Diffuse lightingOpenGL

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Welcome to my blog based on my life as a biologist turned peripatetic wildlife photographer/writer to 50 countries – 32 visits to China alone – over four decades.

Diffuse lightingideas

Image intensification night vision devices work by collecting available light through an objective lens. The collected light then passes through an image intensifier tube, which amplifies the light photons. The intensified image is then displayed to the viewer through an eyepiece.

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There is no better way of appreciating just how effective a diffuser can be at reducing high contrast and strong shadows than by taking comparative shots with and without one. Carrying a diffuser is the equivalent to having your own portable miniature cloud for use on sunny days.

Diffuse lightingPhotography

So, while night vision devices can utilize low levels of infrared light present in the environment, they cannot directly see or display the full infrared spectrum. For applications requiring the detection and visualization of infrared radiation, thermal imaging cameras or specialized infrared cameras are more suitable.

Night vision devices, specifically those based on image intensification technology, cannot directly see infrared (IR) radiation. Night vision devices (like a night vision phone) enhance existing ambient light, including visible light and low levels of infrared light, to provide improved visibility in low-light conditions.

Diffuse lightingfor home

Unlike the chestnut coloured conkers produced by the European horse chestnut (Aesculus hippocastanum), those of Indian horse chestnut (A. indica) conkers are dark brown. They were discovered lit by strong sunlight, when the texture within the deep tones were lost by the conspicuous catchlights from the sun. So a diffuser was used to even out the light and eliminate the harsh shadows.

The first pair of images feature a crocus. On the left, the flower is spotlit by sun beaming through trees at 4:10pm in March. The result is a dramatically lit flower emerging from its surroundings completely in shadow with no hint of the adjacent plants. When a large Lastolite Tri-grip diffuser was held between the sun and the crocus, this dramatically reduced the contrast (and the light level by two stops). Whenever a diffuser is used, the light needs to be re-metered with it in position. The exposure for the first shot was 1/30 sec at f/18 and, with a diffuser, I retained the same aperture and changed the shutter speed with an exposure of 1/8 sec at f/18.

Diffuse lightingled

The aperture was kept constant for both shots at f/11. In sunlight the ISO was 160 and the exposure 1/400 at f/11. With a diffuser used for the right-hand shot, I pushed the ISO up to 400 and the exposure was then 1/250 at f/11.

While image intensification night vision can enhance low levels of infrared light that are present in the environment, it cannot detect or display the full spectrum of infrared radiation. These devices primarily rely on the visible light spectrum, and their performance is limited in complete darkness or environments with minimal ambient light.

These three comparative pairs show how dramatically diffused light can change the appearance and mood of a close-up subject.  By experimenting, you will soon appreciate that some subjects work fine when lit with direct light, while others are enhanced by diffused light.

The second pair of images was taken in Chile and shows one of many terrestrial Chloraea orchids, which are typically white and green, with some yellow and green species. This one is Chloraea volkmannii.

Diffuse lightingexample

I am often asked what is my favourite lighting. Since no type of light suits all subjects, I don’t favour any particular one. However, soft diffused light gives stunning results for many flowers – especially pastel-toned ones; whereas direct sunlight is good for bold reds and oranges and creating shadows that can add a dynamic element to the composition.

Growing in a meadow bathed in sunlight, the left shot is as found with the sun shining directly on the orchid and the grass behind. By using a small diffuser to block out the sun falling on the orchid only and not on the background, resulted in an enhanced tonal variation of light reflected from the two. The background appears brighter because I had to re-meter the flower and adjust the exposure. This can be a useful way of separating a subject which has a similar colour and tone from the background – notably grasses against green vegetation.

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Diffusedlightinginterior design

The second shot is more restful to the eye. It also more informative since it reveals the ground beneath the crocuses is carpeted with attractively patterned cyclamen leaves.

On the other hand, thermal imaging cameras (such as a thermal imaging phones), which are different from image intensification night vision devices, can detect and visualize infrared radiation. A thermal camera operates based on the detection of heat signatures emitted by objects, rather than amplifying existing light. They are capable of creating images or videos that represent variations in temperature, providing a clear view of objects based on their thermal emissions.