Topic: Mains powered flash - slightly off topic

[Nigel]

I hope someone can help I'm working on a project, with a friend who runs a gallery, to build a photobooth to run along side an  exhibition next year of portraits of people wearing masks (it's a long story, more later).

I've got most of the details worked out but as I'm basically paying for the thing (yes it was my stupid idea) I need a cheap mains powered flash. I've tried looking on ebay but because I don't have a model to look for it's real needle in the haystack stuff. The cheapest I've been able to find is this which is called an Opus OPL-M40.

But it's still $44 + shipping and I can't find it for sale in the UK.

Would anyone know the model of an old flash that can be mains powered I can search for on ebay? or a cheaper alternative to the Opus. Any help would be really appreciated. I'm hoping to start working on this over the holiday.


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[Pete_R]

I think you need to search for 'Portaflash'. I think the one you've shown is an old model. They were sold by Jessops. Don't know if they still do them.

[Francois]

Or you can hack an old portable flash unit like I did. All you need is a small power supply (4 batteries=6 volts, 2 batteries=3 volts). You could even simply file the battery door to let the wire out and use a set of dowels cut to the right size with screws as contacts.

[Nigel]

Francois - I did wonder if I could do that, electrics isn't really my strong point.

I have an old Chinon flash I won with a camera I bought on ebay, which takes 4 x AA cells. Could I be really cheeky and ask that sometime you could may be do a really simple sketch showing what I need to do? There's no rush anytime would be great it would be a big help then I can just by a cheap transformer as you say.

[Francois]

Here are a few pictures from an old electronics magazine.

You just use a voltmeter to make sure you have your polarities correct and you should be in business.

For the power supply, when you look at the label, you will need 6 volts DC. The higher the number of amps, the faster the flash will charge. We usually end up with a bunch of wall cube chargers lying somewhere in the basement that used to belong to cordless phones and such. They probably would do the job.

As for the wire to use, just about anything thick enough should do.
The jack attached to the dowels is optional. You could just solder both the power supply wires directly to the screws. Though I would recommend the extension wires as these are going to be bigger than the tiny power supply wires...

If you need more detail, feel free to ask.

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[Skorj]

Some further reading on flash hacking can be found here:

http://blog.juergenspecht.com/2009/the-super-flash-gun/

A few embedded links can also be followed for related subjects too. Please ignore any references to me, as they are all lies. Skj.

[Francois]

WTF was that thing? It's even more monstrous as the things I build... should be illegal 

[Nigel]

Thanks guys that's great, I'm going to do that. Once the booth is built I'll post some pictures.

Nigel

[Francois]

Is the boot going to be film or digital?
Are the people going to take the picture themselves or will you be waiting in the wings to press the button?

I'm curious as I've been wanting to build one for ages but never did...

(I love photobooths... too bad they're so expensive by now.)

[Nigel]

The booth with be digital (unfortunately), as we want to be able to give people a print to take away with them. I've scored an old laptop from work, with a broken screen, I can do tethered shooting on the that with my Canon dslr. The subject will fire the button via a remote, with the camera on self timer it'll give them 5 secs to pose. The laptop in the booth will be networked to the gallery iMac where we can print the portraits - one for gallery, one for the subject.

The whole thing is a project that'll, hopefully, get some local interest and bring in people who wouldn't normally go to the gallery.

As I'm writing I wonder whether we could get the images posted to an online gallery in real time? I'll have to think about that.

I'm hoping to get the booth mechanism made up over the Christmas holiday and the booth itself early in the new year. The weekend itself is mid-March (if you're in South-London).

[Francois]

If you're using a DSLR, you need to do a check on the old flash first.
The thing is some older flashes will send up to 300 volts to the camera... this will fry most circuits for good.

The easiest thing is to put batteries in the flash and use a voltmeter to check how much juice comes off the hotshoe. I read on Instructables that under 3 volts is OK. If the voltage is higher, then you need to add a circuit to lower the voltage (or get a Wein SafeSync plug). The DIY solution is much cheaper to do and can be assembled as a "bundle" without using circuit board.

[Nigel]

Francois - i had read that somewhere but thanks for the tip. I thought I'd connect it via a sync lead,  I assume in that case I should have no problems - should I?

[Francois]

If there's a wire, there can be voltage going through it no matter how it's plugged...

[Nigel]

OK, point taken, I'll check it. Once again thanks for your help.

Nigel

[Francois]

No problem.
If you decide you need a safe sync device and want to build it yourself, I found a great plan on Instructables (which I built for my old Nikon F601... I take very good care of her) so I can give you tips on the build.