Tag Archives: landscape

Photographic Exposure – a simple guide

This is a post intended for my BA students but others may find it useful too.

PHOTOGRAPHIC EXPOSURE

This is controlled by 3 different though inter-related methods:

1. ISO

2. Shutter speed

3. Aperture

Finger

ISO

This is the speed or sensitivity of the camera’s sensor & is selected by the photographer. Formally it was the sensitivity of the film that you chose to load into the camera.

At the time of writing (Sep 2012) most Nikon DSLR’s use 200 ISO as their base position whereas Canon’s begin at 100 ISO (though higher spec models have a greater range).

The lower the ISO value that is selected the less the sensitivity to light that the sensor will have and the less the electronic noise/interference that will result.

As a general rule you choose a low ISO when you have a lot of light to work with and you increase the ISO to higher values as lighting conditions become darker.

The progression of ISO values you can expect to find on a DSLR are:

100   200   400   800   1600   3200   6400 +

Each time the ISO value doubles or halves this is referred to as making an adjustment that is equivalent to 1 f-stop (more on this later).

On film the common ISO progressions are:

50   100   200   400   800   1600   3200   6400 +

Offerings at San Andrés

SHUTTER SPEED

This is the time for which the shutter is open and the sensor or  film is exposed to light.

Shutter speeds are referred to as being either slow (when the sutter is open for a longer time) and fast (when the shutter is open for a short time).

You select the speed to suit what you are wanting to achieve as well as for the conditions under which you are working.

As a general rule:

Slow speeds may result in camera shake so think about using a tripod.

Fast speeds for action photography where a clear, concise image is needed.

The progression is:

< 15sec  8 sec  4 sec  2 sec  1sec  1/2   1/4   1/8   1/15   1/30   1/60   1/125   1/250  1/500   1/1000   1/2000 >

There will also be a ‘B’ (bulb) setting. This allows you to open the shutter and it will remain open until you release it.

Some cameras &/or lenses have a ‘T’ (time) setting where you press once to open and again to close the shutter.

Both ‘B’ and ‘T’ as well as speeds slower than 1/8 sec should be used in conjunction with a cable release.

Jazz for Sax

APERTURE

This is the third (and sometimes most confusing) method for controlling exposure.

This refers to the diameter of the aperture formed by the iris diaphragm, which is a series mechanical blades built into the camera lens.

The diameter of this aperture is expressed as an f-number (f-no).

There is a set progression of f-no’s & each time you change this number you increase or decrease the amount of exposure by 1 f-stop. Thus the photographic convention of expressing exposure in f-stops. This is the inverse square law in action.

The size of the lens aperture influences both overall exposure AND the amount of subject that is in ‘acceptably’ sharp  focus – referred to as ‘Depth of Field’.

As photographers we need to consider how much depth of field we require in order to be able to achieve a given result. This in turn will influence the f-no we will want to select.

When the lens is fully open to it’s widest aperture there will be very little depth of field, when stopped down to a narrow (or small) aperture you will achieve greater depth of field.

Yet more confusion comes about because a wide aperture has a low numerical value (f1.4 or 2.8) whereas a small aperture has a high numeric value (f22).

Older, non auto-fucus lenses, will have their range of f-no’s inscribed on the barrel and sometimes also the intermediate positions which may be half of third f-stops. Thus you will hear people talk in terms of fractions of a stop when considering exposure.

The standard f-no progression is:

< f1.4   f2   f2.8   f4   f5.6   f8   f11   f16   f22   f32   f45   f64   f90   >

Beware though when using a DSLR. These cameras express the intervening fractional values as f-stops & this causes added confusion. On your cameras you will see f-no’s such as f9, f14, etc. But you will not see these marked on a lens barrel or a lightmeter.

In fact modern light/flahmeters will read a full f-stop followed by fractional units in tenths. So it just got more confusing!

An example of a lightmeter reading: 1/125 sec   f5.6 9

This translates as a shutter speed of 1/125th second with an aperture that is f5.6 & 9/10.

Your camera doesn’t work in tenths (yet!) so you have to be prepared to compromise & rounding up or down to the nearest full f-stop which, in this case, is f8 or the third of an f-stop interval if that is closest.

In actual fact a 1/10th of an f-stop is not going to make a huge difference to your exposure & if necessary can be adjusted in post.

Nighttime on the M11 motorway

Use these notes as a general guide, read around the subject for yourself & experiment so that this becomes familiar.

Further reading:

Diprose, G & Robbins, J (2012) Photography: The New Basics, Thames & Hudson

A first class read, thorough, easy to follow

Adams, A (1981) The Camera, New York Graphics Society

Old school and very technical, the best there is on the subject

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Scenes of an Unexpected Nature

From 2 Aug to 2 Sep 2012 Shadows & Light Workshops presents an exhibition of images made by photographers who have participated in our programmes.

© Delphine Lytlleton

There are examples of both digital and analogue photography made with cameras varying from SLR’s through to large format. Some images where generated during Shadows and Light Workshops whilst others have come about by the direct application of skills and techniques learnt with us.

© Rosie Berwick

© Marjorie Devine-King

All of the colour printing has been undertaken by Metro Imaging Ltd.

Located at the The Phoenix Cinema Gallery, 52 High Road, London, N2 9PJ the show is open daily. The Phoenix is one of the oldest UK cinemas in continuous use, having first opened in 1910.

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iPhone in the Wilderness

Above Ladybower, Peak District

At Shadows and Light we encourage you to remain open to the unexpected and embrace it whenever you have the opportunity. Last month Matt posted a piece about using the iPhone with apps such as Hipstamatic and Instagram as a practical tool for visualisation of future shots – particularly useful for landscape work.

Over the Easter vacation I made a trip to the Peak District however the weather had turned cold with an icy wind. I walked a lot, the snow had drifted over 1 ft deep, so the iPhone was by far the best tool to use in this instance.

Sun Breaks Through, Peak District

My process is actually quite simple and is more or less unchanged to the way I go about all of my shots;

1. Look for the image first.

2. Choose the ‘lens’ and ‘film’ as offered by the app.

3. Carefully compose the shot on the screen.

4. Shoot!

Arbor Low, stone circle, ver 1, Peak District

Admittedly this is not the Phase One or Large Format but then on a day with uncertain weather and at new locations the iPhone actually allows me to generate markedly different images and just now I find it more satisfying than my Canon G9. What’s more, it fits in my pocket and weighs practically nothing – which is more than I can say for those other cameras!

Arbor Low, stone circle, ver 2, Peak District

You may think to yourself, ‘Well, they look fine on screen but they’ll never print…’ nevertheless  I’ve found that if I export the iPhone files as TIFFs then process them through Lightroom or Capture One I’m able to print full frame onto A3 paper and I still have to try them on A2 paper.

Instagram has an added advantage in that it allows you to shoot using the phone’s built-in camera then import the files into the app afterwards.

Wooden Signpost near Ladybower, Peak District

So a decidedly cold and threatening weekend has rewarded me with a bunch of unusual pictures and, at the very least, 8 – 10 new locations, some of which will come up in future Shadows and Light workshops. Keep an eye on the web site, the blog or join the mailing list to see what tours will happening in the coming months.

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Large Format Landscape

Bamburgh Castle at dawn

Details: Wista 45DX, 90mm, 4 secs, f22 2/3, Fuji Velvia 50, 0.6ND Grad

Yesterday evening I made a presentation about large format photography to the City of London & Cripplegate  Photographic Society and received a very welcome. I covered all aspects of large format that I’ve used throughout my career on both 5×4 & 10×8, from portraits to still life and on into landscape.

I now run Large Format workshops both for complete beginners through to experienced practitioners. There will be a two day introductory to large format landscape on 2-4 Nov 2012 in South Wales and refresher days on 16 March 2012, 27 April & 25 May either in London or Essex. I supply the cameras for these workshops so if you’ve been considering LF and want to experience it before buying a camera then perhaps a Shadows & Light workshop is just for you?

Another recent speaker at the same society was Red Saunders, a photographer from whom I learnt a great deal of LF skill and technique.

Apart from shooting landscape in this form I’ve also done a great deal of still life with art directors such as Pearce Marchbank.

Stone, Paper, Scissors

Details: Sinar Norma 5×4, 150mm, 1/125 sec, f22, Fuji 100D
Art Director: Pearce Marchbank, Client: Marxism Today

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