Controling ambient light with sutterspeed

[joel28]

Hi Everyone,

I read in a few books/articles where photographers write that they prefer to to use the Shutter speed tool to control how the camera records ambient light. How would it be different when using aperture or ISO (when DOF is not an issue) ?

Thanks for your help!

 

[fjrabon]

Aperture and ISO will equally control both ambient light and light from flash. Shutter speed only controls ambient light because the flash flashes for a shorter duration than than the shutter is open.

So, for instance if the flash is flashing for 1/250 a sec, and the shutter speed is 1/125, speeding the shutter speed up to 1/200 won't effect the light coming from the flash. But it will effect the ambient light.

 

[rexbobcat]

From my understanding aperture has a more profound effect on ambient light while shutter speed mostly effects the "amount" of flash that shows up in the photo...

 

[fjrabon]

From my understanding aperture has a more profound effect on ambient light while shutter speed mostly effects the "amount" of flash that shows up in the photo...

well, aperture effects flash and ambient equally though. shutter speed has little/no effect on flash, but it can make the flash seem comparatively brighter or darker, by lowering or raising the amount of ambient.

 

[joel28]

Aperture and ISO will equally control both ambient light and light from flash. Shutter speed only controls ambient light because the flash flashes for a shorter duration than than the shutter is open.

Thanks for your response!

What about continues lighting?

 

[fjrabon]

Aperture and ISO will equally control both ambient light and light from flash. Shutter speed only controls ambient light because the flash flashes for a shorter duration than than the shutter is open.

Thanks for your response!

What about continues lighting?

Continuous lighting acts exactly like ambient lighting.

 

[2WheelPhoto]

If you are using a combo of available light and flash, shutter speed will mostly control ambient and fstop changes will make the big difference in your strobe/flash level. ISO should be at native default if you are have good available light and strobe.

 

[KmH]

Hi Everyone,

I read in a few books/articles where photographers write that they prefer to to use the Shutter speed tool to control how the camera records ambient light. How would it be different when using aperture or ISO (when DOF is not an issue) ?

Thanks for your help!

It depends how much ambient light there is.

If all the light in a scene is ambient light, shutter speed, lens aperture, and ISO are used normally.

When strobed light is used as the main light source, the usually short duration of the flash of light takes over the shutter speed job of stopping motion.
With sufficiently powerful strobed light, the lens aperture/ISO used controls the strobed light exposure and the shutter speed controls the ambient light exposure.
As mentioned, continuous lighting is effectively ambient lighting, so motion stopping and exposure control go back to normal exposure triad function.

When shutter speed is used to control ambient light exposure when using strobed light, there are limits imposed by how the camera shutter works. A key camera specification is it's flash (strobed light) x-sync speed.
Most DSLRs today have a 1/200 or 1/250 x-sync speed.
The x-sync speed is the fastest shutter speed that allows both shutter curtains to be fully open. At faster shutter speeds the 2 shutter curtains form a slit. The faster the shutter speed the narrower the slit.

Strobed light photos can still be made, but because of the slit the strobe light has to fire multiple times during an exposure, and that presents a technical problem.

A hot shoe flash fired at full power takes at least a couple of seconds to recharge so it can fire again. When your shutter speed is set to 1/500 and the flash needs to fire multiple times in that 1/500th of a second there is way insufficient time to recharge the flash units main capacitor. So the multiple flashes have to be made using very much less than full power.

This is the world of Canon HSS (high speed sync) and Nikon Auto FP sync (FP = focal plane). Most entry-level cameras and flash units cannot do HSS/Auto FP. Of those that can, HSS/Auto FP put great demands on flash units and batteries.

Shutter/Flash Synchronization - YouTube

 

[Village Idiot]

If you are using a combo of available light and flash, shutter speed will mostly control ambient and fstop changes will make the big difference in your strobe/flash level. ISO should be at native default if you are have good available light and strobe.

ISO can be a good way getting more effecient flash usage. If you crank your ISO up 2-3 stops without negatively affecting the image quality, you can turn your flash down 2-3 stops for faster recycle time, faster flash duration on certain flashes, and more pops if you're working off batteries.

 

[2WheelPhoto]

If you are using a combo of available light and flash, shutter speed will mostly control ambient and fstop changes will make the big difference in your strobe/flash level. ISO should be at native default if you are have good available light and strobe.

ISO can be a good way getting more effecient flash usage. If you crank your ISO up 2-3 stops without negatively affecting the image quality, you can turn your flash down 2-3 stops for faster recycle time, faster flash duration on certain flashes, and more pops if you're working off batteries.

Agree 100%. In good available light and with my strobes I shoot at native per my comment.