Sciencemadness Discussion Board

Colour References

Sulaiman - 16-1-2016 at 23:31

As many of us use cameras that auto-everything (focus, exposure, white-balance etc.)
It is not easy to accurately compare colours or densities of solutions / crystals etc.
So we could put the SM logo in the photo, but we all have different printer inks, lights etc.

Would it be worthwhile having 'standard' coloured solutions in the photo?
e.g. 0.001M methylene blue, 0.1M CuSO4 etc.
If worthwhile, what solutions should we use?
I know virtually nothing about spectroscopy, but I think that some members may have good suggestions,
e.g. monochromatic, stable vs. temperature, atmosphere etc.

The basic idea is to have 2,3 or 4 test tubes of stable reference colour and density in all photos that we submit,
to allow direct comparison of results.
(ideally, future aliens could colour-correct our images)

Or has this been done already ?

OR
if someone can print pantone true colours
they could print the SM logo in true colours
(maybe modified a little to accommodate colour/brightness bars)
and we could buy copies.

crystal grower - 17-1-2016 at 05:16

very good idea.
I personally think that printed color spectrum would be the best.
Or maybe a CD ?

Etaoin Shrdlu - 17-1-2016 at 09:08

You want what is known as a gray card. This is shot along with the scene, then white balance and gamma can be adjusted so it looks as it would under a perfectly neutral light. Having a white and black card in the scene also helps getting the highlights and shadows correct.

Problem is this will not fix metamerism. The light spectrum is continuous, but cameras capture only three stimuli. This means under different lights the colors of different objects will shift relative to one another. So in order to ever really get close to a true comparison one would also have to shoot under the same light source.

chemrox - 4-2-2016 at 14:02

Since the spectrum apprehended is continuous how does the digital aspect come into play? Good information my friend, thank you!