There are five variables at play when shooting with flash.
They are:
1. f/stop
2. shutter speed
3. flash power
4. flash to subject distance
5. iso
You must understand this concept for this to work:
f/stop determines the exposure of the subject
shutter speed determines the exposure of the background (and how much
the ambient light impacts your subject)
say that again:
f/stop determines the exposure of the subject
shutter speed determines the exposure of the background (and how much
the ambient light impacts your subject)
and one more time:
f/stop determines the exposure of the subject
shutter speed determines the exposure of the background (and how much
the ambient light impacts your subject)
With a quick glance of the histogram you will be able to tell if you
need to adjust your f/stop or shutter speed or both.
Here's how it works.
Pick an f/stop and shutter speed combination at your usual iso.
It doesn't matter what that combo is but if you need to be concerned
with depth of field (large group for example), take that into
consideration.
Let's say f/5.6 at 1/60th at iso 400. I picked these numbers from a
cloud.
Set your flash to manual, put it on your camera, aim it to bounce at
the ceiling for a nice soft effect (soon you'll want it to be off
camera and we can deal with that in a future email), dial it up to
full power (you'll stop shooting full power and conserve battery juice
once you get the hang of this, I promise).
Find a subject. A loved one sitting in a chair, a bowl of fruit, a cat
on the couch, anything will do. Take a shot.
After you take it look at your histogram
How does it look?
Is it blinking wildly showing blown highlights ON YOUR SUBJECT
(disregard the background for now) ?
If the answer is yes you need to change something.
You can:
dial down your flash power (I rarely shoot inside using more than 1/2
power)
you can close down your f/stop
you can move further from your subject
you can choose a lower iso
Do not do a thing to your shutter speed (because it only impacts the
ambient light, not the flash light).
Change one of those things and take another shot.
Look at your histogram.
Did your blinkies stop?
If so, great.
If not, keep adjusting one thing until you get your subject properly
lit.
These are the adjustments I make in this order:
change f/stop
change flash power
change flash to subject distance
change iso
If your SUBJECT is too dark, open up your f/stop, move your flash
closer to your subject, dial up your flash power or choose a higher iso.
Once your subject is properly lit you need to spend some time thinking
about the background.
In your test shots is your background too dark or would you simply
like to see more detail in the background?
If the answer is yes you need to slow down your shutter speed to let
more ambient light in.
If your background is too bright or you'd like to see less background
clutter you need to speed up your shutter speed to allow less ambient
light in.
This is a good time to say you need to know what your camera's max
sync speed is. You can't go over it or you'll get that black band
(which is actually your shutter closing down) in your image.
This sounds like a lot of steps and it is but JUST DO IT. Do it over
and over. Adjust your f/stop. Adjust your shutter speed. Adjust your
flash power. Adjust your flash to subject distance. Take shots and
LOOK at what each of these changes does.
Do tests until it becomes second nature. It will happen in no time.
The first few times I tried this I thought I'd never get it and then
BOOM the lightbulb went off and it was seared into my brain.
Before long you will be able to set your flash and your camera
settings, take a couple quick test shots and have everything set with
no more than one or two test shots.
I'm not kidding. It really does become that fast.
And if you're into off-camera flash (and shouldn't we all be?) it
works just exactly the same. You just have to have a way to fire your
flash from your camera.
I am open to questions about this so bring them on.
Lea
babies. they're what i do.
www.leamurphy.com
