Digital Photography Advice
HDR Part 1
HDR Part 2
HDR Part 4 Uvas Canyon
Santa Teresa Pueblo HDR Sunset
HDR Sunset Norred Trail
Bay Area Back Pages
Bay Area Biking
SF Bay Area Rec. & Travel Home
Bay Area Parks
High Dynamic Range
Part 3: Cottonwood Lake,
Hellyer County Park
from part 1 and part 2, here
are more experiments using Photomatix to generate HDR pictures. These
are pictures taken with a compact digital camera.
1/10/10, most of the day was cloudy and overcast. I happened to be in
the Evergreen area. Near sunset, I noticed the clouds were breaking up,
and I might be able to get some nice sunset pictures. I was close to Hellyer
County Park, which has Cottonwood Lake. The lake is one of my
take sunset pictures. I wanted to take HDR pictures, but I didn't have
my SLR with me, only my Canon
Powershot A720 IS compact camera. I
didn't have time to rush home and get my SLR, so I thought I'd try
taking HDR pictures with my compact.
This will answer the question, "Can you take HDR pictures with a
compact camera?" It depends on the camera's capabilities. If it is a
very simple point-and-shoot with everything totally automatic and
fixed, then the answer is probably no. If the camera allows adjusting
the exposure, then it probably can. The key factor is how easily and quickly
the exposure can be adjusted. If
it has auto-bracketing and burst mode like most SLR's, then there is
little difference from using an SLR, and it should be easy. If it has
manual adjustments, they likely require pushing some buttons or going
through menus. For my camera, I put it into manual mode, select the
aperture, and use the cursor wheel to adjust the shutter speed. Since
this requires fiddling with the camera, a tripod or some means of
stabilizing the camera is almost essential. Fortunately, I had my tripod with me. On
my camera, in manual mode, I get a live preview of the exposure on the
LCD screen. I varied the shutter speed to make sure I got the
highlights and shadows properly exposed, taking a shot every factor of
2 in the speed. Here are some examples. The next 2 pictures below are
two of the conventional pictures used for generating the HDR picture
conventional picture was exposed for the sky. Note how most of the
foreground and shadow areas are black. This was taken at 1/1500 second
at f3.5, ISO 100.
conventional picture was exposed for the foreground, which makes the
sky grossly over-exposed and turns it all white. This was taken at 1/50
second at f3.5, ISO 100.
is an HDR picture at the same location, but a few minutes later and
from a slightly different angle. I used a fixed aperture and varied the
shutter speed in order to maintain a constant depth of focus. Whether
this is necessary or not depends on a lot of factors, but it is
simplest to use a fixed aperture. This was made from 5 pictures with shutter
speeds of 1/40 to 1/1002 second at f3.5, ISO 100.
directly into the sun is one of the hardest shots in photography. The
dynamic range is enormous. The sun hitting the lens can cause all kinds
of lens flare problems. It drives camera exposure systems crazy. Using
conventional photography, most of the time, you get silhouettes or a
burned out sky. HDR imaging is one way of dealing with these problems.
In this picture, the shutter range was 1/80 to 1/600 second at f3.5,
ISO 100. The first few shots I took were straight into the sun when it
was higher above the horizon, and the lens flare was severe. Once it
had gone down more, as in above, the flare was minor.
was made from 6 pictures with shutter speeds of 1/40 to 1/1244 second
at f3.5, ISO 100. Note how the bottom of the clouds are illuminated
with the yellow-orange sunset light, reflected in the lake. Contrast
this with the pictures taken earlier and later.
This was made from 7
pictures with shutter speeds of 1/20 to 1/1244 second at f3.5, ISO 100.
Note how bright the foreground is. To get this with conventional
photography would require a powerful flash or large reflectors.
This was made from 6
pictures with shutter speeds of 1/15 to 1/501 second at f3.5, ISO 100.
This shows even more foreground.
As the sun got lower,
the exposures got longer. This was made from 6 pictures with shutter
speeds of 1/15 to 1/501 second at f3.5, ISO 100. It began to rain
briefly, causing the rings in the water.
This was made from 5
pictures with shutter speeds of 1/15 to 1/251 second at f3.5, ISO 100.
the sun has set, the dynamic range is narrower, but still difficult to
capture by conventional photography. The light is a lot lower, so
photographing the foreground properly requires long exposures. The use
of a tripod or some means of stabilizing the camera is a must to get a
proper exposure of the foreground. This was made from 5 pictures with shutter
speeds of 1/8 to 1/202 second at f3.5, ISO 100. I could have used a
higher ISO setting to be able to use a faster shutter speed, but the
noise would have increased. Since I had a tripod, and the objects
weren't moving, a slow shutter speed wasn't a problem.
last picture was made from 6 pictures with shutter speeds of 1/8 to
1/201 second at f3.5, ISO 100. Note how the color of the light hitting
the clouds has become redder than the earlier pictures. Not long after
this, the sun went farther down, and the clouds were gray. Also, the
park closes at sunset, so I had to leave.
pictures were taken over a short span of time. The first was taken at
4:49 pm. The last was taken at 5:12 pm. This shows the importance of
timing, especially with sunset pictures. The window of opportunity for
sunset pictures can be very short, so it is important to be in the
right place at the right time. It is good to have some places in mind
to go to take pictures when it looks like the conditions will be right.
Cottonwood Lake is one of those places for me. The lighting at sunset
constantly changes, especially if there are moving clouds. For best
results, stick around and take lots of pictures over time. Don't just
take one and rush off.
One problem with HDR photography is that it has problems when objects
move from picture-to-picture. This can happen if there are people,
animals, or objects moved by the wind. Fortunately, there were few
people and birds around, the wind had died down, and the clouds were
not moving fast. Wind causes ghosts in the foreground as trees and
grasses move. Fast-moving clouds cause ghosting and multiple images in
the sky. That's when a camera with burst mode and auto-bracketing comes
in handy, like my SLR. For relatively static subjects like this, the
compact camera worked fine.
I have a licensed version of Photomatix, so the pictures don't have
watermarks any more.
Pictures by Ronald
Horii. Page created 1/21/10, updated 1/28/10