DYNAMIC RANGE - EXERCISE

Scene dynamic range.

With some idea what dynamic range your camera can cope with measure the dynamic
range of some scenes ,

• Take five different lit scenes 
• Measure the lightest and darkest points
• Show examples of both high and low contrast.

IMAGE ONE 

natural light

overcast sky

white balance - preset to sky

neutral density filter

f25

I shot this image for this project as I had a variation

of light and dark to account for.

Aesthetically it is a poor image but there is great variation

between the light flat sky at 1/25 sec to 1/50 sec meter reading

and the foreground 1/5 to 1/3 sec exposure setting.

I bracketed a series on images shooting down at shutter speed

from 1/25 sec

From this series I choose 1/5 sec to process as it this speed

as 1/3 sec meant that the lightest point of the sky was burnt

out and I had clipped highlights in the sky.

at 1/10 sec which is a mid point between the lightest and

darkest point meant that the foreground detail and the

pillars were too dark and I was concerned I could not

bring back the detail in Photoshop

f25
1/5 sec

PROCESSED IMAGE

• level adjustment. light added to no dark
• contrast adjustment
• burn brush foreground and under pier to add light
• dodge brush sky to bring out cloud detail
• red filter mono processing to highlight tones and contrast 
• of light and dark

IMAGE 2

f4.5
iso 200
1/50sec

I choose to use this London street scene for this exercise as
I could visually see that there was a great variation in light
and shade in the scene. I used the spot meter in the camera
to measure the lit variations. The foreground was very dark
with shutter speed starting at 1/10 sec to 1/50 sec in the
mid tones of the scene. The background read at 1/125 sec
and the bright sky read at 1/250 sec. The scene was also
lit by two tungsten lights which also change the dynamic range
of exposures in this scene.


Processed Image.

• processed as a high dynamic image
• black added to foreground to add drama
• light added to mid tone in center of image to bring out detail of bricks
• and to draw the viewers eye into the scene.
• black added to sky and back ground
• light burnt in foreground to show highlights around the window
• in front right of image
• contrast levels increased to make the image more dramatic
• bright tungsten masked and dark added to reduce brightness

IMAGE 3 

F8
1/100sec
iso 200
overcast sky
white balance pre set

The above image was taken at 1/100 which was the reading
for the reflected light off the water. The darker foreground is
very visually under exposed as the TTL reading was 1/15 sec

I bracketed the image down from 1/100 sec. At 1/15 sec the
image is very exposed on the water and side of the bridge.


Processed Image

• processed as a high dynamic image
• dodge brush to add some addtional white under bridge
• contrast added

IMAGE 4

F22
overcast grey sky
wb daylight

This image was taken on an overcast rainy day and I saw
this reflected image of St pauls in the railing of the new modern
shopping center opposite the cathedral. I measured the
lighting variance across the scene and there was variations
from light to dark. The railing which was reflecting the sky red
at 1/180 sec but the same sky read at 1/160sec reflecting from
glass panel. This clearly shows how reflected surfaces light reading
can vary. The darker area of the scene gave a light reading of
1/80 sec.This was the light reading of the darker building
reflecting in the chrome rail.

processed image

• processed as a neutral density image
• level adjustment
• contrast added ( which has made this image more dynamic than planned)
• dodge brush to add some additional white to the building area
• colour tone balanced and saturation level increased

IMAGE 5

F5
1/20 SEC
wb daylight

This image was taken in a tunnel under Southwark bridge.
the light was limited but there was a shard of light
shinning back onto the stone surface which created the
contrast of lighting. I used the TTL on aperture priority to
read the light avail. The light varied from 1/100 sec for the
bright back ground to the 1/10 sec in the very dark foreground
which was furthest from the light source.

processed image

IMAGE 6

F6.3
1/60 SEC
WB daylight

This very low contrast image was taken at a memorial near
Hyde park. I had been struggling to find low contrast image
as the weather had been so stormy the light was
very contrasty. This memorial was in complete shade and
so I managed to take this image under very flat lighting
conditions. The reading variations were minimal as the only
area of contrast was the white paper attached the cross
detail.

processed image

• processed as a low contrast
• level adjustment, white added
• contrast added , to add some depth to this flat image
• colour balance changed to add red to warm image
• saturation increased
• filter for sharpness

CONCLUSION AND LESSONS LEARNT

This exercise has been a challenge in the winter lighting conditions

as I have often been shooting in contrasting lighting conditions.

I have used different surface conditions to read light from which

shows that the light reflected back of of varying surfaces will need

to be considered when shooting a scene. I have also used this

exercise to bracket exposure and can clearly see that the contrast

is affected by the exposure at which the scene is captured. I

have concluded that an average exposure ( between the highest and

lowest point) is ideal to use. I have been able to add/ change the

contrast detail in photoshop. As in linear capture you do not lose the

detail of the image and light and dark can be added in photoshop.

The low contrast images I took had no depth as there was little

variation in the light on the scene. Again I have managed to add

depth to the images by changing contrast in photoshop.

I still think that I need to continue to work on my exposure

setting. I believe I always seem to shoot one stop below the

optimum exposure level. When I look at the histogram on the 

camera I am happy with my curve capture but in PS the image

seems to require some light ( added ).

I am now going to make sure I shoot images, and bracket

one over and one under of each image and log these and

can monitor the results when I process in photoshop.
I also have conclude that I prefer

high contrast images and I have processed most images

with high contrast variation between light and dark.

I will continue to try to shoot more low contrast images.