How camera flash affects the colour of birds...
I've been looking for a Crimson Rosella in the sunlight to compare with the one I posted recently taken using on-camera flash - found this one during this week's outing.
On the left is a Rosella illuminated by sunlight, on the right is another one illuminated mostly by flash. The difference is perhaps as surprising (to some of us!) as it is repeatable and something that doesn't seem to get much discussion. Other photos of many parrots including other Crimsons show the same effect.
In this bird, greens appear under flash that aren't there with natural lighting, most of the purples disappear, and many other colours have a washed-out muddy look about them. The image generally looks strange. In other parrots some colours appear much brighter and more yellow so it's not always the same effect. Why is it so? I for one don't really know but my current theory is that it's a combination of:
a) on-camera flash is highly directional. Some colours in birds such as blue are so-called "structural" colours, meaning that the colour comes from interference effects of the microscopic structure of the feather, rather than from pigmentation. It is possible that structural color responds differently depending on the direction and directionality of its illumination.
b) fluorescence may change some colours since camera flash contains more ultraviolet than sunlight. I'm not convinced about its role here though, mostly because it affects more colours than the patches that have been shown to fluoresce on some parrots.
How camera flash affects the colour of birds...
I've been looking for a Crimson Rosella in the sunlight to compare with the one I posted recently taken using on-camera flash - found this one during this week's outing.
On the left is a Rosella illuminated by sunlight, on the right is another one illuminated mostly by flash. The difference is perhaps as surprising (to some of us!) as it is repeatable and something that doesn't seem to get much discussion. Other photos of many parrots including other Crimsons show the same effect.
In this bird, greens appear under flash that aren't there with natural lighting, most of the purples disappear, and many other colours have a washed-out muddy look about them. The image generally looks strange. In other parrots some colours appear much brighter and more yellow so it's not always the same effect. Why is it so? I for one don't really know but my current theory is that it's a combination of:
a) on-camera flash is highly directional. Some colours in birds such as blue are so-called "structural" colours, meaning that the colour comes from interference effects of the microscopic structure of the feather, rather than from pigmentation. It is possible that structural color responds differently depending on the direction and directionality of its illumination.
b) fluorescence may change some colours since camera flash contains more ultraviolet than sunlight. I'm not convinced about its role here though, mostly because it affects more colours than the patches that have been shown to fluoresce on some parrots.