Moplar_guy is almost 100% correct. I do know of one exception however. Kodak used to make a flash gun with the name of Kodalight IV Flasholder. It has a 4 inch reflector and will take a bulb of the #5 or Press 25 size just as easily as an M2, M3, M5 or M25 bulb. However it was a pin connector for Kodak cameras, not a near universal hot shoe mount. Perhaps Kodak (or someone else) made a version that would connect to a PC socket or hot shoe. I just have never seen one like that.
As Moplar_guy pointed out smaller bulbs worked best with a smaller reflector and larger ones with a larger reflector. That is likely why Kodak picked a mid point 4 inch reflector for this dual use flash gun.
Last edited by brianmquinn; 03-31-2011 at 08:57 PM. Click to view previous post history.