A variety of simple graphical filters are available to camera phone users to enhance their photos on the fly; these filters often stylize, saturate or age a photo. In this paper, we present a combination of large-scale data analysis and small scale in-depth interviews to understand filter-work. We look at producers’ practices of photo filtering and gain insights in the roles filters play in engaging photo consumers’ by driving their social interactions. We first interviewed 15 Flickr mobile app users (photo producers) to understand their use and perception of filters. Next, we analyzed how filters affect a photo’s engagement (consumers’ perspective) using a corpus of 7.6 million Flickr photos. We find two groups of serious and casual photographers among filter users. The serious see filters as correction tools and prefer milder effects. Casual photographers, by contrast, use filters to significantly transform their photos with bolder effects. We also find that filtered photos are 21% more likely to be viewed and 45% more likely to be commented on by consumers of photographs. Specifically, filters that increase warmth, exposure and contrast boost engagement the most.