Flash

[Rekusu]

What ho one and all,

I have a 240v photo-flash unit that can power up to 4 heads, but I only have three.

The unit has a switch that allows full or 1/4 power. with one head plugged in, I either have 100% or 25% of the output, so can control within reason the power of the light source. With two heads plugged in, the output is halved.

Sometimes, I don't want to use three heads but do want to reduce the output. The easy option is to move the light further way, but that changes the light to more of a point source.

The attached image is the output plug (an old one before I rewired the flash heads). Is there a way to wire some plugs that will allow me to reduce the output but not actually have a light attached? ie. make the power pack think there are three lights attached when there are only two.

Thanks and toodle pip

 

[AdrianUK]

Maybe....

But we would need far more information.

What you have shown is is the inside of a BULGIN PX0551 8 pin connector. Unfortunately just showing us that wiring means nothing - that connector has been used on many many things over the years - its not unique to Photoflash units. At one time it was a very common connector on disco sound-to-light units - pretty much every mobile DJ in the Country would have had half a dozen of them.

Can you give us model details of the Photo-flash units you have? It might be posssible to find a manual on 'tinternet .....

 

[chivers67]

Without knowing more about how the units are wired I think the best option would be to put some kind of Neutral density filter in front of the flash head to reduce the intensity of the flash output.

 

[Robin0577]

Without knowing more about how the units are wired I think the best option would be to put some kind of Neutral density filter in front of the flash head to reduce the intensity of the flash output.

Absolutely agree! Large photo flash units are extremely dangerous to tinker with even when you have all the information.

ND filter much simpler.

0.3ND = 1 F stop
0.6ND = 2 F stops
0.9ND = 3 F stops... etc..

https://www.10outof10.co.uk/acatalog/E-Colour---210--.6-Neutral-Density--8113.html#SID=554

 

[winston1]

What does “toddle pip” mean?

 

[oldbutnotdead]

Are these xenon flash tubes or tungsten photofloods? If they are xenon then be careful, there could be some very scary voltages in those cables. If tungsten then there is likely some series/parallel switching going on, more detail needed.
8 pin Bulgins, PAR38s with baking foil on the back of the plywood housing and those cheap 4 channel sound to light boxes- happy days

 

[mattylad]

What does “toddle pip” mean?

It was "toodle pip" not "toddle pip", and thats geezer talk for goodbye.
https://www.urbandictionary.com/define.php?term=toodle pip

 

[winston1]

Thanks.

 

[Rekusu]

Toodle pip;"The use as hello/goodbye was first recorded in 1906 in the Marvel, a boys' comic and would become especially popular among the characters of the comic novelist P.G. Wodehouse."

Thanks for the replies. The attached is a photo of the flash pack, a Courtenay Photon 800. Probably around 40 years (or more) old. When I wanted to use it last year, after many years of non-use, the insulation around the cables to the heads (most likely, original) had dried out and flaked off in my hands. So I replaced the cable. At the same time, I replaced the various lengths of wire inside each head as that had also given up. Due to lack of use, the capacitors were no longer doing their job but after a lot of research, i found the best way to re-format them, and although not perfect, after around 15 mins of on-time, they do fully charge and discharge as required. When researching the capacitors, I did open the unit and all the wiring (insulation), unlike that in the heads, was is good condition.

Unable to find anything on the web relating to this unit but there are plenty of Courtenay flash heads around. Mine look like this, probably similar vintage, (https://www.ebay.co.uk/itm/383585849335?hash=item594f7f8ff7:g:jkIAAOSwMNhe4k3A) but do not have all the options as they plug into the flash unit.

Essentially, there are only four active wires plus earth. Two are for the modelling light (tungsten) and two for the xeon flash tube.

Just wondering if it is possible to wire a 'something' to another plug, probably across the xeon wires, that will make the pack think it has three of four heads in use when in fact, there are only two. This would give a degree more power flexibility.

Agreed that ND is probably best, but when using a soft-box, it is not so easy. My soft-box is only around 50cms square and for nice portrait modelling, works best when closer to the subject; moving it further away and it become more of a point source.

Recently when taking some portraits, I wanted to reduce the output and hence open the lens for a more out-of-focus background. In the days of film, I was using 50 ASA so not a problem but my digital Nikon only goes as low as 200 ASA.

As for the dangers, yes, the capacitors can hold residual charge after turned off but the heads have no electronic parts; just a modelling light on/off.

Thanks and toodle pip!!

 

[ericmark]

I found my flash gun was suck it and see, there was a sensor mounted on camera which should reduce the energy once the sensor had seen enough light, I had a flash repeater under the camera, and I would have thought if I set the distance and experimented until got the picture I wanted, if I then did not touch the focus but moved camera further of closer to item, then should get same result.

However this was not the case, my problem was carrying enough batteries, main reason for flash was to freeze motion, so wanted it dark outside.

I moved to using LED lights unless wanting to freeze motion. The studio at collage was also rather hit and miss, I tried to set it up, but not impressed with results, the big problem was high voltage, the hot shoe on my old film Pentax was designed for around 250 volt which was a standard with flash guns, but both my DSLR's were rated at 12 volt, so only one of my flash guns could be used on the DSLR cameras, could use the others with the slave, but not direct.

Many studio lights are also too high of a voltage, and often only way to use them was to have the cameras built in flash trigger them, and the built in flash would reduce output when studio flashes fired.

The unit shown looks very old and I would not connect it to my DSLR cameras.

 

[Rekusu]

Familiar with the trigger voltage issue but that was not my question.

However, some internet searching for Nikon D300 and I found this which was in reply to a similar question, from Nikon. "As long as the flash's sync voltage is less than 250 volts it will not damage the camera and should work fine" Seem to recall testing the pack trigger voltage and I think it is around 28v.

I do have a Chinese wireless trigger thing but its operation is somewhat flaky.

 

[chivers67]

My guess would be to find somekind of resistor that has the same amount of resistance as one of your flash heads & incorporate that in some kind of enclosure. Have you or can you get another plug for the courtney unit and wire the resistor to that which a switxch and fuse to be on the safe side? Is the voltage output high the supplies the flash heads ?

 

[Rekusu]

Yes, the plugs are still available; as mentioned above, it's a BULGIN PX0551 8 pin connector.

Don't know what the flash voltage is but would assume that it is high. As the plug would not have to actually power anything,I guess if I found a suitable resistor, it bout be fitted within the plug housing; no additional wire needed? It would only be connecting the two xeon tube terminals?

 

[chivers67]

Yes, a small resistor would probably fit inside the plug and maybe bridge two terminals maybe use a little heat shrink/sleeving on it to insulate the wire from touching anything else

 

[Rekusu]

What do I need to understand about the resistor size?