The Colour of Light

We generally refer to light simply as "white" so can it actually have colour? Light is in fact a band of electromagnetic radiation of a type visible to the eye. Low frequency or long wavelengths such as radio or TV signals are obviously invisible to us. But as we increase the frequency or shorten the wavelength the radiation becomes visible, just below infrared, as a dark red colour. Increasing the frequency more we will descend through the colours of the spectrum, orange, yellow, green, blue and violet. Beyond violet we enter the realms of ultraviolet and the light dons it's cloak of invisiblity once more. At even shorter wavelengths we have X-rays and beyond that, Gamma rays. So "White" light is actually an equal blend of all the colours of the spectrum visible to the eye.

Exercise: Judging colour temperature Part 1

Using my pet tortoise Tony as a subject, principally because he was easy to position and wasn't going to run away fast, I took the first shot in midday sunlight.

With the white balance set to daylight this image much darker than it was in reality. Tony's shell does not normally appear to be as bright as that. And there is a definite loss of definition to his skin. I'm thinking the reflection of the sun off the shell may have fooled the light meter into underexposing.

For the next shot I moved Tony into a position shaded by trees but aimed in the same direction.

This is actually a more accurate rendition, certainly with regard to the skin areas. The shell looks washed out however and the definition is very flat.

I waited for the sun to start setting and then moved Tony to another part of the garden for the third shot.

With the white balance still set to daylight, this image almost appears to have been lit artificially. But the camera has recorded the event remarkably accurately considering the warmth of the light at this time of day. The areas of green certainly have a yellow tinge which was pretty much as it appeared during the taking of the shot.

Exercise: Judging colour temperature Part 2

Shooting similar scenes using differing white balance settings produced quite varied results.

Full sun Daylight WB

In this image of a wooden bust taken in full sun with white balance set to daylight, well it appears pretty much "as seen" The single colour has been rendered fairly accurately as has the background.

Full sun Shade WB

Switching the white balance over to auto has over warmed the image. Everything, including the background appears to be far too orange.

Full sun Auto WB

I expected the auto white balance setting to produce something similar to the first image. However it has arrived at an image sitting somewhere between the previous two but with an inclination to be too warm. I found this quite surprising.

Of the three images above I definitely prefer the first, shot with the white balance set to Daylight. The colours are much more true to life. I was quite surprised to see that Auto white balance produced a result that was far too warm.

Shade Daylight WB

With the subject moved into the shade and the white balance reset to Daylight I took this image. The subject appears quite cool. The background has been overexposed to it being such a bright day.

Shade Shade WB

The Shade white balance setting has brought the subject much closer to it's original appearance. 

Shade Auto WB

I think the Auto white balance setting has made a better fist of this than it did with the full sun image. But it is still too yellow. Again the best setting for white balance of this group of images has been the one deliberately specified for this particular lighting situation

I took the final three shots on another day in a different location.

Low sun daylight WB

Setting the white balance to daylight has produced a result that at first glance appears quite true to life. The low sun definitely provided a warm orangey glow to the scene.

Low sun Shade WB

This is quite interesting. I actually prefer this image with the white balance set to shade over the previous picture. The texture of the subject appears somewhat more refined in this version and the light a little softer.

Low sun Auto WB

Auto white balance has again revealed an image somewhere in between the previous two frames. I think it just errs towards the daylight setting. As before it is not my favourite image of the set.

This was a very revealing exercise. I tend to shoot somewhere in the region of 90% of my pictures with the white balance set to auto, for convenience more than anything else I guess. If this exercise is anything to go by, I've clearly been doing it wrong! I am quite honestly amazed at the difference when comparing the images side by side. I am also, quite honestly converted!


Exercise: Light throughout the day.

Wow, this was a difficult exercise, not due to demands of shooting but finding a location close enough that I could reach easily and having a successive run of days of clear weather. This was actually my third choice location as I had to shelve the aborted attempts at the previous two due to travelling practicalities. Eventually I ended up shooting out of my bedroom window across the valley. Not ideal obviously but I had to get it done.

Frame 1 0600

Frame 2 0700

Frame 3 0800

Frame 4 0900

Frame 5 1000

Frame 6 1100

Frame 7 1200

Frame 8 1300

Frame 9 1400

Frame 10 1500

Frame 11 1600

Frame 12 1700

Frame 13 1800

Frame 14 1900

Looking through these images again it's clear I could have chosen a better scene. Maybe I'll be able to amend it before assessment. The 1600-1700 shots are probably my favourites of this particular bad bunch. The shadows certainly add some depth. Generally I would say this particular view definitely looks best first thing in the morning but this has not been conveyed very well with this set of photographs.

Exercise: Variety with a low sun.

For this exercise I dragged a tacky holiday souvenir that had been given to me (honest!) outside just after sunrise.

Frontal lighting

I placed the jug on a fence post so that I could duck down and keep my shadow out of the frame. The subject has been lit very evenly with not a trace of shadow aside from inside the handle. Although the jug is of an orangey clay type substance, this has been accentuated by the warm colour of the early morning sun.

Side lighting

Leaving the subject in place but moving 90 degrees around it has produced this image. It's a 50/50 split of light and shade. The interesting point to note is the difference in the red on either side. In the sun it is seen as bright and fairly vivid. On the shaded side it has taken on a much deeper tone, more so as the jug curves round so that part of the red is farthest away from the light source.

Back lighting

Placing the subject precisely between the sun and the lens has produced this rather pleasing silhouette. Shooting at aperture priority with about 3 stops of exposure compensation it would have been possible to reveal some detail on the jug. This would have blown the sky completely of course. But I like this result.

Edge lighting

For this exposure I moved round the subject so that a group of trees formed a dark backdrop. Then composing with the sun just out of frame but behind the subject we end up with the "halo-effect" of rim lighting. Because we are still shooting into the light there is quite a pronounced lack of detail in the surface of the jug.














TWILIGHT

It would be fair to say that I haven't taken many twilight photographs, a real mistake on my part given some of the beautiful scenes I've come across along the way.

This image was captured after the sun had set behind me. Perhaps it's a little too late for twilight? But it seems to be not quite dark yet. Perhaps we can call it post-twilight.

This is quite a dark twilight shot. I like the way that the long exposure has given the water a silky smooth look and shows the movement of the clouds.

Again taken with the sun having set behind but with incandescent light on the subject. I like the mix of ambient and artificial light in this shot.

An early morning scene shot against the light. Heavily overcast skies have made for a not too pleasant effect.