Flash guns and flash bulbs

[Malcgeorge]

I am looking for some out of the way information/knowledge about flash guns and flash bulbs. Essentially I want to photograph, using modern equipement, a vintage camera firing its flash bulb. So what I am looking for is to be able to work out how it would be possible to get synchronisation between the two (vintage and modern). Ironically I can find out the delay, time to peak output and time of peak output for flash bulbs, but I am struggling to find equivalent data for modern flash guns. I know that flash duration is much (much) shorter with a modern electronic flash, but I need to know the sort of delay there is on first curtain use compared with the synch and also on second curtain compared to the sync speed. If I can get this kind of data I can work out how best to set up the modern flashgun/camera combination to capture the vintage flash bulb firing at a point in its cycle and at a distance etc that will not overwhelm and just white out the sensor. Anyone any ideas/knowledge or info that might help?

[stevewe88]

This might be way too simple but.....

I am sure I have read about sound activated triggers for cameras. I can't for the life of me remember where from though so I know it's only half a suggestion, sorry. I am thinking that either the noise of the flash popping or even the noise of the shutter may be enough to trigger the shutter on the modern camera???

Maybe worth a go

[ktuli]

Or how about a lightning trigger? Something like http://www.lightningtrigger.com/? There might be better models out there, but that might do exactly what you're looking for.

- Bill

[Malcgeorge]

I know about light activated triggers as in 'slave flashguns', but what I don't know is how and when they would fire in relation to a flash bulb discharge. I guess I could try, but I have electronic circuitry that could give me the ability to fire the modern flashgun/camera with a set delay between activation of the vintage camera to allow for the delay it has activating its flashbulb and the flash bulb building its light output. It is then a matter of getting the right delay so that when the modern camera is activated it lights the scene and there appears to be something of a flash in the flashbulb of the vintage camera which is part of that scene. Then, of course, it might be a matter of having the shutter of the modern camera closed before the full output of the flashbulb is reached and creates a problem of over exposure/lighting in the modern camera. I suppose the delay might be set to coincide with the fall of of the output of the bulb, but this tends to be steeper than the rise in output and hence timing is a little trickier. Not insurmountable, but just a bit of a problem to get it set right. If I could know the details for the modern flash setting it all up would just be a matter of setting the right delay between the modern and what occurs in the vintage. I imagine that modern flashes fire pretty early in the opening of the shutter on first curtain, but how early are they and how does that change with shutter speed?. Also when are their firing on second curtain towards the end of the opening of the shutter. Anyone know what is typical?

[Malcgeorge]

By trial and error I managed to get a great shot of a model holding a vintage camera with the flash bulb going off.

[sbougon]

By trial and error I managed to get a great shot of a model holding a vintage camera with the flash bulb going off.

Malcolm, please share

[Colin Southern]

I'm confused ... why do you need anything special? Just leave the shutter open long enough to capture the old-time flash going off.

[PhotomanJohn]

I am going to show my age but in the good old days we used 1/30 sec if we needed to get the full output of the flash. Shorter exposure times reduced the light. If it were me, I would start at 1/30 and see what I got. I know the shutters are different and the sync is different but I suspect it will still work.

John

[PhotomanJohn]

Well, I dug out one of my old books and it has tables for both leaf and focal plane shutters and flash bulb drop off with shutter speed. For focal plane shutters the factors are 1 for 1/25 or 1/30, .6 for 1/50 or 1/60, .5 for 1/100 or 1/125, .3 for 1/200 or 1/250, .2 for 1/400 or 1/500 and .15 for 1/1000. Probably more info than you wanted but fun to stroll down memory lane.

John

[Colin Southern]

Grrr.

Stick your modern camera on manual - shutter speed around 1/2 second - aperture as far down as it'll go - ISO as far down as it'll go - fill flash on the camera to expose the non-flash portion of the vintage camera - and tell whoever is operating the vintage camera to fire as soon as the flash fires on the modern camera.

Use ND filters or shoot in appropriately reduced ambient light. No need to synchronise anything - so long as both cameras fire their flashes whilst the shutter is open on the modern camera.

[William W]

No maths involved -

What Colin wrote.
Drats, he beat me to the answer.
It is the similar method to stopping speeding bullets and catching wine drops in mid air -
And balloons filled with water - bursting everywhere . . .

[Colin Southern]

It is the similar method to stopping speeding bullets and catching wine drops in mid air

Yeah right ... like you'd ever waste wine like that!

[William W]

[jcuknz]

Deleted because I realise I got the wrong end of the stick
Second attempt
You do not need any extra gear just a couple of humans who can work together.
You start with a dark room and the model knowing how to trigger the flash bulb as she holds the camera.
She gives you a count down and when she says 'one' you open your shutter with your camera perhaps on 'second blind' sync to fire your lighting.
Her flash bulb goes off and then your flash and you have the shot.
This is basically what happened below with the photographer, broad brim hat left of light, giving some 20<30 photographers a count down to open their shutters using Bulb while he triggered his three flash units.
My interest was showing the event rather than the subject matter.


Cumbres and Toltec Scenic Railroad 40th celebrations August 2010 ... Cumbres, Colorado/New Mexico border