Sunday 26 September 2010

Tungsten and Florescent Lighting

Exposure readings with an ISO of 100 and an aperture of f2.8 suggested a shutter speed of 1/60 to 1/100. At the latter speed I can just about use the camera hand held but experience tells me that anything below 1/125 is a gamble that usually end unsatisfactorily. Wherever possible I will use a tripod and where this is not practical I will increase the ISO as far as possible without sacrificing the quality of the photograph.

The following photographs were taken when I judged that level of light internally and externally was about the same.  Not easy.

Camara set to Auto White Balance

Camera set to 'Daylight'

Camera set to 'Tungsten'

Of the three images the one taken with the camera set to 'Tungsten' gives the closest match to the colours as seen in normal daylight. The 'daylight' shot is far too orange overall whilst the 'Auto' although acceptable still retains an orange cast.

For the second part of the exercise the first pair of shots was taken in a room with CFL lamps providing the lighting whilst the second pair was taken in a room lit by fluorescent strip lighting.

Camera set to 'Auto'

Camera set to 'fluorescent 4000k'

The first image of this pair seems almost right although there is a blue cast to the image that is shown in the ceiling of the bay window. The second appears to be too 'warm' with a slight orange cast to the walls and the ceiling above the lights.

Camera set to 'Auto'


Camera set to 'Fluorescent 4000k'

Whilst both pictures lie within an acceptable range neither are quite right. Of the two the one with the camera set to 'Auto' is the closest to our normal perception.

The temptation here was to adjust the colours in photoshop which would have made the whole exercise worthless. It is perhaps too small an example to make any judgement on the best way forward when faced with artificial lighting particularly as fluorescent tubes can offer a wide range of temperatures but leaving my particular camera on 'auto' seems the best option.





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