Underwater RAW footage VS color graded
This is not meat to be a definitive guide to underwater color grading, just a few quick and dirty tricks and tips; a starting point ! It also serves to give example of RAW vs graded underwater footage.
When I started filming underwater I was shooting to tape or film. This allowed very minimal changes and color correction to be adapted in post. You would set the camera and even trick the camera by white balancing through strong colored filters; reds and magenta's to push the color back into the image as it was being recorded.
Now with the onset of 4K and higher resolutions many digital cinema cameras like the RED Epic / Weapon that I operate; you now have the ability to shoot everything in RAW, increasing the amount of information in the image that you can later adapt in post.
A good color grader in post can make all the difference, and when dealing with a show that includes underwater footage it always helps if the person is a diver or has been underwater. You would be surprised the number of shows that either don't have the budget for a color grade or will just add a blue or green wash over everything.
When I first started shooting in RAW I was initially surprised by how dull, washed out
and drab the footage looked. See the right hand side of the image. It was not until I started learning about color grading that I realized the advantages of shooting in RAW. In a nutshell it is basically like photoshopping the image. It also provides you with an amazing tool to keep color continuity between shots.
I took this video whilst I was the underwater cameraman for 'This is my PADI Story - Mike Coots, Shark Bite Survivor and Advocate", for PADI. (Click HERE to see the full video). The site at Tiger Beach in The Bahamas is shallow, around 15-20ft and when the sun is shining there is plenty of natural light penetrating the crystal clean water and bouncing off the white sandy seabed. I shot everything in RAW, with neutral values, on a RED EPIC at 4K HD, offspeed at 60fps on a 30fps base rate project, using a Nikon 17-55 f2.8 lens.
As you watch the video you can see the original RAW footage looks very washed out, minimal contrast and greeny / blue, with no color depth. The graded version has much more color depth, contrast and saturation, for ease of example I pushed everything a little higher level than I usually do and bumped up the saturation. There are many ways to go about doing this depending on your camera, format, operating system and editing program but here are a few tips that may help get you started. For post I use RED CineXPro and Adobe Premiere Pro to edit and do quick grades.
Some Quick and Dirty Rules and Tricks for Underwater Color
1. Every different body of water has a different color to it so your grading settings may vary between bodies of water.
2. Depth also affects your grading as it changes the amount of red appearing in each shot as well as the light intensity.
3. Visibility; the cloudier the water the bolder your blacks and the less contrast you have underwater as well as reduced light levels.
4. At the basic level change the white balance, color temperature of your footage, add more warmth back into your shots.
5. Remap your LEVELS - In a nut shell pull and push the dark areas towards dark pixels
and the remap light areas to light pixels. The central Point is Gamma and you can adjust that level to personal taste. These immediate changes should make image pop more and provide the image with some depth but no color contrast. Remember to crush the blacks.
6. There are few ways of achieving this same goal however one of the easiest on Adobe Premiere Pro is a tool called 'Selective Color" - a way of adjusting colors based on primary and secondary colors.
You can adapt the color and increase the color depth of the image by selecting the color / area you wish to grade. (Think of it like layers in Photoshop). You can do this by adapting the main Red, Yellow and Blue and additionally Cyan, Magenta or Yellow. If you try and adapt the red in most underwater images nothing is likely to change due to the lack of red light penetrating underwater, unless you are really shallow.
Most RAW underwater images will have greeny blue tinge to them, this is your cyan.... Select magenta (the opposite of cyan) and add increase the levels to taste. Whilst gently going negative with the cyan levels, (basically adding red back into the footage).
Keep adding selective color layers to build up the appearance of the shot until you are happy. You can then copy and paste this grade to some of the other clips you shot in that sequence.
Color grading is not an exact science and I by no means claim to be an expert! These are just a few tricks I have learnt along the way that helped me and hopefully may be of some use. There is no compromise for a professional grader and editor but you can really get much more out of your footage with some of these simple tricks. Have fun and play around with it !