Camera Profiles - What is Lightroom Changing

Trying to get a better understanding of Lightroom's camera profiles, I've been flipping through available profiles to see how each one changes the adjustment settings in LR5, but I've found no indication of changes to the adjustment sliders or tools that we photographers can make. I guess I thought the Profiles were like Presets, but all the controls remain set to 0 as in the original raw import. Apparently, I am thinking of this all wrong. So what are the Profiles changing behind the scenes and, more importantly, does one profile provide a different level of control over another. For example, if I select a profile with brilliant color, does my adjustment capability of colors differ than if I were to select a Profile with a little less brilliant color. In other words, does Profile A allow me to adjust from 75-100%, for example, while profile B allows adjustments from 60-85%.

The "Profiles" in Adobe Camera Raw (ACR) and Lightroom (LR) are Adobe's characterization of color and tone for your particular camera. They only apply to raw files, which need some instructions on how to form a color RGB image from the raw data recorded during image capture. The profiles are stored on your computer in the form of camera-specific "DCP" files. For a short history on the nature of the profiles, see for example this post from 2008:

http://blogs.adobe.com …r_whats_it_all_​about.html

You can make your own camera-specific DCP files, or edit existing ones, using Adobe's DNG Profile Editor:

https://helpx.adobe.co​m …hop/digital-negative.html

(scroll down to the Resources section)

Tutorial here:

http://wwwimages.adobe​.com …e_EditorDocumen​tation.pdf

The profiles that come with ACR/LR for your camera include Adobe's version of what they think is a good starting point for color (Adobe Standard) and their characterization of the Picture Style color (for a Canon camera, for example - Neutral, Faithful, Portrait, etc) that mimics the color for various JPEG picture styles.

These profiles are not presets of the sliders in ACR/LR, they are instructions on how ACR/LR converts your raw file into a color image, including color and contrast interpretation.

For more under-the-hood information on DCPs, see the dcpTool source forge page - dcpTool is a command-line tool written to make DCP files human-readable (and editable), but also contains an explanation of the DCP and what happens to your raw data when it is interpreted using a DCP:

http://dcptool.sourcef​orge.net/Introduction.​html

kirk