I have this cool dish shaped flash thingy. It's from before the dinosaurs so it takes flash bulbs that burn up in one go. I'm hoping I could modify it to a pure electric flash.

I though some replacement bulb must exist but I had no luck finding them.

enter image description here

  • \$\begingroup\$ For modern versions of the 'real thing', have a look at movie props suppliers. I don't know that particular bulb type but I worked on several series of The Crown where they were going through bayonet-style flash bulbs by the pallette-load. The flash units had all been modified to take 4 modern D-cells. \$\endgroup\$
    – Tetsujin
    Commented Feb 12, 2021 at 12:21
  • \$\begingroup\$ I'm no photography expert but I'm certain it can be modified. Whether you can do it without accidentally destroying anything is another question. \$\endgroup\$ Commented Feb 15, 2021 at 16:16
  • \$\begingroup\$ One reason why those aren't popular any more: When the flash "burns" (yes, it's rather slow process) the glass of the bulb literally melts, and as glass isn't actually glowing when hot, you can severely burn your fingers or anything else when you "eject" the used bulb. \$\endgroup\$
    – U. Windl
    Commented Nov 12, 2021 at 12:59

4 Answers 4


Original flash bulbs aren't all that rare -- last time I looked, they were pretty easy to find on eBay (maybe Etsy too, these days). There are several kinds, however; the bayonet style (base like an old style incandescent tail light bulb), the push-in "M" style, and the "AG" ("all glass") type with no applied metal base. I can't tell for certain from the photo which kind your Ikoblitz unit takes.

I'm not aware of any electronic flash units that plug into a flash bulb socket like the one in that reflector, however -- the first of those that I recall were for FlipFlash or Flashbar (late Kodak Pocket Instamatic and Polaroid SX-70 family, respectively); instead, there were and are many different electronic flashes that would mount in the same "hot shoe" that Ikoblitz does -- an accessory shoe on the camera with contacts wired to the sync system in the camera shutter. Even current manufacture add-on flashes made for DSLRs should work with a hot shoe on (as an extreme example) late 1940s vintage leaf shutters with PC sync socket (though you'd need a shoe adapter that connects to that socket in that case).

The reason electronic flash won't work with bulb sockets is voltage -- electronic flash uses between 300 and 450 volts, while bulbs need between 1.5 and about 21 volts. There isn't enough power in a bulb flash to fire a xenon flash tube, but most electronic flashes use a simple external contact switch to fire (some with protection against high voltage on the contacts, older ones often without).

  • \$\begingroup\$ Just to expand a little bit. The electronic flash is a xenon gas filled tube that is fired by ionizing the gas with a high voltage kicker allowing it to conduct the main power from a high density capacitor which supplies the energy to make the light. Flash Bulbs consist of a nothing more than very fine Aluminum Wires . A simple battery heats a piece of the wire up enough to burn, setting the rest of the aluminum burning. \$\endgroup\$ Commented Feb 13, 2021 at 22:53
  • \$\begingroup\$ @user10216038 Some are magnesium instead of aluminum. \$\endgroup\$
    – Michael C
    Commented Feb 14, 2021 at 20:05
  • \$\begingroup\$ @Michael C - Magnesium has a lower exothermic reaction (Heat & Light) and costs much more than Aluminum. Why would anyone manufacture an inferior product that costs much more intentionally? \$\endgroup\$ Commented Feb 14, 2021 at 23:16
  • \$\begingroup\$ @Michael C - camerapedia.fandom.com/wiki/Flashbulbs . The first actual flashbulb was the Vacu-Blitz, made in 1929 by the German company Hauff-Leonar AG on basis of a patent from Johannes Ostermeier. This patent describes the application of ultra-thin alumnium foil (0,5µ) in a glass bulb with a low pressure oxygen atmosphere. It was the first flash bulb design, which could be reproduced on a larger industrial scale. \$\endgroup\$ Commented Feb 15, 2021 at 4:33
  • \$\begingroup\$ @user10216038 Magnesium was used in most early flashbulbs for whatever reason(s). As to why they used magnesium, perhaps it was because the makers of magnesium flash powder, which preceded self-contained flash bulbs, realized their flash powder business was about to take a nose dive and they started making bulbs too. In addition to magnesium, the bulbs were filled with oxygen rather than natural air. \$\endgroup\$
    – Michael C
    Commented Feb 15, 2021 at 21:59

The flash is a german make produced by Zeiss. Replacement bulbs are called RF1B Blitzlampen (translates to flash bulbs). You may have luck with that as a search string. Form time to time, the tend to show up on ebay, or a photo store sells them as vintage stuff for around 15 Euro/Dollars a pack.

There is also the german manual page here: https://www.kameramuseum.de/blitz/zeiss-ikon/ikoblitz-6/ikoblitz-6-anleit.html which states, that you can also use bulbs of the type AG1, but should then use the clear part of the cover of the flash over the bulb to protect from potential burst of the bulb.

Also, the B at the end of some bulbs seems to stand for blue hue of the light.

AG1 Flash Bulb

RF1B Flash Bulbs


The basic reason you haven't found simple "plug and play" electronic bulbs that would work in a non-modified flash made for single use bulbs is that it's not really feasible.

The energy for single use flash bulbs is contained in the chemicals inside the bulb, not in the small amount of current applied to them to initiate a chemical reaction that releases the energy stored in the chemicals.

For an electronic flash tube, much more voltage is required than what is provided to chemical flash bulbs. In order to use a reusable gas filled tube with vintage pieces designed to be used with disposable flash bulbs would require essentially building a modern flash's electronics inside the vintage housing.


If you take a look at the guide number diagram, you get a guide number of 20m at 25ASA which corresponds to a guide number of 40m at about ISO100, at very wide angle illumination. The reflector cannot really hold a candle to a more modern flash tube reflector. An equivalent electronic flash would have significant energy to dispose of: the Metz hammerhead flashes are specified as having 45m guide number at ISO100 for 35mm illumination angle (narrower than what you appear to have there). They store about 70J of energy if I remember correctly. A typical strong cattle fence has about 3J of energy and comparable voltage. There has been some stupid trend in Japan of children shocking others with parts from old flashes, actually causing some fatalities.

The combination of the metal reflector and the contacts in the sockets is not at all proof against touch. In a hammerhead flash, a significant part of the handle is filled with the flash capacitor. In a cobrahead flash, the tilt joint is typically filled with capacitor.

Getting a complete electronic flash with capacitor and charging circuitry in the place of the bulb while retaining a comparable power to the chemical flash bulbs would be infeasible. Putting the charging circuitry elsewhere and only placing the flash tube there would mean that lethal voltage would be running around open metal parts.

In short, bad idea. If you want a show prop, invest in the original bulbs. They are set off using voltage that is not dangerous to humans.

  • \$\begingroup\$ It's not voltage that is dangerous to humans, it is total current (amperage). In high school physics class we had a Van de Graaff generator that put out several hundreds of KVolts! It was safe to touch as long as you didn't mind your hair standing on end. But the total current is very low as the resistance was practically zero. \$\endgroup\$
    – Michael C
    Commented Feb 15, 2021 at 23:42
  • \$\begingroup\$ Opps! I just killed someone (theoretically). The reason Van de Graaff generators are harmless when used properly to make one's hair stand on end is because the resistance is almost infinite, not near zero. \$\endgroup\$
    – Michael C
    Commented Feb 15, 2021 at 23:56
  • \$\begingroup\$ @MichaelC You did read the part about 70J of energy being stored in the flash capacitor? Currents of heart-stopping strengths are sustained long enough to actually do this, and the voltage is sufficient to drive them through a human body at that strength. There is actually enough current available to leave a serious pock in a screwdriver you use for discharging the capacitor. This isn't low-energy static electricity that gives you a bristle and maybe a jolt and haha. Repairing electronic flashes is not a joke and the capacitors can sustain voltage a long time after switch-off. \$\endgroup\$
    – user95069
    Commented Feb 16, 2021 at 0:25
  • \$\begingroup\$ Yes, there's a lot of current inside an electronic flash. It is the amount of current, not the voltage, that makes it harmful to humans. \$\endgroup\$
    – Michael C
    Commented Feb 16, 2021 at 0:49
  • \$\begingroup\$ Without voltage driving the current through the high resistance of human skin, there is no dangerous current. A spanner falling on the contacts of a truck battery will melt because of the high current the battery is able to deliver, yet a human is not in any danger from touching the electrodes (at least when not doing it concurrently with a melting spanner). \$\endgroup\$
    – user95069
    Commented Feb 16, 2021 at 1:44

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