BY LENNIE BENNETTTimes Art CriticPop-up restaurants are all the rage right now. They come, then go in a matter of days. But long before these temporary food stops, there were art festivals, the art-world version of a pop-up because they typically set up camp for a weekend and then disappear.Sunday and Monday bring the first such show of 2012, the 39th annual Art Festival Beth-El. It has been around for 39 years for a reason: It's good. It features about 150 artists from the Tampa Bay region and across the country who work in painting, wood, glass, ceramics, jewelry and photography. They generally don't submit an application for inclusion as with most festivals. Instead, they are invited by a small committee of long-standing volunteers who travel throughout the year looking at new artists to join those who return as repeat participants. Most of them have been on the selection committee for years, have gotten to know the artists and consider the year-long process (which they pay for themselves) a personal labor of love.Beth-El has grown over the years, though it probably can't get much bigger since it's held at Temple Beth-El and most available space, indoors and out, is being used. But it has evolved in smart ways, going beyond the classic model of a fine arts and craft show. On one of the terraces, an outdoor sculpture garden is set up with serious sculptures as well as whimsical garden ornaments for sale. On Monday the Avenue of Shops opens with affordable crafts and gift items for sale; snacks and light lunches are available, and musical entertainment gives the place a festive air. (One of my favorite Christmas gifts of all time, a lovely little evening bag with a vintage look, was purchased there by a friend one year.) Syd Entel Gallery sells limited-edition prints. And talented young artists from Pinellas County public and private schools have space dedicated to a juried show of their work with scholarship funds donated by the festival to winning schools. The big deal, though, is the serious art. It's displayed in the temple building, hung salon-style on the walls and in temporary display areas. Because there isn't room for booths, the artists aren't required to be there, but many come anyway. It seems intimate when compared to the sprawl of outdoor festivals. A nice touch is the presence of docents who can answer questions and help with purchases.Lennie Bennett can be reached at [email protected] or (727) 893-8293.