2WK
Rangefinder User
Ok so I have a mamiya 7ii and I put an old olympus flash (from an OM-2).
The flash has full manual settings. If I am shooting outside in daylight, and say I set the aperture to 8, how do I know what shutter speed to set? I obviously can't use the auto exposure setting on the mamiya, since the camera is unaware of the flash and will get blown out.
Thanks!
The flash has full manual settings. If I am shooting outside in daylight, and say I set the aperture to 8, how do I know what shutter speed to set? I obviously can't use the auto exposure setting on the mamiya, since the camera is unaware of the flash and will get blown out.
Thanks!
JoeV
Thin Air, Bright Sun
You'd have to know the guide number of the flash, plus have a light meter to get a reading of the scene. Using the reference chart that's usually attached to the flash, set it to your film's ISO speed, read the distance to the subject using the camera lens' distance scale, then reference the required f-stop needed on the flash's chart. This would be an aperture required to fully illuminate the scene at the focused distance; but what you want to do is to under-expose the flash exposure, mixing it with an under-exposed ambient exposure.
So, set your camera's aperture and shutter speed to 1 stop under-expose the ambient scene, at an f-stop that 1-stop under-exposes the flash reading. This will give you a 50-50 mix of ambient and flash, at the focused distance.
This is all assuming your camera has a leaf shutter and syncs flash at all speeds. With a curtain shutter, the calculation gets a bit more complicated.
Example:
Flash recommends f/11, ambient meter reads f/11 at 1/250 second. Set the camera's exposure to f/16 at 1/250. This will under-expose both the flash and the ambient by 1 stop; when both exposures are mixed together, you should get nearly a normal exposure with a mix of flash and ambient lighting.
~Joe
EDIT: I'm not familiar with the 7ii's metering system - does it give you an indication of shutter speed at each aperture setting, before taking the shot? If so, you can use it as your default ambient light meter.
So, set your camera's aperture and shutter speed to 1 stop under-expose the ambient scene, at an f-stop that 1-stop under-exposes the flash reading. This will give you a 50-50 mix of ambient and flash, at the focused distance.
This is all assuming your camera has a leaf shutter and syncs flash at all speeds. With a curtain shutter, the calculation gets a bit more complicated.
Example:
Flash recommends f/11, ambient meter reads f/11 at 1/250 second. Set the camera's exposure to f/16 at 1/250. This will under-expose both the flash and the ambient by 1 stop; when both exposures are mixed together, you should get nearly a normal exposure with a mix of flash and ambient lighting.
~Joe
EDIT: I'm not familiar with the 7ii's metering system - does it give you an indication of shutter speed at each aperture setting, before taking the shot? If so, you can use it as your default ambient light meter.
Landshark
Well-known
I think JoeV meant to to say change EITHER the aperture or shutter speed.
But when I use fill, I use the ambient reading as a base exposure and stop down one stop
JoeV has you stop down two stops.
Try 'em both it's only a frame or two and the results will be different enough so you can choose what's right for you.
For something that's quick & dirty, you can use an automatic flash like a Vivitar 283/285 on Auto. You set the camera for proper exposure and leave the flash on auto. That works most of the time without using the GN chart.
I don't remember if the Oly flash has anything besides a TTL flash option.
But when I use fill, I use the ambient reading as a base exposure and stop down one stop
JoeV has you stop down two stops.
Try 'em both it's only a frame or two and the results will be different enough so you can choose what's right for you.
For something that's quick & dirty, you can use an automatic flash like a Vivitar 283/285 on Auto. You set the camera for proper exposure and leave the flash on auto. That works most of the time without using the GN chart.
I don't remember if the Oly flash has anything besides a TTL flash option.
Vics
Veteran
Go top Strrobist.com and take the free Strobist 101 course there (top of the page. You'll learn all about manual (the only way to go) flash and lots more about off-camera flash. Great site.
http://www.strobist.blogspot.com/
And of course you'll need a flash meter (Sekonic L-308s, e.g.)
2WK
Rangefinder User
Thanks buddies. I shot a few rolls on skid row LA a few days ago. Excited to process and see.