Tag Archives: Camera control

The Exposure Triangle – An aid to thinking about exposure

The Exposure Triangle

• The Exposure Triangle •
Click the image to download an A4 *.pdf version to print.

Going manual with your DSLR.

For many people exploring manual settings is a challenge. There is a lot to learn. Without guidance it is difficult to work it out for yourself. Here is my approach to the subject.

Why the exposure triangle

The “Exposure Triangle” is a memory aid to help us balance light for a good exposure.

One thing you should remember. The exposure triangle is NOT a calculator. The aim is to help you get used to using the settings. The ‘Triangle’ loses its importance once you understand the settings. Instead you will see your visualisation of the shot as more important.

Beyond auto-settings

“Auto settings” in modern cameras are average types of shot. They are pre-set in the camera programming. Sports mode freezes the action; landscape mode gives deep focus in the shot; portrait mode promotes close focus and so on. The pre-sets make credible pictures but take creative decisions away from you. Controlling exposure gives you artistic control over our photos.

It’s all about control

Photographs capture light reflected from objects in the scene. Too much light – the object is over-bright, or worse, blown out (completely white). Too little light and the light does not excite the sensor enough. Thnthe object is dark, sombre, or worse – black. At the extremes we have blown out or black. In between are a whole range of capture intensities.

The trick is to balance the incoming light so the sensor can make the picture as we wish it to come out. the idea is to control the light in-camera to create optimal light conditions for the sensor.

Three essential elements

There are three critical elements that control the incoming light…

  • ISO: controls the sensitivity of the sensor and how we capture the light brightness. A sensitive sensor allows a shot in lower light conditions (example: ISO100). High sensitivity to light is referred to as High ISO (example: very high ISO = 3000). The penalty is the picture becomes noisy (Definition: Digital Noise) as the ISO gets higher. Noise affects the quality of the picture. The lower you keep the ISO, the better quality the final image will be.
  • Aperture: controls the amount of light allowed through the lens. It also controls the depth of field. As the aperture increase the amount of light entering the lens also increases. However, as the aperture gets bigger the lens loses the ability to focus at infinity. As the focus shortens part of the picture is not so clearly defined. Taking a photo at F4 means you might be able to focus on a face beautifully and with sufficient light. But you may not be able to discern any detail behind the head. The depth of field has been shortened by the wide aperture.
  • Shutter value or Time value: How long the sensor is exposed to light affects the amount of light you collect. Leave the shutter open too long and the shot is too bright, blowing out parts of the picture. Close the shutter too quickly – the result is underexposed. Long exposures tend to exaggerate movement introducing blur. Fast shutter speeds tend to freeze an object in place.
What is exposure?

There is no right or wrong for achieving the outcome we desire. But there is only ONE point at which the exposure (all three elements combined) is right for your picture. That is the one to make your photo come out the way you want. You must find the correct exposure balance for your visualisation of the picture using all three elements.

Exposure is the right balance of ISO, Aperture and Shutter speed which provides for your intended depth of field, movement blur, brightness and representation of the scene. It is a unique response to the sensor settings you think will make your shot come out right.

The Exposure Triangle is a concept to help you adjust the balance to get the exposure right. The key to using the exposure triangle is that the three elements of exposure: ISO, aperture and shutter speed, must always balance.

It teaches us to understand how the three exposure elements play off one-another. Shorten one arrow the others will need to accommodate by adjusting their length. You can increase one or both of the other elements to accommodate the change.

If you increase one element you will need to decrease one or both of the other elements to accommodate the change.

Full Manual Control

Our exposure settings aim to balance the three elements in the camera. This needs to be done on the ‘Manual’ setting or ‘M’ setting to get the desired result. To gain full creative control we must do two things…

  • First we must have a clear idea of what we are going to achieve for each shot. Do we want the water blurred in our stream or not? Do we want the final picture to look bright and breezy or dark and sombre? Do we want movement blur or sharp, frozen action… and so on. So look at the scene and determine what you want.
  • Secondly, on the basis of what we want we must adjust the camera settings to achieve the desired result.

How do we adjust the settings to get the optimal exposure? Simple. The camera light-meter indicates when exposure is optimal.

The DSLR light sensor is the key

Inside every DSLR is a digital sensor. It detects light intensity. If the light is correctly optimised it will be indicated on the exposure meter.

With the camera set to “M” look through the eye-viewer. At the bottom of the screen you will see a scale. There should be a needle above the scale. This is the indicator of the current exposure. The centre of the scale is the correct exposure level for most shots.

If the needle is off to the right the sensor is getting too much light. If it is off to the left there is insufficient light. The trick is to balance ISO, aperture and shutter speed so the needle is centred.

Your camera manual will show you how to change each of the three settings. There are normally three controls somewhere on the DSLR body to change each of them. Again, your camera manual should have a diagram of the readings in your viewer screen when you look through it. Check out that diagram. You will see the location of the settings on the screen that will change when you alter the controls.

A trick to get you started…

Put the camera on full automatic (the ‘green square’ setting). Take a shot like the one you want. Now look at the settings for that picture on your camera screen. Your camera manual will show you which setting you can look at on the screen. This gives you a guide to what your manual settings should be for this shot.

Now switch to ‘M’ or manual to vary the results. If you want movement blur then slow down the shutter speed (longer exposure, more light let in) and/or decrease the aperture (reduce incoming light) to keep the needle in place. One click of longer shutter speed needs one ‘f-stop’ less of aperture to keep the exposure optimal. But now you get the movement blur!

The aim here is to balance a change in one element by changing one or both of the other elements. In the process you try to keep the needle over the centre of the scale in your viewer. The centred needle tells you you have an optimal exposure that your sensor can use.

Experience…

If you practice regularly with your camera on ‘M’ you will get control of your shots. Try to relate the settings to the type of results you get. Relate shutter speed to the resulting blur/sharpness. Similarly, relate depth of field to aperture size. Relate ISO to balancing light sensitivity to achieve the correct sensitivity for your intended exposure. Gaining experience with these attributes will help you remember settings to use in particular situations.

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Damon Guy (Netkonnexion)

Damon is managing editor of Photokonnexion.com with professional experience in photography, writing, image libraries, and computing. He is also an experienced, webmaster and a trained teacher. Damon runs regular training for digital photographers who are just starting out.
See also: Editors ‘Bio’
By Damon Guy :: Profile on Google+

Get your settings right with all file types

File-formats and settings

The power of the file format you use…

Most photographers don’t think about settings and file formats when starting. First off, most people just want to take pictures. Down the road you need to think about what you are doing more carefully. You will need to get into RAW processing to overcome the shortcomings (but also, see my comment after this article)

File formats

When you think about settings and file formats it appears very technical. It’s not easy to work out what you need to know. Here are the basics. There are two in-camera file types for photographers…

  • RAW = a file type for capturing all the data from your camera, but which needs developing (post processing) after the file is downloaded. There are many manufacturer-specific versions of the RAW format.
  • *.jpg = a specific file type created in-camera from a RAW file. It is processed by the camera. The *.jpg format was originally designed only for transmitting and displaying files. It is extremely limited for post processing and easily degraded.

Both file types are useful for certain things. The RAW format is ultimately the most useful for photographers because it is so flexible. It allows you to develop the image you want from the picture you have taken. The *.jpg file on the other hand is processed for you, in a limited auto-processing system over which you have little control. It is confusing for beginners because *.jpg files create reasonably good images. But it is difficult to make them do what you intend. Beginners eventually find they cannot create the excellent images that RAW users produce. Nevertheless, starters use *.jpg because they don’t understand RAW and processing – they are stuck without help.

The processing is already done for *.jpg files by the time they are downloaded. Most beginners think they have something special when they get a great image straight out of the camera. Actually they are getting something processed according to someone else’s ideas. So it is not entirely their creation.

How do you break out of this situation?

The easiest way is to do a course or join a club or both. Then you can gain the experience and techniques you need to learn while having fun with others who share your interests. There are lots of courses and clubs around. More specifically you will have three goals. You need to learn how to…

  • Control your camera to get the picture you want.
  • Do post processing to produce great images.
  • See great scenes and compose them to create great images.
Along the way…

At some point every aspiring photographer is told, “why not try moving to RAW, that format gives you greater control over your processing”. This is true and a worthwhile pursuit.

What most beginners also hear along the way is something like this… “It is easier to shoot in RAW because you don’t need to worry about your settings so much”. “You can sort it out in post processing”.

This whole “sort it out later” attitude is a recipe for disaster. Here is my reasoning…
Most beginners:

  • Have an underdeveloped sense of colour.
  • Are not sensitive to light intensity or brightness variations.
  • Have an underdeveloped sense of the quality of light.

And crucially…

  • Cannot properly remember the colours shades, tones and brightness levels at a scene until they can start the post processing hours or days later.

The result is that during processing colours, brightnesses, tones and shades get over/under processed owing to no reference point. The resultant image is often a long way from reality. Incidentally, as your eye/mind system develops the “photographers eye” you begin to remember these details much more.

I urge you to cultivate the habit of fine control of your camera. Every shot, or at least every set of similar shots, should be set up individually. Be obsessive about it. Then, when you get your work into the computer, your post processing has a realistic starting point. It is easier, and more realistic, to process a picture that starts out very close to your intended image.

There is another reason to be obsessive and accurate about controlling settings from the start. Bad habits are really, really difficult to break. If you get into the habit of sloppy settings from the start you will almost certainly be a lazy photographer. I can assure you that will condemn you to many hours in front of the computer doing menial development tasks. It is much easier to get it right in-camera from the start. Then you can slightly tweak it later. Breaking a sloppy habit to get fine control of your camera later is a long, hard road.

Professional photographers are obsessive about getting the settings right. They know that the difference between an amateur and a professional is getting EXACTLY the image they want. And, they know they will not get that exact image by being sloppy. Precise, accurate and pre-set control is the name of the game if you want to create sharp, and realistic images.

So, forget about ‘rescuing images later’. Do your photography correctly from the start and do it using RAW files.

Addendum:
It is important to consider the tools you work with. If your camera does not offer the opportunity to save RAW files you have to work with what you have got. Nothing wrong with that. It is worth reading my comment after this article.

By Damon Guy (author and Photokonnexion editor)

Damon Guy - Netkonnexion

Damon Guy (Netkonnexion)

Damon is a writer-photog and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photogs.
See also: Editors ‘Bio’.
By Damon Guy see his profile on Google+.

Take an easy shot that looks like an impressive jump

Perception tells you one thing – the story of the shot another.

Extraordinary shots are the photographers goal. They’re fun and high impact. You can have a lot of fun fooling your viewer with a simple shot that is easy to take.

Here is a very quick video that lets you into the secret of taking really cool jumping shots. It’s all about point of view. Bryan Peterson, shows you how to take great jump shots and includes all the information you need to know to take the shot including the camera settings. The result is excellent…

Uploaded by AdoramaTV on Sep 16, 2011
AdoramaTV Presents “You Keep Shooting” with Bryan Peterson.

We might not all have a mountain range nearby to take photos like Bryan. However, I am sure you can apply the same technique in all sorts of places. How about in front of the elevated roadway? Or in front of a tall building? The shot looks dangerous but its all about perception. Give it a go in a location near you!

Simple techniques for photographing yourself

Most people want to have a go at a ‘selfie’.

You are a good model for trying out shots and poses. You can have lots of fun doing innovative shots of yourself. Here’s some simple techniques for self portraiture which are fun and useful.

In this video Mark Wallace shows easy ways to set up and take self portraits.

Uploaded by snapfactory on Aug 31, 2010