To draw these shadows 'only' darker with a contrast control can end in a nasty surprise.

With the S-Log formats, the maximum underexposure is 8 f-stops. The log formats, however, contain the darkest image information that the sensor could see in the shadows. The usual contrast effects of editing programs were designed for editing with Rec709.

This example alone already shows that the contrast control will not produce the same result with both variants or completely different log formats. With S-Log2, however, the correctly exposed gray card is somewhat lower, namely at 32%, i.e. This is where the normally exposed grey card is at S-Log3. This mean value can be observed and determined with a waveform monitor or a histogram.Įxample: The software Sony CATALYST BROWSE sets this average value at about 40 % brightness. Usually in the editing program a usual contrast effect raises the image parts above a certain mean value and lowers the shadows above this mean value. The log recording contains - as we could see in the past issues - for example in S-Log2 and S-Log3 up to 14 f-stops contrast range. On average, the usual plug-ins for contrast, brightness and saturation seem to be suitable - but the first 'LOG trap' is already lurking here. The image, which at first is still far too low in contrast, must gain contrast and saturation and obtain the gamma curve typical of TV. In the TV sector, the goal is initially Rec709 (ITU Recommendation BT.709) for HD - in the future this colour standard will still change (BT.2020). In artistic grading, contrasts and colours are changed according to individual wishes and artistic demands - and they can be very different. In technical grading, the first step is to create a high-contrast image with correct colors from the low-contrast and unsaturated log images. Colorgrading, contrast correction, color correction - I differentiate between 'technical' and 'artistic' grading:

Sony luts log