A truly innovative and unique feature of the R Line is the E-Module, which connects (by cable) to the helical focus ring and provides a real time digital readout of the current focus distance. This eliminates the need to translate a desired real-world distance (e.g. 15 feet) into the appropriate numerical value shown on the helical focus ring (e.g. Red 12.4).
Because of it’s digital nature the e-module can also read out depth-of-field information. The closest and furthest point which is still in focus is clearly read out (three sets of points are listed which correspond to three different apertures). Unlike every depth-of-field guide we’ve seen incorporated into any digital camera system this read-out allows you to specify the resolution of the image you are capturing. This is very important since the depth that is in crisp focus (as viewed at 100%) is very different when using an 80mp digital back than it is when using a 22mp digital back. It also allows for micro-adjust (similar to the micro adjust found on a Canon SLR) to account for the minute differences between different lenses, body, and digital backs.
Once you’ve set the resolution (via the micron size of the sensor) and entered in the offset, the depth of field indications are incredibly accurate. This system allows for the most precise and easy to use hyperfocal focusing we’ve seen on any system and allows those, who are so inclined, to do incredibly precise depth of field stacking with very little effort (just turn the focus until the e-module indicates the last image’s far point overlaps with the next image’s near point.
The e-module also features a built-in sonic distance finder which provides you a convenient method of reading subject distance. This is the most commonly referenced feature in press releases and reviews. However, Capture Integration does not believe this is the most compelling feature; it is difficult for a sonic distance finder to target small subjects. It works quite well for architecture (e.g. finding the distance to the front facade of a building) but it is not well suited to determine the distance to a specific small subject in the scene (e.g. a particular rock or a particular tree). For such cases a laser distometer, gun sight, golf sight, or tape measure are better tools for determining the exact distance to a hard-to-read subject.
Unlike the focus distance and depth-of-field guides on comparable products the e-module can be comfortably read from behind the camera allowing the photographer to precisely adjust focus and compose from the same side of the camera.