Mixing flash with ambient light

[Shootar401]

Is there a trick to mixing ambient lighting either from a room our outdoors to flashbulbs? Or should I just set my shutter speed for my ambient reading and just fire the flash at the correct f-stop?

 

[markbarendt]

Depends on your flash unit.

What are you using?

Does it have an auto mode?

 

[BrianShaw]

Frashbulbs don't have an auto mode.

 

[BrianShaw]

Yes, Mr. 401... you can do that. If using fast shutter speed (> 1/60 or so) you should check to see if "flash efficiency" adjustments should be made.

 

[Matthew Wagg]

Yes and no. As Mark says above it depends on your speedlight. If you have a TTL speedlight then its pretty easy. If you go manual and have a flash that is capable of changing its power output then again yes but its a bit more work on your part.

In the latter what you want to do is meter for ambient then set your flash for a stop higher than ambient if you're doing portraits or between a 1/3rd to a 2/3rds lower if its still life. Its really a case of how much influence and what kind of look you're going for with the flash. If you have a Dslr you can use that to meter the flash output and then use it as a reference for the film, or use a flash meter (which are worth their weight in gold) or run a test roll through the camera with various settings of power for the flash at all the angles.

 

[Bob-D659]

OK, shutter speeds do make a huge difference with flash bulbs. So does film type if you are mixing light sources. Are you using blue or white bulbs and colour or b&w film.

 

[markbarendt]

Shutter speed, as long as it is within sync speed, only matters for the ambient exposure because the flash itself is really fast, typically shorter than 1/1000 at full power, much shorter at lower settings.

 

[BrianShaw]

Mark... amigo... the original post refers to flash BULBS.

 

[markbarendt]

Mark... amigo... the original post refers to flash BULBS.

So, no auto?

Doh.

 

[markbarendt]

Is there a trick to mixing ambient lighting either from a room our outdoors to flashbulbs? Or should I just set my shutter speed for my ambient reading and just fire the flash at the correct f-stop?

So after Brian straightened me out.

The trick is your second question. Aperture for flash control, time for ambient.

 

[Shootar401]

I have both clear and blue, I'll probably us the clear with B/W film. I think the guide number is 400 or so

 

[Bob-D659]

The bulb package should have chart on it. what shutter speed is that guide number for? Yes, no need to waste blue bulbs on b&w film.

Also does your shutter have an M sync position. If only X you have to use slow shutter speeds as it take approx 20 milliseconds for the bulb to reach full brightness. Also if the bulbs are labelled FP, they have a much longer burn time for the old slow transit speeds of focal plane shutters on press cameras.

 

[Shootar401]

Thanks for all the info.

I have about 300 or so FP flashbulbs mostly 31 and 2A's with some 3 & 11 mixed in.

But I'm asking specifically about the Bantam 8 & #5's I'll use it with this lens....

 

[BrianShaw]

Make sure you are using a Graflex synchronizer to trip the solenoid. That will provide the proper delay between bulb flash and shutter release. Your shutter is X synch so using the internal flash circuit will not work for bulbs.

 

[mopar_guy]

Ok, so you are going to get a mix of ambient and flash. The ambient light should be a relatively steady source. The flash bulb will be a known amount of light. You have two options to change the balance of ambient to flash. First you can use some sort of filter over the flash lamp and reflector. Many years ago the photographer may have used something like a linen handkerchief to reduce and soften the flash. The second way to reduce the flash output was to move the flash bulb farther away from the subject. There are auxiliary flash units for this purpose. You need to run a cord from the synchronizer to the "side" flash unit.

 

[benjiboy]

I suggest you meter the ambient light exposure then add one thickness of clean white cotton handkerchief fastened with a rubber band over the flash reflector will reduce the bulbs output by one stop, or two thickness's two stops.