The histogram is a graphical representation of the tonal range (exposure) of an image. If you shoot with a digital camera you will be able to check the histogram of every image as soon as you have clicked the shutter. This is one of the most helpful tools you can use in the field.

The far left side of the histogram represents black, with a value of 0, and the far right represents white, with a value of 255.

If your histogram is skewed towards the left, your image is underexposed where as if the histogram is skewed to the right it is overexposed.  In digital photography an underexposed image is the worst case scenario as white areas that have been ‘burned-out’ will not retain any details and can not be corrected with post processing software.  An ideal exposure is where the histogram is spread between the two extremes, as can be seen above. In such an image you will have a full tonal range from pure black to pure white.

Rules are sometimes meant to be broken and depending on your desired outcome you might end up with histograms that look nothing like the one above.

A silhouette will for example show a hisotgram that is very skewed to the left due to the lack of pure white or very bright colours in the image.

In the example on the left you can see that the histogram spikes on the left which is a result of all the pure black in the image.  The little bubble in the middle of the histogram is the oranges which is the brightest colours in the image.

The histogram is the only way you can truly see the exposure of an image you just took out in the field.  Even though the small screens on cameras have been getting much better during the last few year it is virtually impossible to judge the exposure of an image by looking at it.  Use your histogram!

Now with most image processing software you can ‘fix’ your histogram to make your image ‘pop’.  Here is a very basic example of the results you can get by tweaking your histogram.

(Note:  I normally do a lot of my processing in RAW but for this example I have used a straight-from-RAW JPEG without any changes except for those shown below.)

This above two images of a male lion is noticeably different with the one on the right definitely having more punch that the other.  When you look at each images’ histogram you will see initially how the image on the left lacked pure black and pure white as shown by the histogram not touching the very left and right of the histogram panel.

By simply taking the two sliders and moving them left and right respectively you can make your image ‘pop’ by redefining black and white in your image.  The slider in the middle defines you mid-tones but will focus more on this at a later stage.

Now I know a lot of people do not believe in editing their images as they want it to be natural.  All good, but the above is not considered editing your images. You are not cloning in extra animals.  You are not changing the lion’s eye from yellow to orange.  You are purely completing the entire photographic process which started when you clicked the shutter.  Back in film-days we did it in the darkroom.  Now we now do it in Photoshop.

An easy to apply fix and the results speak for themselves.

Before – Image as shot.

After – Image with histogram fixed as shown above.

Use the histogram in the field, fix it on the screen and you are one step closer to creating better and more striking wildlife & nature images.  It makes a huge difference to your final image and you are not cheating!  Your images are still natural – just better!

As always I look forward to hearing from you.

Until next time.

Gerry

There has been a lot of talk as to whether you should under or overexpose when shooting with a digital camera.  The answer is simple.  You should expose correctly.

Ok, let’s look at it a little closer.  Your goal should always be to expose your image as correctly as possible.  That is ultimately your goal and the result of proper metering.  However, if you need to make a choice whether to under or overexpose remember this – always expose  right.  Not right as in correct but right as in the opposite of left.

When you look at the histogram on your camera this will make a little more sense.  For a more detailed look at the histogram check this post but the bottom line is this.  Black is on the left, white is on the right and your mid tones are grouped in the middle.  If you were to go with what many take-pictures-like-a-pro websites tell you, the histogram on the right is what you should always be after.  It starts pretty much with a perfect black, all the mid tones are grouped together in the middle and it ends with pure white.

This is all fine and well but not every scene you face will result in a perfect histogram like this.  Actually, very few do.  If yuo had to choose whetehr to uderexpose or over expose what would you do?

This is where the title comes in.  Always expose to the right.  In other words, if you are unsure always overexpose slightly so that your histogram leans to the right of the screen.  You will have much better results if you shoot slightly lighter when you post process your images.  The reason for this is that noise is most prevalent in dark areas or shadows.  If you underexpose your shots and correct it afterwards in Lightroom or Photoshop you are more likely to get noise in the dark areas of your images. Make sense?

You will get better results as darkening an image will not result in as much noise as lightening an image.

Here is an example.

The above image has been slightly underexposed.  This can be seen by the histogram leaning slightly over to the left.  I.e. the images has more dark then light areas.  You stand the chance of increased noise in the dark areas if you were to lighten this image.

This image has been slightly overexposed which can be seen from the histogram leaning to the right.  By processing this image, rather than the first version, you will end up with a better resulting image and less noise.

This is the result you get from darkening the light version of the image.  Compare the three versions and pay particular attention to the dark tire and area below the leopard’s tail and you will see that the histogram is now more centred and we have not gained any noise in the dark areas.

Nice tip to remember when you are out shooting.  When in doubt, expose to the right but the ultimate goal is to still to get it right first time round by metering properly!

Until next time.

Gerry