Mountain-Light
HOW TO USE THE HISTOGRAM
One of the most useful tools in a digital camera is the Histogram. To be able to use it properly we first need to know what it is.
There are two types of Histograms, the one at the back of DSLR cameras and the one that is displayed in Photoshop at the editing stage. The one we are interested in here is the one at the back of the digital camera - that one can help us at the time the photograph is being taken to get a good exposure.
What does the Histogram do?
It measures light and dark tones. The Histogram at the back of the camera measures the light of the scene at the time of taking the photograph.
A good photograph will have a wide range of tones. What happens if the range of tones is too great, for example on a very bright sunny day? In such a situation it may be impossible to find an exposure which records some detail in the shadows without blowing out the highlights or vice versa.
This measurement of light and dark is represented by a graph - on the left hand side is 0 (zero) representing black, absence of any light. On the right hand side is the number 255, this will print paper white without any detail. The middle point represents 18 % grey.
The more intensive the shade or colour is in the scene, the taller the peaks in the graph will be.
What can we do when faced with an extreme brightness range in the scene?
We can do a number of things:
a) - We can use neutral grey graduated filters to bring the sky exposure down by a number of stops.
b) - Take two or more pictures with different exposures and then merge them,
c) - Can you look for a different angle that will bring down the contrast in the range of the scene?
d)- Compromise and lose detail in the area you consider less important.
Often a compromised is the obvious and most practical choic
What can we do to bring in some detail in the important area of the image?
The biggest advantage digital has over film is the fact that we can check our shot once we have taken it and after some adjustments we can take it again.
So, in our example we can do just that - increase or decrease the amount of light entering the camera so that the lines on the Histogram graph do not go beyond the right and left hand margins and re-take the shot.
We must remember that by Dialling in some underexposure or overexposure to bring some more detail into the scene, we can take the edge off the image. So, we must think and try to visualize what we want the final image to look like - the camera cannot do the thinking for us.
To summarise
The Histogram is a great tool if used properly. To learn how to use it start by reviewing the picture you take in camera and if the contrast range is greater than the camera can record - for example extreme brightness, consider the four points above.
After each picture, study the results. Take notes and then when you view them while image-editing in Photoshop study the results.
Our eyes have a much larger Dynamic range than a digital camera - for proper exposure we need to learn how the camera sees things.
One of the most useful tools in a digital camera is the Histogram. To be able to use it properly we first need to know what it is.
There are two types of Histograms, the one at the back of DSLR cameras and the one that is displayed in Photoshop at the editing stage. The one we are interested in here is the one at the back of the digital camera - that one can help us at the time the photograph is being taken to get a good exposure.
What does the Histogram do?
It measures light and dark tones. The Histogram at the back of the camera measures the light of the scene at the time of taking the photograph.
A good photograph will have a wide range of tones. What happens if the range of tones is too great, for example on a very bright sunny day? In such a situation it may be impossible to find an exposure which records some detail in the shadows without blowing out the highlights or vice versa.
This measurement of light and dark is represented by a graph - on the left hand side is 0 (zero) representing black, absence of any light. On the right hand side is the number 255, this will print paper white without any detail. The middle point represents 18 % grey.
The more intensive the shade or colour is in the scene, the taller the peaks in the graph will be.
What can we do when faced with an extreme brightness range in the scene?
We can do a number of things:
a) - We can use neutral grey graduated filters to bring the sky exposure down by a number of stops.
b) - Take two or more pictures with different exposures and then merge them,
c) - Can you look for a different angle that will bring down the contrast in the range of the scene?
d)- Compromise and lose detail in the area you consider less important.
Often a compromised is the obvious and most practical choic
What can we do to bring in some detail in the important area of the image?
The biggest advantage digital has over film is the fact that we can check our shot once we have taken it and after some adjustments we can take it again.
So, in our example we can do just that - increase or decrease the amount of light entering the camera so that the lines on the Histogram graph do not go beyond the right and left hand margins and re-take the shot.
We must remember that by Dialling in some underexposure or overexposure to bring some more detail into the scene, we can take the edge off the image. So, we must think and try to visualize what we want the final image to look like - the camera cannot do the thinking for us.
To summarise
The Histogram is a great tool if used properly. To learn how to use it start by reviewing the picture you take in camera and if the contrast range is greater than the camera can record - for example extreme brightness, consider the four points above.
After each picture, study the results. Take notes and then when you view them while image-editing in Photoshop study the results.
Our eyes have a much larger Dynamic range than a digital camera - for proper exposure we need to learn how the camera sees things.
Landscape and Wildlife Photography