Sorry, Brad... I added to my post as you were replying. FWIW, I agree with you.
Yeah, that was badly phrased.
Originally Posted by Q.G.
Filters can only darken, obviously.
But sometimes the effect is as if the object was lightened rather than the surround darkened. If you have more than two objects in the scene the distinction between lightening and darkening becomes real.
I judge filtration by comparing the results of the filter on the object against a grey card. Something that darkens the leaves would darken them in relation to a grey card - if the leaf and card have the same relative value and placing a filter in the light path doesn't alter the relationship of the filter to the card then in my book it didn't really darken the leaves. Conversely if the flower became brighter in relation to the grey card with the filter in place I think of the filter as lightening the flower rather than darkening the grey card or the leaves.
Lets say we have a scene of a flower, leaves and sky. In the prints the tonal value of the sky stays the same. If the relationship of the flower and the sky stays the same but the leaves go dark then I think of it as darkening the leaves because that's what it looks like in the final print. If the filter darkens the leaves and sky, passing the wavelength of the flower, then I think of it as lightening the flower - again, because that's what it looks like in the print as the exposure was increased to maintain the sky's (and in this case, the leave's) tone.
Science Vs art; reality Vs perception. Photography is the use of science and reality to make art and alter perception.
Last edited by Nicholas Lindan; 09-03-2009 at 03:27 PM. Click to view previous post history.
Thanks guys for the advice
I used to know the colour wheel stuff but as I haven't done colour in decades its all gone
I have some colour photography books in the attic gathering dust - which I cannot get to
The suggestion of Nicholas to compare the colour though a filter against grey card is a really great idea