A Guide To Visual Effects

If you want to know anything about how visual effects in film and video are achieved, there’s one word you should keep in mind…layers. All visual effects and optical illusions are constructed on the bases of images layered on top of each other. Before the advent of computers, visual effects were achieved by placing paintings in front of the camera, appearing on top of the action in order to create bigger and more fantasized locations. Another method was to reprint two layers of action into one single image to create an optical illusion.

matte

As technology advanced, filmmakers perfected methods to composite images together to create optical illusions. These advances came with the advent of motion controlled cameras and chroma keying (also known as blue or green screening). The ability to remove a single colour (blue or green) from one image, and replacing the colour with another image.

before-after-green-screen

We’re now in the digital age, we use computers for nearly everything, and so do filmmakers. Computers are now used for compositing images for optical illusion. They’re also used to create computer generated images. The most recent advancement is motion capture technology, giving a performer the ability to give life to a computer generated character. Whatever the method, the images created are always layered and composited from a range of sources to create a visual effect.

Lord Of The Rings Two Towers: the character Gollum who's role is crucial to the journey of Frodo and Sam--Gollum's movements are performed via computer program by actor Andy Serkis.  Photo: New Line Cinema
Lord Of The Rings Two Towers: the character Gollum who’s role is crucial to the journey of Frodo and Sam–Gollum’s movements are performed via computer program by actor Andy Serkis. Photo: New Line Cinema

Are you thinking of creating a visual effect for your film or video and unsure where to start? Then here’s my advice. Start by drawing the shot you’re trying to create. Now break it down into sections, this could include location and background, performers, and anything else that is moving in your shot. Think about what sections of the image you are definitely able to capture in camera on a one to one scale. Now think about the sections of the image that are more of a challenge to capture in camera. Could you use miniatures, puppeteers, animation and/or computer generation? It’s in this section where blue or green screening becomes an effective method of separating your elements and compositing them together into one image.
Things to keep in mind when creating your images are the lines between where one section of your image meets another and the one to one scale elements you can not miniaturize which are light, water and fire.



A Guide To Colour Grading

Before continuing with the subject of this article, I would like to acknowledge that the reason this article has been long over due is to the amount of exciting work that has been happening recently. There will be some case study articles to be released in the days to come and I cannot wait to share the behind the scenes info with you. Now onto the subject of this article, colour grading.

Colour grading is a post-production effects based process for your film or video project. The creative process of your project means having complete control over the look and feel of your images, colour being a part of this process.

Before continuing with this article, let us take a step back to something I mentioned in my previous article on The Guide to DSLR Video…The Picture Style. The picture style is the final outcome of what you are filming, and the information you can work with in your editing suite. In this article I will specifically talk about what you can edit when it comes to the information of light and colour captured in your images. This is why the Neutral Picture Style or the Technicolor Picture Style is a popular use among camera operators, because the style provides a dynamic range of image information to correct and adjust afterwards.

colorgrading

Primary Colour Grading

The first thing you want to make an adjustment to is what’s called the primary adjustments. This is the actual correction part of the process, making sure the light is balanced. In colour grading tools, a histogram should be visible, to aid you in making these adjustments. I always find starting with the dark areas helps. For dark areas you want the bottom peak of the information in the histogram to just touch the baseline. Then with lighter areas, you want the peak of the information in the histogram to just about touch the 100 line. There will always be some overexposed areas with the whites, so it doesn’t have to be exact. Have the video showing to make sure it looks correct. As an extra tip, I find making the image black and white helps as a guild to getting your definitive contrast between light and shadow, and then restore the colour afterwards.

Don’t change colour saturation until you are ready to move onto the secondary colour grade. The last thing you need to do before moving on to this is to correct any colour balance issues. Is there too much of a singular colour in your image, is it too green or blue. Using the three colour wheels in your toolbar, make adjustments to balance the colours in your image.

Secondary Colour Grading

Now that your image has been corrected, it’s on to the secondary adjustments. This is the aesthetic process of your colour grading, the design of how your image is meant to look and feel. Let’s look at your image as a whole, how colourful do you want it to be. Colour grading also has an emotional effect over your audience. Desaturating the colour will give an expression of sadness and gloom, where as high saturation in colour can uplift the mood of your audience.

Now I want you to break down your image into every single colour that is there. Which ones do you want to be more saturated and which ones do you want to be less saturated, or not in there at all. Your colour grading tool can allow you to achieve this. Using a mixture of markers, geography and colour wheels, you can manipulate your image to get a balance of the only colours you want in your image.

In summary you can make the colour in your film or video look the way you want by:

  • Balancing the light and shadow in your image.
  • Correcting the reds, greens and blues in your image.
  • Making changes to the saturation in your image.
  • Break down your image into objects and their colours, which ones should change and be enhanced.