the bulb is submerged in cold water before it is fired, will the glass break whenever it is fired? Or, do you put something around the bulb to catch any glass that may break off? If so, what material to you use?

Brian

[Darklight]

Brian:

I have seen M3 base to Press base (like the Press 25 or GE #5) adapters. Further, I have seen Press 25 base to screw based adapters. So, those two together will do what you want. I've not seen an M3 to screw base adapter (or I'd have bought one!). Look around on eBay for these adapters, or an old old camera shop.

You can fire bulbs underwater, but if laquer coated, I don't think I'd worry too much about disaster. Still, some cave photographers construct a water tight container (a plastic jar with lid, with a bulb base attached inside; wire extending to your gun). This can be used with nice results. I think Bob Biddix does this. Or was it Tim Curtis? Google them.

My bulb site:

http://www.darklightimagery.net/flashbulbs.html

[Evan G]

Or was it Tim Curtis?

Here is the link to Tim Curtis website:

http://www.pbase.com/cavertim

Also Brian, Tim is on Flickr:

http://www.flickr.com/photos/49782418@N00/

[wendy]

Or was it Tim Curtis?

Here is the link to Tim Curtis website:

http://www.pbase.com/cavertim

Also Brian, Tim is on Flickr:

http://www.flickr.com/photos/49782418@N00/

cool website he has, i had always wondered who took that surefire light magazine ad photo, now i know

[pj]

I've fired numerous bulbs underwater by constructing my own flash gun systems, the classic battery/capacitor/firing switch. I made the bulb socket from an automotive bulb holder which is the same size as #5 or Press 25 bulbs. In addition, I attached a long speaker between the socket and the case containing the battery/capacitor configuration. I also drilled a hole through the side of the socket and using a slip ring, attached a one ounce lead weight to it. Thus the bulb sinks beneath the water to whatever depth you want rather than floating on the surface. Works great! I've never had a bulb explode underwater as the lacquer prevents it.

Peter
Shot in the Dark Cave Photography

[Dave Bunnell]

Regarding bulbs exploding:

I guess I've never seen one explode underwater either. However, bulbs that have gotten wet and sat around wet for awhile often do explode. I suspect it has to do with the plastic coating softening up over time, since plastics can absorb water. But a dry bulb just stuck into water wouldn't have this issue.

[rcoomer]

Wet M3 bulbs do explode, just ask Eric from when we we're shooting the B+W salon winner. They sound like a shotgun going off and are very startling. They generally don't explode when under water though.

I have been experimented with making my own underwater gun, but haven't worked out all the kinks. I found a taillight socket held the base too tight, so once the bulb shattered within the coating, it collapse when enough force was applied to remove it from the socket.

I went to an m3 bulb in a bayonet adapter to get around that problem. At the moment I have some wiring issues causing problems and needing to add in extra weight. I need to use a solder gun to make better connections.