It’s often not until you compare a correctly exposed shot with a slightly over shot that you see how the skin tones are becoming flattened out by the gamma compression.īut what exactly is the correct exposure level? Well I have always exposed Hypergammas and Cinegammas so they look 10 to 15% darker than a 709 image would. This can then make it might be hard to grade. Skintones will start to loose contrast and look a bit flat if above 70%. It might not be obvious in your footage, it might look OK. If you overexpose a face (by exposing it at 70% or more) then you start to place those all important skin tones in the compressed part of the gamma curve, at the start of the roll off. So instead of setting zebras to 70% for skin tones, you should set them to 55% to 60%. The correct exposure for skin tones with the Hypergammas and Cinegammas is around 55-60%. the range between the darkest shadows and the brightest highlights that the camera can record is greater, your exposure latitude is actually smaller, getting your exposure just right with hypergamma’s and cinegamma’s is very important, especially with faces and skin tones. It’s ironic, but although you have a greater dynamic range i.e. This them means you have much more space between 75% and 109% to record a larger range of highlights in a much more pleasing manner with a more gentle roll off.īut, this lower white level means you really need to watch your exposure. So with the Hypergammas and Cinegammas we bring the white recording level down to between 70 and 75%. That really isn’t much space for a bright sky, shiny cars or lots of highlights. That only leaves the space between 90% and 109% (or 100% if the clip point has been set to 100%) to record anything that is brighter than the white piece of paper. With Rec-709 we normally record white (a white card or white piece of paper) at between 85 and 90%. To get a greater dynamic range than normally provided by standard gammas the compression has to be more aggressive and start earlier. To get be able to record this greater range, the highlights are compressed.Ĭompression point with Hypergamma/Cinegamma. Compression almost always requires that you throw away some of your picture information and Hypergamma’s and Cinegamma’a are no different. If you want to squeeze more range into that same sized bucket then you need to use some form of compression. The problem being that our recording “bucket” where we store our picture information is the same size whether we are using a standard gamma or a more advanced gamma curve. To achieve these things though, sometimes compromises have to be made. With Sony’s Hypergammas and Cinegammas one of the key aims is to capture a greater dynamic range than is possible with normal gamma curves as well as providing a pleasing highlight roll off that looks less electronic and more natural or film like. When an engineer designs a gamma curve for a camera he/she will be looking to achieve certain things.
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