lighting ratio in studio

magicpic

In a studio, if the main light is say f 8 and you stopped down two stops for the fill or shadow would it be f 18....hope to hear just learning about studio..janis

wxwax

2 stops would be f16.

f stop scale.

ziggy53

wxwax wrote:

2 stops would be f16.

f stop scale.

Wasn't life somehow easier when SLR lenses (and interchangeable rangefinder lenses and interchangeable TLR lenses, etc.) had the full stops marked on them. With these newer "fly by wire" lenses, you just don't get the same experience. :cry

Then again, 1/3 stops control and not having to (remember to) change each lens aperture with a lens change, maybe it's not all that bad?

ziggy53 (Showing his age more with each passing day.)

BenA2

Tangential question

magicpic wrote:

In a studio, if the main light is say f 8 and you stopped down two stops for the fill or shadow would it be f 18....hope to hear just learning about studio..janis

For my own education, when one states that a light is "at" an f number, does that mean that the scene it lights meters at that f number at the system's max sync speed?

Thanks

ziggy53

BenA2 wrote:

For my own education, when one states that a light is "at" an f number, does that mean that the scene it lights meters at that f number at the system's max sync speed?

Thanks

Almost! Using a flash (incident) meter to measure a flash output indicates an f setting that is the effective aperture, and the shutter should be set to the sync speed "or slower", assuming that that one flash is the only source of light/illumination.

If there is ambient light, or if there are more than one contributing flash, then it is simply a measure of that particular light, and the appropriate exposure of the camera is "partially" determined by that singular measure. All sources need to be considered, as well as their ratios to each other, to determine the taking exposure.

ziggy53

BenA2

ziggy53 wrote:

Almost! Using a flash (incident) meter to measure a flash output indicates an f setting that is the effective aperture, and the shutter should be set to the sync speed "or slower", assuming that that one flash is the only source of light/illumination.

If there is ambient light, or if there are more than one contributing flash, then it is simply a measure of that particular light, and the appropriate exposure of the camera is "partially" determined by that singular measure. All sources need to be considered, as well as their ratios to each other, to determine the taking exposure.

ziggy53

Thanks Ziggy. I was having a hard time with there not being a shutter speed specified as well. But, now that you say this, and I think about it, it doesn't matter that the shutter speed can be longer than the sync speed, since the flash duration is shorter. So, by that rationalle, once you set your aperture to the metered flash value, the more you decrease your shutter speed, the more you shift your balance toward ambient.

I've gone too many years without knowing the answer to that question .

pathfinder

BenA2 wrote:

Thanks Ziggy. I was having a hard time with there not being a shutter speed specified as well. But, now that you say this, and I think about it, it doesn't matter that the shutter speed can be longer than the sync speed, since the flash duration is shorter. So, by that rationalle, once you set your aperture to the metered flash value, the more you decrease your shutter speed, the more you shift your balance toward ambient.

I've gone too many years without knowing the answer to that question .

Absolutely!!

Ambient light is controlled by shutter speed, and flash lighting is controlled by aperture, since the flash illumination is so brief that it is not affected by shutter speed ( as long as it is in synch with the shutter opening)