articles/Software/grisnik-page3

Getting to grips with Nik's Software - part 3 of 1 2 3 4

by Mike McNamee Published 01/12/2009

grisnik-05.jpg

ABOVE:

This graph has been published before but will bear a repeat explanation. It plots the hue and saturation values of human skin (almost all races and ethnicities) at a constant 60% Lab Lightness value. It is a Lab plot, red to green along the horizontal axis, yellow to blue down the vertical axis and, because skin is mainly red, only the upper right quadrant of the graph is shown. The radial lines are constant hue (colour) measured in degrees around the colour wheel. The contour lines are constant saturation - zero at the graph origin (ie no colour = neutral grey) and progressively more saturated as you move out towards the upper right of the graph.

Analysis of Aled's Nik-ready files shows that he has slightly lifted the saturation and that, most importantly, he has pegged back his highlight values to 237RGB points so that the Nik filters have something to work on. This can be accomplished with the original exposure or by pulling up the 'recovery' slider in the ACR interface. Although Nik filters have a highlight slider in order to recover some of the highlight burn out, the default setting can lose a vast amount of detail and so effects have to be carefully painted in to avoid this, a problem that newcomers to the filter plugin seem to have trouble with.


grisnik-06.jpg

Afro-Caribbean complexions lie on the graph almost alongside the Caucasian values, the only difference is in the lightness value (the dark brown ellipse). The average for Caucasian skin (Lab 14;17) is shown by the skin-coloured star. The averages for newborn infants (1,500 measurements) are located below and left of average Caucasian ie more pink - babies are pink! The Chinese races are rotated towards yellow (Emily is a Chinese girl), the Asians are normally located slightly more yellow and more saturated than Caucasians and may or may not be darker in Lightness value, the variations overlap. The black star shows the values that Aled (and previously Martin Sellars) place their Caucasian female models in photographs, ie more saturated and very slightly more yellow ('tanned' in common parlance). The pink circles are the 'skin' values taken from the GretagMacbeth Color Checker SG. Your editor, red-haired of Irish descent is quite red and pale and only just makes it onto the graph!


Please Note:
There is more than one page for this Article.
You are currently on page 3 Contact Mike McNamee

1st Published 01/12/2009
last update 21/07/2022 08:46:24

More Software Articles



There are 0 days to get ready for The Society of Photographers Convention and Trade Show at The Novotel London West, Hammersmith ...
which starts on Wednesday 15th January 2025


Fast and intuitive, PortraitPro intelligently enhances every aspect of a portrait for beautiful results.

Update cookies preferences