Natural light question.

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Hi
I would like to photograph a piece of material and use it as a background for a number of images, not all at the same time.
How do I achieve Natural lighting so the image looks similar or true to the material as possible.

Is there a photographic standard for natural light.

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You may find an overcast sky gives a smooth light suitable for the purpose you have in mind. A similar light can be created by using bounce flash off a whitish surface.

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A complicated issue that touches upon many scientific and philosophical issues–first and foremost, how you would define “natural”? I think this is your central question that you must answer for your own purposes. Others may disagree. There is more than a bit of subjectivity here.

Is “natural” light what one experiences at midday on a sunny day in summer? In winter? In late afternoon light? Cloudy light? Is firelight or candle light natural or unnatural? Philosopher Alan Watts once asked whether perfectly still water reflects light more naturally or correctly than turbulent water. Is one more “natural” than the other? Why?

If you take natural to mean mid-day in summer (or thereabouts), then you are likely going to need an overhead, uniform, broad-spectrum source near 5200K–avoiding fluorescent, LED and other types of lighting with narrow emission bands. Of course, intensity, exposure, post-processing, and your own perception also figure into this greatly.

Slainte! (from a fellow Irishman, albeit many miles from the homeland)

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I’d say daylight, because it presents the most even energy distribution of wavelengths of the visible spectrum.

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Slainte from the owld sod, Kadsura

I think Terry, Glenn and yourself, summed it up nicely.
Its subjective and should be averaged.

In a practical way, I’ll take the shot around midday with no direct sunlight hitting the material and try to keep it evenly lit across the material which is natural slate (W=600mm x H=300mm).

That forms the background colour and I’ll then photograph the colour samples (dithered, lasered test squares at various power %'s) at the same time and position.
Then use those luminosity values within the slate colour background.

I’m trying to create a screen view of how an image will look after completion.

The test squares are each mesured for luminosity and the greyscale photo/image tonal range can be adjusted to match the output range of the laser without clipping.

Thank you all.

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I would just use color calibration to adjust the white balance to what I want.

Yes, I would make a bad philosopher… to practical :wink:

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Thanks Tames, I didnt know there were so many variations of colours esp Blacks.

I realised pretty quick that black and grey tones would have to be seperater into micro-contrasts…its essential for laser engraving. In head and shoulder shots, the shadows under the chin or where the hair meets the face and neck were becomming hard to keep from being crushed…and also skin tone.
I think the camera and rawtherapee may save the day, or at least a lot of time and a fairly acurate way of constructing a preview will help.

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