Western crews entering as tourist / business travellers can visit visa-free for stays of up to 90 days.
Although some crews choose to enter as tourists, to be safe, work visas are recommended, especially if you will be working on a larger film shoot, or filming in national parks, or staying over the 90 day period.
Work visas are applied for at your local Argentine consulate with an invitation letter from an Argentine Production Company that is registered with the ReNURE. The original letter needs to be sent with all the required stamps granted by local notaries. Once the letter is received it can take up to a month to process.