Aperture controls the flash exposure. What about ambient?

[Fellipe de Paula]

Was watching the Zack One Light DVD and in the fist chapter he makes clear that apperture only controls the flash exposure.
I really want to know what about the ambient light amount... Doesn't it makes ambient light to pass more or less thru the lens too?
Shutter speed is ambient light. period.
ISO is both, right?
Apperture is both too, isn't it?

[bohdank]

Yes to all.

[runninmann]

Was watching the Zack One Light DVD and in the fist chapter he makes clear that apperture only controls the flash exposure.
I really want to know what about the ambient light amount... Doesn't it makes ambient light to pass more or less thru the lens too?
Shutter speed is ambient light. period.
ISO is both, right?
Apperture is both too, isn't it?Perhaps what he said or meant is not that aperture only controls flash exposure, but only aperture controls flash exposure. That is, shutter speed does not affect flash exposure.

[TMR Design]

Zack discusses exposure in its entirety on the DVD's.
Flash exposure is controlled by aperture and ambient exposure is controlled by shutter speed. The longer the shutter is open the more ambient light will be allowed to contribute to the exposure.

[doidinho]

Zack discusses exposure in its entirety on the DVD's.
Flash exposure is controlled by aperture and ambient exposure is controlled by shutter speed. The longer the shutter is open the more ambient light will be allowed to contribute to the exposure.

I think it would perhaps be more accurate to say aperture effects both the ambient and flash exposures; however, aperture is chosen to given the desired flash exposure.

Once the desired aperture is chosen, the ambient can then be adjusted by changing the shutter speed and without effecting the flash exposure.

The reason I make the distinction is that one could construe from your post that aperture only effects the flash exposure and not the ambient, which I know you didn't mean to infer.

[GenuineRolla]

The aperture also has a say in the ambient exposure as well.

If i shoot 1/200th at f/4, then there will be a good amount of ambient lighting around (assuming this was taken outdoors)

If I shoot at 1/200th at f/16-f/22 - then a lot of the light is going to be killed, if not all of it.

[Mark1]

The aperture also has a say in the ambient exposure as well.

If i shoot 1/200th at f/4, then there will be a good amount of ambient lighting around (assuming this was taken outdoors)

If I shoot at 1/200th at f/16-f/22 - then a lot of the light is going to be killed, if not all of it.


True, but your example does not match the question. When you involve stobes the "rules" change.

[rammy]

I would say that shutter speed is for the ambient light because the flash pops very quickly and the wider the aperture, higher the ISO, the more the fractional pop of the light enters through the aperture and "tingles" the sensor.

The length of the shutter speed before or after the flash then lets more of the ambient light hit the sensor for a slightly longer time and so exposing that light too.

[Marloon]

correct! Ambient is shutter speed, ISO both, ap is both, and ap is flash.

[DMOEsq]

http://strobist.blogspot.com/2007/10/lighting-102-assignment-balance.html