The design of log curve

Before the article……

There are a lot of popular tutorial on how to expose with which camera on Youtube and all kinds of review websites. Long tiem ago before I learned all necessary things I’ve seen massive similar articles and video tutorials. The more I read and the more confusion I had. There are a lot of “Should” but nobody explains “why” so it becomes a mystireous topic and then people invented ETTR.

1. What is log and why we need to shoot log?

Nowadays, nearly all cameras are digital. The light signal comes from the optical parts will be sensed by the image sensor and that will be converted as voltage. Between 0 and maximum voltage the voltage shows the lights LINEARLY. Then the analog voltage will be converted to digital via AD convertor and read out to the processor. The processor(ISP) will process the data and then compress with codec and then store to mediums. This is the simple explanation of how the lights are finally stored to your disks.

2.What’s the important infomation we should know with log?

So for log design, the MOST IMORTANT infomation is how it allocate the lights: how many stops above middle grey and how many stops below it.

3. how to start testing your camera with log?

The first thing is you should get a grey card and expose it to the designed level and check the LUTs or the designed workflow(for Zlog2, please try our plugin).

Founder of Z CAM