Could someone explain this...

I was just reading this in a book I just bought "Photographing People. Portraits, Fashion, Glamour"

"Where the lighting is electronic flash, only the aperture is given, as illumination is of course independent of shutter speed."

I'm not sure what is meant by this.

Also, any other good lighting book suggestions appreciated.

Thanks,
Jeff
--
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http://www.photosig.com/userphotos.php?id=17960
http://www.pbase.com/jhsinger
D60, 28-135IS, 50mm f1.4, 75-300IS

jsinger986 said:

I was just reading this in a book I just bought "Photographing
People. Portraits, Fashion, Glamour"

"Where the lighting is electronic flash, only the aperture is
given, as illumination is of course independent of shutter speed."

I'm not sure what is meant by this.

Click to expand...

The duration of a flash is measured in thousandths of a second, so as long as the shutter is fully open when the flash fires the shutter speed makes little or no difference. The exception to this is where the ambient light is sufficiently strong to affect the overall exposure, but in most studio situations there is nowhere near enough available light to do this. Obviously you need to make sure that the shutter speed on the camera is set in the range between the maximum synch speed and a speed at which the ambient light does make an impact. If you want to make sure, use the maximum synch speed.

Neil.
--
http://www.dg28.com

So essentiually you can set the exposure manually and not even worry about the shutter speed up until the synch speed? Does this mean you always shoot in manual mode when in a studio with any shutter speed you want?

Thanks for your reply!

I was actually attempting to recreate your "The Interview Portrait" today.

Just when I think I understand something I read something new and get confused all over again!!!!

Jeff

Neil Turner said:

jsinger986 said:

I was just reading this in a book I just bought "Photographing
People. Portraits, Fashion, Glamour"

"Where the lighting is electronic flash, only the aperture is
given, as illumination is of course independent of shutter speed."

I'm not sure what is meant by this.

Click to expand...

The duration of a flash is measured in thousandths of a second, so
as long as the shutter is fully open when the flash fires the
shutter speed makes little or no difference. The exception to this
is where the ambient light is sufficiently strong to affect the
overall exposure, but in most studio situations there is nowhere
near enough available light to do this. Obviously you need to make
sure that the shutter speed on the camera is set in the range
between the maximum synch speed and a speed at which the ambient
light does make an impact. If you want to make sure, use the
maximum synch speed.

Neil.
--
http://www.dg28.com

Click to expand...

--
--------------------------------
http://www.photosig.com/userphotos.php?id=17960
http://www.pbase.com/jhsinger
D60, 28-135IS, 50mm f1.4, 75-300IS

Imagine if you were shooting in a completely dark room, no ambiant light at all. When you fire your flashes, all the light that the camera will ever see happens in an instant (1/3000th of a second, or something in that range). As long as the shutter is open when the flash fires, the only thing that will affect how much light the camera sees, and therefor what exposure you get, is the apature - the size of the opening between the light source and the film (or imaging element). In that situation, it doesn't matter if the shutter is open for 1/200th/sec, or 10 minutes... all the light for the exposure happens in just a fraction of that time.

It's not quite this simple though, since you might have enough ambiant light to affect the exposure. If, for example, you're in a room lit by a few big north facing windows, then there might be a difference in exposure between 1/60th sec and 1/200th sec at the same apature. Most flash meters will tell you how much light is from the flash, and how much is ambiant for a given exposure time.

jsinger986 said:

Thanks for your reply!

I was actually attempting to recreate your "The Interview Portrait"
today.

Just when I think I understand something I read something new and
get confused all over again!!!!

Jeff

Neil Turner said:

jsinger986 said:

I was just reading this in a book I just bought "Photographing
People. Portraits, Fashion, Glamour"

"Where the lighting is electronic flash, only the aperture is
given, as illumination is of course independent of shutter speed."

I'm not sure what is meant by this.

Click to expand...

The duration of a flash is measured in thousandths of a second, so
as long as the shutter is fully open when the flash fires the
shutter speed makes little or no difference. The exception to this
is where the ambient light is sufficiently strong to affect the
overall exposure, but in most studio situations there is nowhere
near enough available light to do this. Obviously you need to make
sure that the shutter speed on the camera is set in the range
between the maximum synch speed and a speed at which the ambient
light does make an impact. If you want to make sure, use the
maximum synch speed.

Neil.
--
http://www.dg28.com

Click to expand...

--
--------------------------------
http://www.photosig.com/userphotos.php?id=17960
http://www.pbase.com/jhsinger
D60, 28-135IS, 50mm f1.4, 75-300IS

Click to expand...

Jeff

Generally in a studio type setting the shutter speed doesnt matter except that it has to be slower than your cameras max sync speed.

Depending on the ambient light and your shutter speed you may pick up some ambient light also but flash will be your main light source and the duration of the flash which is much faster than you shutter speed will determine the exposure.

--
Michael Salzlechner
StarZen Digital Imaging
http://www.starzen.com/imaging

jsinger986 said:

So essentiually you can set the exposure manually and not even
worry about the shutter speed up until the synch speed? Does this
mean you always shoot in manual mode when in a studio with any
shutter speed you want?

Thanks for your reply!

Click to expand...

Yes, settings should be manual in a studio strobe situation. You will not be using TTL flashes. I take it you do not have a flash meter, based on your questions. You will probably need to pick one up for convenience and eventually for measuring ratios. Not necessary with digital but will still save you time.

--
Jim DeLuco
DeLuco Photography
http://www.delucophoto.com

One reason why its good to understand this is that you can expose the background to your liking with the shutter setting when shooting with flash on location.

I sometimes "blow out" the back ground with a slow shutter when on location as the examples below show



http://www.photoshift.com/portfolioDetailF19.html
http://www.photoshift.com

Mike Salzlechner said:

Jeff

Generally in a studio type setting the shutter speed doesnt matter
except that it has to be slower than your cameras max sync speed.

Depending on the ambient light and your shutter speed you may pick
up some ambient light also but flash will be your main light source
and the duration of the flash which is much faster than you shutter
speed will determine the exposure.

--
Michael Salzlechner
StarZen Digital Imaging
http://www.starzen.com/imaging

Click to expand...