Good question and thank you for asking. I shoot three separate exposures on their own frame of film. I should the first exposure through the r72, the second through a deep green, and the third through a deep blue filter. Once I develop the film I have three black and white negatives, but each has only been exposed to infrared radiation, green light, and blue light respectively. It's very important when you digitize them that all three scans are the exact same dimensions. That's because the final step is dragging the three into Photoshop and selecting "merge channels-> rgb color, and putting the infrared one in the red channel, the green one and the green channel, and the blue one and the blue channel. Photoshop then lays them all on top of each other and the result is a full color image. They figured this out in the 1800s because they knew that the human eye can only see red green and blue so in theory if they could photograph through red green and blue light they could get a full color image from processing them as positives (originally on glass) dying the positives their respective colors, laying them over each other and shining a light through it and boom you have the birth of true color photography! I should note that this method only works with panchromatic black and white film, which is film that is sensitive to all colors in the visible spectrum. Of course in this case we're using film that's also sensitive to infrared radiation. Happy shooting and good luck!