Week 4

Previously we looked at the three ways we can control light entering the camera to create the photo.  Remember the exposure triangle and how we have to balance the three exposure aspects of the triangle to obtain correct exposure.  
This weeks task was to try and incorporate lines into your photograph.  Well done to everyone for having a go.
Tonight I wanted to talk about light and where it comes from and some of the problems that can occur, but while thinking it through I decided that I needed to mention White Balance and the Histogram first.

White balance 


The light in our photographs has a colour temperature.  The diagram below shows different light sources and their associated colour temperatures.  

We normally do not notice the change in lighting as our brains adjust accordingly, but you may have noticed an occasion when an item purchased in a shop appears to be a different colour once seen in daylight.
To produce a photograph with a “true” white light the camera must know what type of light it is receiving.  This is done by setting white balance.  The camera will have a Auto white balance setting which on the whole does quite a good job, but if we set it manual we will obtain much more accurate results.
If you investigate the settings available for white balance you will find direct sun, flash,  artificial light, cloud & shade.
To understand this whole white balance thing try and set your camera white balance to Sun.  Now set up a shot indoors with some artificial lighting, preferably the type from a tungsten bulb with a filament.  Now change the white balance to artificial and take some more shots.   Hopefully you will notice  a difference.

Here’s some shots I took.

Shot 1
Artificial light and Daylight white balance.

Shot 2 
Artificial light and Tungsten White Balance

Notice the white flowers are actually white in the second shot.

Histogram
The histogram is available on many of the lower end cameras now and can be very useful in deciding if exposure is correct for a particular photo.  The histogram can be read easily, it represents the brightness levels in the scene.  The left hand side represents the very dark levels and blacks, the right hand side represents the very light levels and the levels in between are distributed between them.

Photo 1

The histogram shows a large peak on the right, this shows the blackness of the night sky, the small peak at the right is due to the small amount of bright levels in the skeleton and  white tree.

 

Photo 2

The histogram shows some peaks near the right, these are due to the dark foliage in the back ground. There is then a good distribution of levels and a tail off towards the brighter end on the right.

Photo 3

This photo taken on a sunny day part in sun and part in shadow gives a histogram shows a large peak of darkness on the left, a distribution in the middle but then a small peak on the right

 

Photo 4

This is a real example of what happens when settings are not correct.  I took this at a wedding a few years ago and had left a setting incorrect. ( Maybe I should have left it on auto)  Some of the faces and the detail on the white shirts are completely over exposed and nothing can be done on the computer later to fix this problem.  If you look at the histogram there is a large peak on the right which equates to these overexposed areas.

Photo 5 

The histogram for this photo shows a nice peak in the centre which conventionally  denotes a well exposed photo.

Direct Midday Sunlight

This light is harsh and does not create desirable shadows.  Photographers can potentially struggle with shadows and lit subjects to create exposure headaches. Try to get your subjects into shade if possible.   Flash can be used to fill in shadows or white reflective material can be used to fill-in the darker areas of your subject.

Afternoon / Morning Light.

Coming from a more favourable angle the light creates interesting shadows.

 

Sunrise / sunset - Golden hour. 

The hour before sunset or after sunrise.

With clouds lit from above and below this light creates skies in the background, but also a lovely soft warm light for your subjects.   But to capture the warmth of the scene you will need to ensure that you set your white balance yourself.  

Dawn / Dusk - Blue hour

 The hour after sunset or before sunrise.

Natural light levels are low so slow shutter speeds become necessary.  A tripod or resting the camera on a stable surface is essential.  If you allow the camera to set the exposure, it will probably overexpose the whole scene,  and we'll lose the saturation of the colours so we need to take control and tell the camera what we want.

Overcast

One tip is to leave the sky out of your shots if at all possible as it will just look white and uninteresting.  But at least you will not have to struggle with shadows.  Use this diffuse light to your advantage and pick subjects for their colour rather than texture / shape that would be better displayed with some shadow.

Indoor lighting

This is relatively low level, so slow shutter speeds are the order of the day.  Keep the camera steady.

You do have full control over this light so use it to your advantage.  Don't forget to set your white balance.

I've added a Printer Friendly Button 
John and Joyce noticed that if you try to print the blog, you end up with one long list of each weeks post.  Potentially this means that by Week 12 you could be using a lot of paper.
So after some poking around down the back of the internet sofa I found a button that is added after each weeks post.  Take a look. . . . .

Take a external links and have a look at Cheap Camera - Pro Photographer.

 

This Weeks Task

This weeks Funtography  (Task) -    find the white balance setting on your camera, set it on sunshine and take some shots  indoors with tungsten lighting.     This is so that you to notice the difference that  white balance makes.

Wherever you are, be aware of where the light is coming from. Can you move your position?, the position of the subject?, can you move the light source or wait until the sun/weather changes?

Indoors (get your white balance correct again)   try and set up a shot and control the light you use.  The light may be from a window or an artificial source, and / or use a reflective surface to compensate for shadows.

 

See you next week.

Mark