I am playing with the different picture styles directly from my Canon 5D-II and I would like to know if there is some sort of mapping with what I can do in Lightroom.
What is the equivalent of -2 contrast in Lightroom?
What is the equivalent of +1 saturation in Lightroom?
There is no equivalent. These scales are completely arbitrary and not measured in any unit! There are no step sizes and no real limits, for example:
Some cameras let you go from -2 to +2, -5 to +5, 0 to 9 or even non-numeric scales like high to low.
Note that these parameters are subject to interpretation. For example, there are dozens of ways to sharpen images and software differ in the algorithms they use. Even something like Contrast is not 100% defined and may be done in different spaces.
Since it will vary from camera to camera, the easiest way to find out what the equivalent is for a specific camera would be to test it yourself. Set the camera up as neutral as possible. In the case of your Canon 5D Mark II, that would be the 'Neutral' picture style. Then take a series of RAW+JPEG photos with the contrast set at -4 to +4 in one step increments. Then compare the results of the in-camera JPEGs to the RAW files in Photoshop Lightroom with -2 contrast applied. You can do the same thing with saturation.
One thing you should realize is that the in-camera contrast and saturation settings have no effect on the RAW data from a file when opened in Lightroom. If you have Lightroom set to display the JPEG preview embedded in the RAW file while the RAW data is being processed, then those setting will obviously be visible while the preview image is being displayed. Once the RAW data has been demosaiced the Lightroom profile you have selected determines how the image is displayed based on the RAW data. The same scene taken with the same ISO, shutter speed, and aperture and saved as RAW files will all appear identical when the RAW data is displayed in Lightroom using the same Lightroom profile, regardless of what Picture Style and amounts of Contrast, Saturation, and so on were selected at the time each shot was taken.
The JPEG images produced in-camera use the settings you have selected and apply them to the RAW data before outputting the JPEG file. Also be aware that different Picture Styles for your 5DII have adjustments to the baseline amount of things such as Contrast and Saturation already built in. For instance, a -1 saturation setting in the 'Standard' picture style is still a higher saturation than a +1 saturation setting with the 'Neutral' picture style. But all of that only affects the photo when the in-camera processing is applied to create a JPEG. The only way to see the difference in in-camera settings for things such as Contrast and Saturation with a RAW file is to open them with an application that reads and applies the in-camera settings when displaying the RAW file. One such program would be Canon's Digital Photo Professional.
