Flashbulb to electronic conversion?

[Greg_E]

OK, I know I've seen a company advertising that they will convert your old flashbulb flash to an electronic flash, but I can't find them anywhere now.

Or anyone have any info on converting a flashbulb to electronic flash? I have a couple of Rolleiflash units that I want to change for use with another project. Would like to get a nice variable power thyrister type built, nicer would be to have a photo sensor for "automatic" exposure. Of course it must look as close to stock as possible which means I will probably have to go with some kind of advance battery technology, probably Lipoly since they are small, powerful, and easily obtained.

Anyone able to point me to some guides that might get me started? Working on electronics is not a problem, so if I have to make major changes I should be able to get them done.

 

[Steve Smith]

If I was doing this I would try to fit the circuit from a Vivitar 285 in there. If there is not enough room, Vivitar (and others) made some smaller auto thyristor models.


Steve.

 

[John Koehrer]

I would think the greater challenge would be changing the synch speed at the camera. Depends on the combination of course, I'm imagining a Speed Graphic or something along those lines.

 

[2F/2F]

"Of course it must look as close to stock as possible..."

Why must it?

Why "of course"?

 

[Greg_E]

Because it must look as close to stock as possible. It will be going on my Rolleicord V which has M,X, and V flash sync.

I was thinking of 283/285 guts but the thing that is really important is the flash tube. I don't have much knowledge about that part. Building a new circuit board for the componets, not so hard. Dealing with the flash tube is the part I don't know about. The last time I saw a flash bulb was when I was a child, so I don't know where the filament needs to be to get the correct pattern of the the reflector assembly. Also I do know that most of the Zenon tubes need some sort of correction to bring them down to 5600K which is something I haven't found a way to do that will allow the flash to look original.

So yes the "vintage" look is important to the whole package, but I want modern function. If the look wasn't important I would just grab a 283/285 and slap it on a short handle and go. Or maybe whatever it was that Arigram recently teamed to his 'flex.

 

[Ian Grant]

I think the adverts you've seen where here on APUG, at the bottom of the(there was a url link here which no longer exists), one of the block adverts.

Unfortunately I cleared my browser history or I could easily have searched & found it for you.

Ian

 

[Greg_E]

Yes I'm fairly certain it was one of the forum ads, but after looking at the sponsors page one than once, I still can't find it.

 

[JBrunner]

I'm not positive, but I think I recall that they were based in Hawaii.

 

[John Koehrer]

GregE.
Do you have the flash you want to use as a housing yet? That may make a difference. Honeywell used to have a potato masher style Strobonar that was used by a lot of pros. If you're thinking of the Graflex type I don't know that they were used so much with the Rollei. If it's a smaller fan type flash you may need something smaller than the 283 more like the 252 or it's like.
Anyway, the color correction is built into the flash tube so it's something you really don't need to concern yourself with.
Stripping out a 283/5 shouldn't be too much of a challenge, it may be possible just to split the board & jumper the connections.

 

[Greg_E]

This is the flash that I want to end up with, except I don't have the lens mount for it. The threaded part is 3/8-16 to give you an idea of scale, I forget the diameter of the reflector as I just received them Friday. It originally used a 22.5 volt battery that is square and the size of an AA cell. I will probably have to build a custom handle to mount it to the bottom of the camera, and that can probably hold the power source.

I also have a newer style that did not use a battery and does not have the coil up cord. This will probably be the prototype housing since the one with the coil up cord has more character.

 

[Greg_E]

OK, so I started looking around for examples of other modern flashes that use a similar design. SO does anyone know how many watt seconds I should be shooting for to match what I would get from the flash bulbs for this flash?

Here is an example of one of the modern flashes, and it takes a tube that I may be able to fit in the Rollei housing:
http://www.bhphotovideo.com/c/product/121956-REG/Norman_812220_LH2_UV_Lamphead.html
spare lamps are only $44 so after I find the electronics to drive it, I might be in business. Going to keep looking for other modern flashes to see if I can find a camera mounted design with similar reflectors. I know that you used to be able to buy so flashes that had an open reflector head like the Rolleiflash, I just need to track this info down again.

 

[Greg_E]

The flash I was thinking of was from the pre digital age when you actually had to know how to measure or calculate the flash output, and is now long gone. It was the Sunpak 120J and I'm almost certain there was Metz that also had the same type of head.

 

[2F/2F]

You won't find a small electronic flash that matches a GE#5 bulb for the GNs it gives you...and that's a relatively small flashbulb (!). As far as Ws, I do not know.

I would just forget about how you look, and shoot. This is incredibly vain and pointless. Attach a $90 Sunpak 383 and call it good.

 

[Greg_E]

GE#5, thanks. I'll do some research on that bulb and see what I can find. That said I think the tube for the 120J is going to be what I base this on. Hopefully I can get the electronics cheap and start working this into a functional device. More important is the socket for the tube, and hopefully I can get a couple from ToCAD America. Then I'll either find a schematic to build, or pull some other flash apart for the design.

Vain and pointless? I disagree. Nostalgic and trivial maybe, but not vain and pointless. It would allow bare bulb, open reflector, softbox, and very directional snoot use all from a single head just by changing the attachment on the front. That and all of the modern flashes with the fresnel lens over the front are going to give a seriously different look than the round reflector from what I want to build.

 

[Greg_E]

BTW, last night I sent an email to ToCAD (Sunpak) asking about the socket and a few parts, and I explained what I wanted to do. So a get a response this morning that the socket is $15 and that because the electronics are complex, that it would be best to send the repair manual (which came attached). A very refreshing change from what I expected. I may now be able to design a circuit board that will fit in the space available, as well as buy the socket and flash tube to make this happen. I may still get a less complex flash to supply the electronics for now, but I'm pretty set on the flash tube.

 

[John Koehrer]

Greg_E.
I certainly understand the idea of the nostalgic look of the combination. One man's treasure etc.
There just may be enough room in the Rollei flash unit to squeeze the electronics from a 283/5. If you just want the full output of the flash you can probably eliminate the automatic exposure circuitry from the board to miniaturize it. A lot of what's in the 283 isn't needed if that's all you need but, you would lose the quicker recycle of the thyristor circuit. Another flash that's similar in size would be Metz 32 series.
You're not going to match the output of a #5 bulb with a compact electronic flash. Actually I don't believe the handle mount units came close either.
Part of this may be burn time of the bulbs which was much longer duration than electronic flash.

 

[Greg_E]

Thanks. Not too concerned with ultimate output power as I think I'll get plenty with the 150 guide number basis of the Sunpak. So if I can hit that I should be fine. Most of the flash work I've done in the past was with a 283, so anything with more power would be fine. Wish I still had some of my old stuff, would make a nice donor right now. Have to see if I can find something with a non-functional flash tube that I can use for cheap parts.

 

[Ralph Javins]

Good morning;

Edmund Scientific Company, Halted Specialties, and other surplus, specialty, and odd ball electronics parts houses (look also in the magazine NUTS & VOLTS) will have flash tubes that you might be able to adapt to your application. The FT-118 is quite common. They will have some capacitors and other parts also. Put the tube in about the center of the dish near where the globe of the flashbulb would reside. You are looking for a fairly wide light pattern anyway, so do not worry too much about being in the exact focal point of your reflector. The flash tube and the bulb both will be around the focal point. The main thing will be lighting uniformity. Try it and see how it comes out. Most likely, it will be fine.

This will be an awful lot of work to make the conversion. Please let us know how it works.

Enjoy;

Ralph Javins

 

[Greg_E]

Thanks. I've pretty much decided that the above mentioned tube is the one, the Sunpak has the same/similar reflector so that will make things easier. I now have 3 of these rolleiflash units sitting here waiting, with about 5 other projects in line ahead of them.

I think this is something that can be done, may not be thyrister but it should at least work at full pop. Coming up with the space for the power may be difficult, I may have to go with a very small battery and only a few pops before it is dead. But it will be cool when it is converted. I'm thinking of some 7.4 volt 450mah Lithium Polymer packs that are used in radio control models since I think they will fit with a minimal full pop circuit board. The output will of course be determined by the amount of storage I can get from the cap, so those are the two biggest factors in making it all fit inside the triangular housing. I may have to machine a new larger triangular housing to hold everything leading back to project #1, get my bench top milling machine set up and able to start cutting. Waiting for the last few pieces for the milling system to arrive.

 

[John Koehrer]

The way the Lipo batteries handle discharging, you cold go to something like a Quantum battery 1. It's a 6V rechargeable belt or over the shoulder pack with a number of cable available. Using that you should be able to make the flash self contained with only a plug being added for the Quantum. Likely easier than making a new housing. In the days of that outfit,Honneywell may have just been introducing theior electronic flash units with the ots battery pack so it wouldn't be to much out of character.

 

[Rolleiflexible]

I'm reviving this thread because my wife Melanie
wants a flash for her Rolleiflex. Has anyone since
this thread began tried to convert a Rolleiflash?
Or is anyone aware of the folks who have made
or are making the conversions?