The internet is awash with shaky smartphone footage, but a group of filmmakers has proved that it's possible to use them to make entire movies fit for the big screen.Uneasy Lies The Mind is the first narrative feature length movie to be shot entirely on the iPhone.One issue the makers had to overcome while filming the 88-minute movie was the fact that phones don't work very well in cold temperatures and the shoot was in America's frigid Mammoth Lakes in California. But it turned out that keeping it under their armpits helped.Director/producer/cinematographer Ricky Fosheim said: 'Extremely cold weather, as low as five degrees fahrenheit, proved to be one of the most difficult hurdles while shooting. A fully charged iPhone 5 will die in less than two minutes when exposed to these frigid cold temperatures.‘In between takes the filmmakers would have to place the camera underneath their armpits in order to keep it warm. Numerous takes were lost because the camera would continuously die mid-shot.’The makers say that while there have been numerous 'found footage' iPhone movies - self-reflexive movies in which the actors hold and talk directly to the iPhone - a couple of documentaries and numerous short films, their movie is the first traditional narrative feature shot entirely on the iPhone.The movie’s plot revolves around Peter, a freshly minted movie star. He has it all: wealth, fame and a beautiful expecting wife.But when the couple’s two best friends join them at their new mountain mansion for Peter’s birthday, envy, secrets and paranoia play out behind a barren winter landscape.Soon the two couples grow increasingly antagonistic and turn to alcohol and drugs to bury thepast. When an old friend shows up unexpectedly, Peter must scramble to protect his new life. Theharder he fights to hold it all together, the faster he descends into a cavernous mental abyss. As the night grows late, Peter is forced to decipher reality from a twisting rabbit hole of truth andillusion.The film, shot on a budget of just $10,000 (£6,000) by Detention Films, is told from the perspective of a man who has been robbed and violently hit over the head. As he lays dying in the middle of an open field, the story unfolds through his fragmented and traumatized memories. These memories are far from crisp and clean, so the visuals in the story needed to reflect this, the makers said.They originally wanted to shoot on 16mm film. Without the budget for it, they decided to go on a quest to replicate a 16mm film aesthetic with modern day camera technology. After playing around with the iPhone 5, and a lens adaptor called the Turtle Back, they fell in love with the look and knew right away that this was the aesthetic in which to tell the story.Fosheim added: 'In the middle of the Turtle Back Lens Adaptor is a glass focusing screen with a patterned texture, almost like a finger print. Hair, dirt, and oil from my hands would always get stuck on these focusing screens. 'I completely welcomed these textured imperfections and chose not to clean or replace any of the dirty parts. At times I would even add dust and dirt.'While shooting I used the Filmic Pro app. It’s incredibly powerful and allows you to control the frame rate, compression, and numerous other settings.'The movie is being shown at the Cinequest Film Festival in San Jose on March 8 and the following day at the SXSW festival in Austin, Texas.(dailymail.co.uk)ANN.Az