Colour Balance and Underwater Photos
The Pentax Optio S5i has a "marine" mode that sets the color balance for underwater photography.
Water filters out red light from the sun and so it leaves a blue cast. Depending on the sunlight, the water clarity, the depth and even which way you're facing impacts the level of blue.
Also, the deeper you go the more the other colours are filtered, until there's just blue.
The Optio has a marine mode that compensates for the reduction of red light - it's in effect a digital filter inside the camera.
It looks like the camera is geared more for shallow diving rather than deep diving. Also in close-up it works very well.
But on images that are a little further away there's still a colour cast. We've tried Video Pilot on some of our movies to reduce the cast. You can see the results here taken at Port Turton, Australia in a before-and after movie (reduced for web download).
One of the good things about this tool is that you can fix the cast up once for a movie, then use the "palette" to fix other movies taken at the same time and depth.
Another cool thing is that it's not just about white balance. Let's say there's a movie with me diving, and my hand is in view. I could find another image that showed my hand (or maybe my face) and take that "above-water" flesh colour as the basis of the balance - basically tell the program that the two images share the same colour palette.
We'll keep you posted on how it works on our upcoming scuba dive holiday.
Water filters out red light from the sun and so it leaves a blue cast. Depending on the sunlight, the water clarity, the depth and even which way you're facing impacts the level of blue.
Also, the deeper you go the more the other colours are filtered, until there's just blue.
The Optio has a marine mode that compensates for the reduction of red light - it's in effect a digital filter inside the camera.
It looks like the camera is geared more for shallow diving rather than deep diving. Also in close-up it works very well.
But on images that are a little further away there's still a colour cast. We've tried Video Pilot on some of our movies to reduce the cast. You can see the results here taken at Port Turton, Australia in a before-and after movie (reduced for web download).
One of the good things about this tool is that you can fix the cast up once for a movie, then use the "palette" to fix other movies taken at the same time and depth.
Another cool thing is that it's not just about white balance. Let's say there's a movie with me diving, and my hand is in view. I could find another image that showed my hand (or maybe my face) and take that "above-water" flesh colour as the basis of the balance - basically tell the program that the two images share the same colour palette.
We'll keep you posted on how it works on our upcoming scuba dive holiday.