The photography world is buzzing
nowadays with the latest technique in creating perfect
exposures every time - the High Dynamic Range (or
HDR) photo. Using a series of images ranging from
underexposed to overexposed, a perfect image can be
blended together using Adobe Photoshop CS2 or CS3,
assuming you've got the right equipment and follow
the procedure accordingly. It may be a bit daunting
at first, but it can quickly become second nature.
The first thing you'll need is, of course, a camera.
But not just any camera will suffice. In this case
a Digital SLR camera, such as a Canon Digital Rebel
XTI or 5D, is recommended to take advantage of multiple
shutter speeds. If you have a point-and-shoot camera
that will allow you to manually adjust both shutter
speeds and aperture, that will work as well. If
you've never worked in M mode, or changed around
those settings much, you'll learn how here.
Next you'll need a tripod. This unfortunately isn't
optional because the images that Photoshop merges
all have to be identical and can not have shifted
at all. No matter how steady your hands are, they
will produce shaking and none of them will line
Another piece of equipment you may want to consider
using is a shutter-release cable to prevent camera
shake when the shutter button is pressed. It seems
like a lot, but it's worth it.
Onto the technique! A good practice subject is
a sunset because they're readily available and that
will also show you the true power of an HDR photo.
Find a scenic spot so that you can see the sun on
its way down and set your camera into M mode. You
could technically use Tv mode, which allows you
to control just the shutter speed, but we'll stick
with M mode just to make sure the aperture also
remains constant. Most cameras have a small light
meter built into them and will tell you if your
exposure is potentially over or underexposed. Using
this meter, move your shutter speed down so that
the meter is at the -2 and take your first shot.
Now that you've got one, just how many photos do
you actually need to create a good HDR photo? Technically
Photoshop only needs three to work, but ideally
you'll want between 10 and 15. Why so many? This
gives Photoshop a larger range of values to work
with when blending between lights and darks, and
thus, creating a smoother transition and more aesthetically
appealing photo. So with your first photo captured,
increase the shutter speed a bit and take a series
of 10-15 photos gradually increasing the shutter
speed for each one until you're at the +2. The photography
part is done! Now pack up and head back to your
computer to see your new HDR image.
Using Adobe Bridge (bundled with Adobe Photoshop),
select all of the photos you took for the image
and go up to Tools -> Photoshop -> Merge to HDR.
Photoshop will begin working and at this point,
you wait. In fact, no matter how fast of a computer
you have, this process will take a while. Go make
a sandwich. Actually you'll also have time to eat
the sandwich. You know what? You'll even have time
to clean up the dishes after you eat your sandwich.
How bout a drink?
Well if you're computer is relatively new, it should
be close to done by now. You'll know when it's done
because it will present you with a dialog box verifying
which images you want to use, all of them checked
by default. In most cases you'll want to hit OK
Now you're left with an image that doesn't look
so great. It's ok though, all information is stored
in there in much deeper levels than you're used
to working with as 32bits per channel. In order
to clean it up and create the photo you were wanting,
you'll first have to convert it to 16bits per channel.
This can be done by going up to Image -> Mode ->
16bits/channel. This will open up another dialog
box with four options in a drop-down menu. 99% of
the time you won't have to worry about the first
three. Instead, select the fourth one and then click
the arrows at the bottom-left to expand the window.
After doing this you'll notice that your image looks
even worse now behind the Curves window that was
just expanded. At this point it's just a basic Curves
window and if you have experience with curves, you
probably know what to do here. If you don't, or
you need a bit more explanation, the bottom-left
area controls the shadows and the top-right area
controls the highlights. You'll notice a histogram
behind the curve (at this point a diagonal line).
Drag the bottom-left point to line up with the very
edge of that histogram and you'll notice the shadows
in the photo become more pronounced. Do the same
with the top-right point and you'll notice the same
happening to the highlights. Be careful not to overexpose
Now it's almost ready to go. This final step though
can be a bit tricky and certainly takes practice.
The great thing about Curves is that you can add
a point anywhere on the line and drag it to bring
out more highlights or shadows or midtones. It takes
a bit of playing around with and since every photo
is different, there's no magic formula. The thing
to remember though is that you want your curve,
ironically, to be as straight as possible. You still
want to create bends though because that will create
contrast, but just don't get too excited with them
as that can create unwanted effects.
Give it a little practice. Now that you know the
technique, you're able to do it all you want! Also
don't be afraid to try it on things other than sunsets,
some interesting effects can be found by using this
technique on night shots, water, skies, etc.
About the Author:
Visit Mike Cavaroc at http://www.cavaroc.com