34 Tungsten and fluorescent lighting

This exercise is designed to explore the properties of Tungsten and Fluorescent lighting. The first part of the exercise did not involve a camera, just the human eye, in an experiment to see if we were able to see the colour casts the the camera can.

First towards dusk I stood in the room with the tungsten lights on, standing by the window looking out into the garden for a few minutes, then I turned to look into the room, which now looked yellow. Then in continued to look in the room for a few minutes then turned back to the window and the garden scene now looked blue. The yellow of the tungsten lights is also quite obvious when walking in the dark and observing house lights from afar.

The second part was more typical asking for a photograph showing a tungsten lit interior, with a window visible towards dusk. These were to be taken at daylight, auto and tungsten white balance settings.

The third part was to find two locations using fluorescent lighting and compare images taken at auto and fluoro white balance settings and compare the results. It was also noted that fluorescent light does not produce a full spectrum illumination, as a rule the older/ cheaper lights typically have a strong green cast but these lights have no standard and can vary considerabley.

Equipment used Nikon DSLR, 28-300mm lens and tripod. Image processing Nikon NX2 and DXO.

Tungsten and daylight

Daylight white balance

_DSC5484_2_DxO

On daylight white balance setting you can clearly see the heavy yellow cast from the tungsten lighting, but the view through the window has no cast.

Auto white balance

_DSC5484_1_DxO

On auto white balance the sensor can clearly see the opposing colour temperatures and has tried to balance the resulting image. But now you have a yellow (less than daylight white balance) in the interior and a blue cast of the exterior, which in this case is probably the worst of both worlds.

Tungsten white balance

_DSC5484_3_DxO

On tungsten white balance the interior is now the correct cream colour, but of course the daylight outside now has a heavy blue cast. Assuming this is where the subject is this would be the better setting and avoid the window in the shot or close the curtains. If you need ped to balance the interior and exterior colour balances my preference would be to use flash to light the interior, which is daylight balanced.

Fluorescent only

Scene 1 small CFL lamps – for this shot I replaced my tungsten bulb with a very cheap CFL one.

Auto white balance

_DSC5491_1_DxO

Fluoro white balance

_DSC5491_2_DxO

Scene 2 older strip lights – real old style fluoro lights in my garage.

Auto white balance

_DSC5486_1_DxO

Fluoro white balance

_DSC5486_2_DxO

In both the CFL and the old Fluoro tubes the auto white balance of the camera has produced a warm result and the Fluoro setting has attempted to produce a more neutral image. But in both cases has produce a cool blue/green image and the cheap CFL lamp image is clearly lacking in colour.

That all said there are a number of elements that are not clear, the type of lamps used I could not determine, as there appears no standard to these lamps and the more I read, the more I realise that they can produce very mixed results depending on their colour temperature and range, which may not even be continuos.

Plus my camera has many fluorescent options and can also be set to white at almost any colour temperature, so clearly I need to do some more work to understand these options. If I then add the complexity of options if I shoot in RAW these increase again in the image processing options available.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s