EXERCISE: A Scenes Dynamic Range

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

Take five differently lit scenes, and within each, find and measure the brightest and darkest areas.  You di exactly this for the previous exercise in order to measure the camera’s range, but here the emphasise is on variety of picture situation.

Make sure that at least one scene has a very high dynamic range (a tip: if a light source, or its reflection, is included in the view, the range will inevitably be very high), and also that at least one scene has a low range – appears ‘flat’, in other words.  Other than this, there is no limits to the scenes you choose, because an important part of this exercise is exploration and discovery.  Note the results in your learning log.

I walk along the banks of a local river most mornings, and during my recent outings I began to formulate a plan for using one of the rivers bridges as the subject for this exercise.  The reason behind my thinking this possible is that I would be able to cover all of the requirements of the exercise, and also have a theme running through the shoot.

This exercise took two attempts to achieve as my proposed shooting day rose cloudy, so I was able to take the photo for my low dynamic range image; then the afternoon was sunny, so I was able to complete the shoot with my high dynamic range and other images.

I set my white balance accordingly and dialled in the widest aperture my sensor would allow.  As I would be using my shutter speed to read the dynamic range during this exercise, I set my camera’s metering to spot.

The hardest of all the photos to get right is my first image, which was taken in the general direction of the sun.

Shutter Speed 1/640; Aperture F3.8; Focal Length 32mm; ISO 100; Metering Spot; WB Sunny

Shutter Speed 1/640; Aperture F3.8; Focal Length 32mm; ISO 100; Metering Spot; WB Sunny

 

Shot into the sun

Shot into the sun – with meter readings

After trying a few shots, I concentrated my metering on the archway closest to the camera as doing this gave me the best overall exposure.  The sky is still a little blown, especially in the direction of the sun, but there is still some detail and colour above the bridge.

The brightest part of the photo is under the bridge and to the left, with a shutter speed reading of 1/2500th, the darkest part is contained within the furthest reaches of the arches, where the shutter speed read 1/60th.  This gave me sixteen stops of dynamic range – so there is quiet a dramatic difference in the lightest and darkest areas of the image.

Next I changed position and shot with the sun behind me, with its rays shining onto the façade of the bridge.

Shutter Speed 1/1000; Aperture F3.8; Focal Length 35mm; ISO 100; Metering Spot; WB Sunny

Shutter Speed 1/1000; Aperture F3.8; Focal Length 35mm; ISO 100; Metering Spot; WB Sunny

 

Shot away from the sun - showing metering

Shot away from the sun – with meter readings

Again, trying a few shots, I concentrated my metering on closest archway to my camera as this again gave me the best overall exposure for the shot.  Although the initial meter reading is high at 1/1000th, this image is well exposed with no clipping present in the sky, which is the biggest difference between this and the previous photograph; in fact here the sky is a brilliant shade of blue.  My lowest reading of 1/100th was found under the first archway, and the highest 1/2000th was found by concentrating on the houses between the two pillars, this gave me a total of 13-stops difference in the dynamic range.

Next we have a high-key image.

Shutter Speed 1/100; Aperture F4.5; Focal Length 32mm; ISO 100; Metering Spot; WB Sunny

Shutter Speed 1/100; Aperture F4.5; Focal Length 32mm; ISO 100; Metering Spot; WB Sunny

 

High-Key image - with meter readings

High-Key image – with meter readings

Using the archway around mid point of the image, my initial shutter speed for this shot was 1/100th, which was expected due to this being a central part of the structure with only the light reflected from the water penetrating the cement of the pillars.

The brightest point of this shot 1/125th, and can be found where the sun is hitting the water and reflecting on the archway.  The darkest point, found in the crevices of the arches reads 1/60th, giving a total of 3-stops of light difference.  These readings are not what I expected from an image that is classed as high-key, an image that is mostly light in nature, but there is little difference between the three readings, meaning that the shot is quiet evenly exposed.

My penultimate shot has a low dynamic range

Shutter Speed 1/10; Aperture F4.5; Focal Length 58mm; ISO 100; Metering Spot; WB Sunny

Shutter Speed 1/10; Aperture F4.5; Focal Length 58mm; ISO 100; Metering Spot; WB Sunny

 

Flat image - with meter readings

Flat image – with meter readings

This image was taken underneath the bridge, so I was in the shade.  I also had the added bonus of there being no sun to cast light into the archway.  Although the graffiti is quiet dynamic, the surrounding cement is very flat, which is confirmed by the even metering across the image as in three of the four corners I managed a reading of 1/8th in comparison to the 1/10th received when I took the shot.  The colours, aside from the graffiti, in the photo probably helped to flatten the light, but as concrete is unforgiving, absorbing most of the natural light and not repelling it, probably helps to get the results of this shot.

My final image is a general riverside scene

Shutter Speed 1/1250; Aperture F4.5; Focal Length 28mm; ISO 100; Metering Spot; WB Sunny

Shutter Speed 1/1250; Aperture F4.5; Focal Length 28mm; ISO 100; Metering Spot; WB Sunny

 

General river scene - with meter readings

General river scene – with meter readings

As I had previously experienced difficulties when shooting in the direction of the light, I decided to take my final shot with the sun behind me.  Instead of concentrating on smaller areas of the subject, here I decided to open up my view and take in a general vista of the river and the bridge.

With the detail of the image running through the centre of the frame, to expose correctly I used the opposite river bank as my initial point of focus, this gave me a meter reading of 1/1250th.  This reading was expected due to my opening up the view and having such a great source of light behind me from the sun.  The darkest part of this image are the trees to the left of the frame giving a shutter speed of 1/800th, the lightest parts are the buildings above the bridge, which gave a reading of 1/1600th.  In total this was a difference of 3-stops, which is lower than I thought it would be, but then the light has made this shot quiet even.

Conclusion:

This turned out to be far more interesting than the previous dynamic range exercise and the results have given me further insight into how my camera performs and how it produces different images under different lighting situations.

I did not find this task too difficult to undertake, as I have always been mindful of my exposure, especially as I have never relied on post-processing to make changes to my photos, and by looking into the metering of different areas of an image really makes me think more about my overall exposure.

I am also learning that light, and the different ways to use it in photos really does make a difference to our shots; very little light, such as on a dull or overcast day, can make things quiet dull and unappealing, whereas more light can make things come alive and highlight lots of detail in our shots.  Building on this further, too much light washes detail away much the same as not having enough light will do, so getting the balance right makes all the difference to our work.

As our camera sensor reacts according to the amount of light it has to expose our images, by shooting towards a light source, it needs to be less sensitive than when shooting away from a light source, in other words when shooting towards the light we need faster shutter speeds to let in less light, but when we need a little more light, we need to slow things down to let the light in.

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