Converting Graflex 3 cell flash into electronic bare bulb flash

[Jackle]

[TLDR: Does anyone have any experience converting a graflex 2/3 cell into a
Hi,
With flashbulbs dead, I'm wondering if anyone has any experience converting an old 2 cell flash into a bare bulb flash. I'm thinking of something like the Witstro AD-360 type flashes. Vintage handle flashes are too nice and too beautiful to be relegated to just fancy handles and mere museum pieces (or suffer the fate of being made into another awful light sabre).

At the moment I'm thinking of using an arduino board as the control unit, a Godox PB960 Battery Pack for power, going through the base or the old bi-post connector and a 180v or 360v bulb and various off the self parts. I'm intending to convert a Kalart 3 cell Automatic flash (this is a similar model http://www.collection-appareils.fr/accessoires/images/1323793175.jpg) and use the same duration as a FP flash bulb (although thankfully I can vary it thanks to the ardunio).

If anyone has any circuit diagrams and/or experience with this type of thing, I'll be more than grateful. I have experience with electronics with HAM radio stuff, but I've never really played with making my own flashes etc. Anyway, if it enables an old flash to be usable once again, It'll be worth the effort.

[j.e.simmons]

There used to be a couple of web pages devoted to this, but I'm unable to find them now. They involved disassembling a modern flash and putting the parts inside the old flash handle. I'd be interested in instructions on doing this, too.

[wombat2go]

(Posted before)
The picture shows my approach to the conversion, by adding a small electronic flash in to the existing reflector.

[Tin Can]

I'm in, as the kids say! I would like to utilize the reflector.

[Doug Herta]

Are flashbulbs dead? I purchase them by the case from ebay and use them with my Graflex 2 and 3 cell flash handles. The M2, M3B and other miniature base bulbs (with converters) work well in the Graflex flashes.

For a conversion, I think using the flash handle would work: take apart a small flash, put the electronic components in the handle and the flash head on the top. With a 3 cell Graflex handle you could have the electronics/capacitor on the top of the handle and get a couple D-cell converters where you put 2 AA batteries in one D-cell sized unit. Top third inside the handle - flash components. Bottom 2/3 - 4 AA batteries inside D-cell converters. The batteries would be easy to change and you wouldn't have a bunch of external stuff hanging out. Or just use flashbulbs?

[Jackle]

I've not found that many new flashbulbs on ebay (which I can trust anyway) and when I contacted the last EU manufacturer of them, they didn't bother getting back to me. Repurposing another flash might be good- I would probably end up with something like the Supreme Electronic Flash (which had a bare tube). I already have a Hanimex PZ4200 which is quite versatile and useful. That said, a good and powerful bare bulb flash would be quite useful (even without using a Graflex, they make great studio lighting), and works very well with a reflector. I'm not too worried about weight of an extra battery pack, if I was, I wouldn't shoot LF.

[Will Frostmill]

Hmm, I remember seeing a review of a no-name Chinese bare-bulb modern flash unit, maybe about a year ago? I've thought about disassembling one of those and putting it inside the typical handle plus reflector. I recall that the reviewer had concerns about the safety factor or the bare bulb. I would have concerns about my personal safety during the dis-assembly stage, given the power held in those capacitors.

(Also, hi everybody, I'm back after most of a year!)

[Tin Can]

I buy and use case lots of NOS flashbulbs. They work fine.

But a DIY Graflite convesion would also be nice.

[RichSBV]

Simplest method would be to gut a cheap electronic flash and repack the parts into the old flash handle and head.

I don't see why you'd bother with a microcontroller???

Do remember that the flash tube will light with ~300-400 volts DC but will only trigger with ~3000-4000 volts DC. Luckily you can easily buy the 10/1 transformer. But even the 300 volts can do you some serious damage!

Second problem. The duration of an FP bulb?? Have you researched flash durations? To maintain that kind of duration out of an electronic flash tube would take some big, serious capacitors!

A great project and good luck with it. You can find flash circuits all over the web. If you do finish this, please share it!

[Jac@stafford.net]

I've not found that many new flashbulbs on ebay (which I can trust anyway) and when I contacted the last EU manufacturer of them, they didn't bother getting back to me.

Flashbulbs are currently made in Ireland. See their page here. (http://www.meggaflash.com/) Like Randy Moe, I've had very good luck with old flashbulbs.

Back in the day, I used a singer-graflex bare tube like the one shown here (http://mindtab0.tripod.com/photo/strobonar/graflex/globestrobe250.JPG). Inside the tubular body is one big-ass capacitor. The battery pack was marked 520V. In fact it was about 56 9V batteries wired in series. It might be difficult to replicate that today.

FP synch is, of course, not necessary with leaf shutters, so you must be trying to emulate the same with a focal plane shutter. It is done today in HSS units. HSS uses multiple flashes of the tube to synchronize FP shutters at high shutter speeds.

[jbenedict]

Why screw up one of the few flashes that hasn't been appropriated by the Star Wars goons. Sunpak makes a decent flash with bare bulb.

[BrianShaw]

Gosh... first film is dead and now flashbulbs are dead. What next???

[Jac@stafford.net]

Gosh... first film is dead and now flashbulbs are dead. What next???

Old photographers.

I dream of being offered the opportunity to become a ghost to digital photogs.

[LabRat]

Don't go hacking up a small on-camera strobe!!!!

A/ They squeeze a lot of circuitry inside on flexible circuit boards that are nearly impossible to close these units back together correctly again...

B/ The main cap inside is usually uninsulated and usually grounded to the cap case, (and hard to discharge, because it's hard to access the terminals) so you WILL get zapped as you mess around inside... (Even after you thought you discharged it well!!!)

C/ The usually thin, slender, linear flashtube (in most small flashes) is the wrong shape and difficult to get in the right position to focus the light correctly in a standard bulb reflector... (You might come somewhat close using at least a 200w/s flash with a glass enveloped (removable) flash tube...) These tubes are for the carefully designed/engineered reflectors in your flash...

D/ We have gotten spoiled using features like automatic flash output on our on camera strobes, and this will probably be disabled after conversion... So back to changing the f-stop as you change camera to subject distance... (Just like the old daze!!!!)

E/ After all the above, a med/large on-camera (hot shoe mounted) electronic flash does not have nearly the output of a medium sized flashbulb, so using it at the smaller stops you normally shoot at with LF flash, you might need f16, but barely might get f5.6 or f8 out of it... (Again, at least 200w/s would get closer to what you hoped for...)

Better to mount a side mounted (handle) auto flash on it, or something like a Norman 200 or 400B (manual)...

For now, as a test, put a camera bracket/handle with a mounting shoe on your camera, and try out your largest on-camera flash unit with it, and see if you are getting a close to useable light output with it...

Those old flashbulbs put out a whole lotta light!!!!

Steve K

[Tin Can]

OP perhaps check this thread.

http://www.largeformatphotography.info/forum/showthread.php?124154-Flash-Bulbs-Gear-Info-Images-of-Gear-amp-Guide-Number-Data&p=1264035&viewfull=1#post1264035

[Jackle]

Quick update.

The project is going ahead but I've made some changes to how I was originally going about it. I've decided not to mess with the internals of the vintage flash, simply because its very difficult to fit the components (square PCB in a round housing) and it would bee extremely unsafe (an aluminium tube with a large capacitor, being held barehanded etc).

So, what I'm doing is making a holder for the bare bulb (and the trigger circuit) using an old flashbulb base and a 3d printed insert. The charge used to previously ignite the flashbulb will now trigger the flash. Out of that base, a short wire is going to lead to a `flash box', containing the necessary flash components (including the main capacitor and control circuits). I'm going to attach this box under the Graflex bed (I've found some springs used to mount (eating) plates on walls, which are great for allowing the unit to be attached to my LF/Film cameras). The battery is currently planned to attach to the flash box. The advantage of this is that I'm not going to damage the flash, it will be far safer and I have more room to fit in my circuitry.


At this moment, I'm still designing and working out the circuitry. I've set up a breadboard with some of the components and I'm still hashing out some of the details. Its going to take a long time to properly work everything out and I'm only doing this as a personal project. I imagine that things will change significantly as things go on (I've already changed a lot with my circuits). When I've got a bit further with what I'm doing, I'll post an update.

[Will Frostmill]

Fantastic! I can't wait to see what you'll come up with!

[Jac@stafford.net]

I hope you realize that whatever electronic flash you come up with, it will not replicate the quantity or quality of light the original flashbulbs put out. Not even close. It's like using a starter pistol to simulate a cannon.

[Rojobear]

Hello! I ran across your post and am wondering how your project went? I am looking to modify a Leica Ceyoo flash unit as a bare bulb flash and need some help with the electronics. Did you ever complete your schematics? Any help would be greatly appreciated! Thanks,

Heinz