A portrait of the bearded Crassula (C. barbata)

It would be hard to come up with a more apt name for this interesting little gem which is not just beautiful, but also interesting in an ecological sense.
The following pictures show how dramatically the appearance of the plants changes between late autumn and late spring. Please bear in mind that the plants occur in the southern hemisphere, and also that they only grow in the cooler and wetter months (autumn to early spring). They  are almost always found in shade, under shrubs or rocks.

Crassula barbata
Mid May (late autumn)

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Late May

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Early August

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Late September

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Early October

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End of  October (late spring)
Now that summer is approaching, the rosettes have closed to minimize transpiration.  As a result of this, the cover of long hairs at the same time acts as insulation against strong light and desiccating winds.

Quality and direction of light in plant photography

As you probably know, photography means drawing (or writing) with light. Simply said: no light, no photography.  In this post I’ll describe two important  aspects of light:

Quality of light usually refers to its degree of diffusion, i.e. how  harsh or soft it is.
We tend to think that a clear sunny day is ideal for photography. As we will see, in reality it often gives the worst possible lighting, especially for taking plant  pictures.
A direct light source, such as the sun in a clear sky, produces harsh, contrasty light . The highlights and shadows are strong , resulting in big contrasts with abrupt transitions. This hard light also tends to make colours weaker.
Our eyes can cope with this kind of light much better than the camera, so that what looks acceptable in the viewfinder often turns out useless once it is photographed.
When the contrasts between light and dark are too big, many details will be lost, either in shadows or in washed-out areas. You may therefore have to use a diffuser to soften harsh sunlight and/or a reflector to get some light in a dark spot.
Hold the diffuser as close as possible to the subject. If you hold it further away, it will just throw a shadow on it.

clip_image002This picture was taken in harsh sunlight and is therefore very contrasty.
Even after spending quite a bit of time enhancing it in post-production, this was the best result I could get.

clip_image004This photo of the same species was made on a bright, overcast day, giving a much more pleasing result, even without any enhancing.
Using a diffuser on a sunny day would have yielded a similar result.

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In this pair, the differences are rather more subtle. The first picture was made without doing any special; for the second one  I used a diffuser.
Although I like both of them, the first one reminds me more of the hot and sunny day on which it was made. Therefore it also gives a better idea of the conditions  these plants have to cope with. 

In many cases the sensible and careful use of flashlight may also help. If none of this works, you will have to decide what is more important to you: preventing the highlights from becoming burnt-out or the dark areas from turning completely black. The first option is usually best.
On bright overcast or misty days the light will be soft and diffused, with shadows evenly scattered around the subject. This kind of light produces soft contrasts and is easy to work with. It is very pleasing for photographing flowers. However, sometimes you may have too much of a good thing and end up with light that is too flat. In such a case, it is a good idea to add some shade to a small portion of the picture or alternatively to highlight another part so that it stands out more.
Reflected light is often soft too. Completely overcast days with heavy, dark clouds are not so good for flowers, but may work well for other parts of plants.

Direction of light refers to the camera position with regard to where the light comes from. There are three primary directions of light: front, side, and back. They all have their own characteristics and exert different influences on the mood of an image. Depending on your subject you should try different kinds of lighting to see what effects you like best.

When the light comes from behind you and falls directly on the front of your subject matter, we talk about front lighting. The entire subject is evenly lit and the shadows mostly fall behind the subject, so that this often appears lacking in volume and texture. In close-up photography this type of light also may cause problems by the lens or lens shade throwing a shadow on the subject.

Back lighting is the opposite: the light comes from behind your subject matter; it emphasises shadows and outlines shapes strongly.

clip_image006Back lighting can produce striking pictures, especially against a dark background

It creates strong contrasts and can produce a bright outline around the subject. Like side lighting it can make the colours of translucent objects sparkle. It is most effective with translucent or strongly coloured leaves or flowers. It may be necessary to underexpose 1-2 stops in order not to overexpose the bright areas; on the other hand it is sometimes advisable to open up 1-2 stops in order to allow detail in the subject. Therefore this is one of the situations where you should bracket your exposures.
Back lighting is not an easy light to work with, but it tends to create a strong mood and can produce images that are hard to ignore. Both side lighting and back lighting normally occur when the sun is low on the horizon (early in the morning or late in the afternoon). When you can photograph a plant from underneath, you may get the back lighting effect at other times of the day as well.

Side lighting is best for showing texture, as it gives the picture a 3-dimensional quality.
There is a clear separation between the light and the dark side of the picture. The shadows produced by side lighting may or may not be useful in composing your picture. Like back lighting it can make the colours of translucent objects sparkle.

clip_image008Because the light is coming from the side, we see not only the tiny dewdrops, but also their shadows on the leaf

External water storage in succulents

The great majority of succulents stores water in stems, leaves and/or roots. Some of them however, mainly members of the  vygie family (Aizoaceae) also make use of external storage. They  have an epidermis covered with extremely enlarged and swollen cells (so called bladder cells) that are able to store water. Amazingly up to over 50 % of the total amount of water stored by the leaves can be located in these cells.

The cells have another advantage too: they are so big, that they create windless spaces above the stomata (breathing pores) so that transpiration is reduced. When a plant start suffering from drought stress, the cells collapse. This obstructs the passage of air to the stomata, so that water loss is reduced even further

droscfbrev2010_09_09#189_lznres One of the best known examples is the genus Drosanthemum (“dew flower”)

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Mesembryanthemum guerichianum

In this species (Mesembryanthemum guerichianum), the bladder cells are especially big on the calyx

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Phyllobolus nitidus is named for its shining appearance (nitidus = glossy, polished or shining)

Exactly the same, but different; what post-production can do for your pictures.

A couple of months ago my wife and I were travelling to our farm near Matjiesfontein when we decided to have a short coffee break. As usual, I utilized this opportunity to quickly scan the area. Not far from the road I came across a plant of Cotyledon orbiculata (the beautiful form that used to be called undulata).

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This picture shows my first attempt of photographing the plant.
It is not a bad photo, but neither does it convey the feeling I got when looking at the subject.

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After cropping the picture this is what I got. Much better I thought, but too realistic.

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Cropping in a slightly different way, combined with darkening the picture and enhancing the colours, resulted in this.
It seemed to me I was on the right track, but now the left side of the photo was too busy and distracting.

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I had also made another picture, almost identical to the first one, but taken from a slightly different angle. When I closely compared the two, it became clear that the second one would be the best starting point for the picture I wanted.

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I first treated the picture the same way as in number 3 and the lowered the contrast.
This is the end result, realistic enough to be of botanical value, but at the same time visually stimulating.

Water recycling in succulents

The editor of “Veld & Flora” ( http://www.botanicalsociety.org.za/)  invited me to write an article on succulents for the magazine. It is now ready and will be published in the March issue.
The article is called “Miniature succulents – masters of survival” and highlights some of the intriguing adaptations miniature succulents deploy in order to survive. The following snippet  will give you some idea of what to expect.

A peculiar adaptation is shown by many members of the mesemb family (Aizoaceae), especially the dwarf ones, which are able to recycle water from old leaves to new ones.
As the soil dries out towards the end of the growing period, the older leaves are gradually sacrificed and their water content is translocated to and stored in the younger ones. In this way, all available water reserves are concentrated in the last pair of leaves.
In the end, the dry remnants of the old leaves form a papery sheath acting as a protective layer of insulation for the new ones. When the next rainy period starts, the new pair reaches its final size and bursts through the old skin, ready for action.
It has been found that this adaptation enables plants to survive for about a year without any moisture supply from outside.

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These three pictures of Antimima pygmaea were taken near Matjiesfontein in winter (mid August), spring (early October) and summer (end of January) respectively. At first, it would be hard to believe that it is all one species.