Category Archives: 1 – (Natural light) The intensity of light

Exercise-Measuring Exposure-2

In this exercise I have taken 5x images of the same subject to learn how the deliberate choice to slightly over or under-expose may sometimes benefit the picture.

The first as recommended by the camera’s light meter, the second half-stop darker, third one-stop darker, fourth half-stop lighter and fifth one-stop lighter.

This exercise is typically known as ‘Bracketing’ and this idea originates from the days of film photography.  When a subject has both challenging contrasts of light and shade photographers would often take 3 or 5 shots at different exposures to try to get an image that was closest to capturing detail in both dark areas of an image and in the bright areas.  Starting from the light meters recommended exposure to above and below in half or one-stop increments. Manufactures such as Nikon added this as a feature in their later SLRs and for the newer DSLRs keeping the name ‘Bracketing’.  This useful feature will automatically alter the exposure for the chosen number of shots from half-stop to one-stop increments with the choice of number of shots from 3, 5, 7, etc.  With the advent of digital photography and the development of software to manipulate the digital images ‘Bracketing’ has become a new science and art-form in the photography world with the development of High Dynamic Range (HDR) software that can combine all the bracketed images into one picture that can now make possible the inclusion of all the detail in both bright areas and dark areas of a scene that previously was not.  This however, often makes for a very hard / gritty contrasty type of image limiting their use.

Images shot as recommended by the light meter.
Average-1-resized Average-2-resized Average-3-resized Dad-1-mid-tone (1 of 1) Dad-2-mid-tone (1 of 1)

1a                             2a                                      3a                                      4a                       5a

Half a stop darker
Half_stop_darker-1 Half_stop_darker-2-resized Half_stop_darker_3-resized Dad-1-minus-half-stop (1 of 1) Dad-2-minus-half-stop (1 of 1)

1b                            2b                                     3b                                    4b                        5b

One stop darker
One_stop_darker-1-resized  One_stop_darker-2-resized One_stop_darker_3-resized Dad-1-minus-one-stop (1 of 1) Dad-2-minus-one-stop (1 of 1)

1c                            2c                                        3c                                       4c                       5c

Half a stop lighter
Half_stop_lighter-1-resized Half_stop_lighter-2-resized Half_stop_lighter-3-resized Dad-1-plus-half-stop (1 of 1) Dad-2-plus-half-stop (1 of 1)

1d                           2d                                      3d                                      4d                       5d

One stop lighter
One_stop_lighter-1-resized One_stop_lighter-2-resized Oner_stop_lighter-3-resized Dad-1-plus-one-stop (1 of 1) Dad-2-plus-one-stop (1 of 1)

1e                           2e                                      3e                                      4e                        5e

My selection of best images are as follows:

1c This provides the most contrast in the detail of the stone figure with shadows offering a good sense of texture and form.  This image is one-stop over the recommended exposure as indicated through my camera’s light meter.

2a In this subject I think that the recommended exposure works best.

3c Again the darker, one-stop above recommended exposure works best for Holly’s fur coat.

4d I feel that this image looks best, half-stop brighter than the suggested exposure giving an up beat / high-key tone.

5a I believe that this is the best choice and is the exposure recommended by my camera’s light meter.  It has some rim-light that helps him stand out from the background and there is sufficient contrast for a modelling affect.

Reference material:

Basics Photography 07, Exposure.  by David Prakel. Published by AVA Publishing

 

 

Exercise-Measuring exposure-part-1

In this exercise I have taken photographs using my light meter to help me produce images that are either deliberately lighter (high-key) or darker (low-key) to suit the intention of the subject.

My first image was deliberately intended to be dark to create an atmosphere of mystery and imagination. Is he entering this room or is spying on someone?
Beyond the door-resized
I used spot metering to take a reflective reading off the chrome door handle in order to get an overall dark effect with a bright slit shining through as the door is opened and good exposure for my hand. Narrow depth of field to add depth, camera set to manual, ISO 400, WB – Auto. f/2.0, 1/60sec hand held, ambient light only. This exposure was 4x stops above the suggested averaged exposure of 1/25sec to under-expose the image. Post production was kept minimal with very little cropping needed, just a small adjustment for levelling and the image sharpened and no other adjustments made.

Dolls_eyes-resized

For this image, I overexposed by one stop, ignoring my camera’s suggested setting of 1/100 at f/5.6 and using a setting of 1/50 at f/5.6 instead for a brighter image whilst remaining inside the boundary of the Histogram to avoid clipping the high lights.

In this image the room was dark; so I over exposed by one full f-stop in order to compensate and make the image brighter.
My camera recommended 1/90, f/2.4 I chose 1/90, f/3.3 instead.
_Plus_one_full_F_stop (1 of 1)

In this last low-key image, taken in the garden on an overcast afternoon, I took this image two stops below the camera’s recommended exposure of 1/2000, f/4 choosing 1/8000, f/4 to create a darker and more sinister feel for this still-life.
ISO 400, white balance sunlight.
Demons (1 of 1)

Exercise – Higher and lower sensitivity

In this exercise, I took my DSLR camera in to a local market on an overcast day and took a range of photographs adjusting the ISO from 800 to 100 in order to practice taking advantage of the adjustability to sensitivity to light that modern digital cameras have and see what trade offs were made for the greater sensitivity.

The following images were taken altering the ISO whilst keeping the internal reflective light meter centred for the cameras recommended exposure settings:

ISO 100, 1/60, f/19
ISO-100-a (1 of 1)
ISO 800, 1/350, f/22
ISO-800-a (1 of 1)

ISO 100, 1/60, f/11
ISO-100-b (1 of 1)
ISO 800, 1/180, f/22
ISO-800-b (1 of 1)

ISO 100, 1/90, f/9.5
ISO-100-c (1 of 1)
ISO 800, 1/500, f/16
ISO-800-c (1 of 1)

ISO 100, 1/125, f/5.6
ISO-100-g (1 of 1)
ISO 800, 1/60, f/22
ISO-800-g (1 of 1)

ISO 100, 1/60, f/11
ISO-100-h (1 of 1)
ISO 800, 1/90, f/22
ISO-800-h (1 of 1)

ISO 100, 1/30, f/16
ISO-100-i (1 of 1)
ISO 800, 1/125, f/22
ISO-800-i (1 of 1)

ISO 100, 1/20, f/8
ISO-100-k (1 of 1)
ISO 800, 1/500, f/4.8
ISO-800-k (1 of 1)
Note from the exposure information included with each image that when set to a higher ISO setting in most cases I obtained both a faster shutter speed and a higher aperture for a greater depth-of-field.

The digital revolution in photography now gives photographers the ability to adjust the sensitivity of light exposure without having to swap film to a faster or slower ASA speed.

The advantage of this new feature is that photographers can now quickly and easily adjust the sensitivity of their cameras to get that shot when in less light than was ever possible in the past.

However, just as in the days of film a price still has to be paid for this greater light sensitivity. In the past it was a graininess in the image when a photo taken using a fast film was enlarged and printed. This was produced by the tiny silver-oxide crystals in the light sensitive film emulsion which were much larger in the faster / more light sensitive films than they were in the slower / less sensitive films. Now we have a similar effect that we call noise, a grainy speckle of different coloured tiny dots that can appear in the darker parts of an image, produced by the light sensitive pixels from the electronic light sensor which again becomes more noticeable when the image is enlarged and printed.