Amy Seimetz and Thomas J. Madden in "Be Good"

There’s a dedication at the end of “Be Good,” by which time you’d need no other knowledge than the film itself to know it’s the wife and daughter of writer/director Todd Looby. Although Looby actually plays a supporting role in the film and his daughter is revealed to play the six-month-old daughter of the film’s central couple, such authenticity is made obvious not from their participation, but in the way “Be Good” is able to make the stakes feel so high when chronicling the rather mundane lives of new parents Paul (Thomas J. Madden) and Mary (Amy Seimetz).

Naturally, Paul is a filmmaker, which would seem to make him the obvious choice to stay at home with the couple’s young daughter Pearl as he finishes his latest screenplay, yet Mary can barely escape the house when her maternity leave ends, kissing Pearl’s forehead so much that it appears she hopes one will stick so she can’t leave. The arrangement never really works as well as it should – Paul needs breaks away from Pearl, who is prone to screaming, as Mary often retreats to the basement of her office building to pump breast milk – but each try to adjust as best they can, the enormity of what a child means to them seeping into all other aspects of their lives both together and separately.

A lesser film might resort to a more obvious battle of wills, but Looby trusts his actors to show that their characters are their own worst enemies in glances and small talk. Paul grows bitter as he wonders if he should continue in a career he knows is hardly financially secure, though he also believes he shouldn’t be sacrificing what professional success he has built up while Mary becomes increasingly more weary of the time she spends away, suspicious of the things she has to hear secondhand about her baby after returning home from work, the conflict reflected in a delicate yet upbeat acoustic score from Dan Macaluso that brings a balance to “Be Good.”

Even without the presence of Joe Swanberg in a cheeky cameo as himself, a source of professional jealousy to fellow Chicagoan Paul who winces at the eight movies Swanberg makes while spending time with his kid, the film clearly takes what form it has from mumblecore-era productions with a loose feel to cinematographer Mike Gibisser’s camerawork and an unforced intimacy. However, just as those films developed into something more mature as the filmmakers behind them did, “Be Good” appears to have refined the personal quality that made them special while being more elegant than its other ultra low-budget predecessors.

Having Seimetz at its center will help with that, luminous even as she wears her emotions on her sleeve, and she is countered nicely by Madden’s more determined turn as Paul, convincingly trying to keep his cool as the anxiety of providing financial sustenance for his family and creative sustenance for himself takes its toll. In spite of its clearly autobiographical underpinnings, Looby demonstrates a self-awareness and a light touch that may be necessary to keep “Be Good” from being overwrought that happens to also make for an unusually simple and affecting snapshot of being a new parent. It isn’t just a sweet baby girl settling in here, it’s a promising filmmaker too.

“Be Good” is now available on iTunes, Amazon and GooglePlay.