To visit New Zealand and work you probably need a work visa
Everyone working in New Zealand for any period must be a New Zealand or Australian citizen, and Australian permanent resident, hold a New Zealand residency permit, or a valid work visa (Australians have the automatic right to work in New Zealand). This is the law, and the responsible government department, Immigration New Zealand, is required to implement it.
Visiting producers, directors, cast and crew must apply for a Temporary Work Visa before they come and work. Usually the production arranges the work visas on behalf of the crew. These requirements apply equally to ordinary employees, independent contractors and freelance crew. In Immigration New Zealand documentation the word employee also applies to contractors and freelance crew.
Section W3.1 of Immigration Instructions - Temporary Entry 2 requires, among other things, that the producers show that the crew they want to bring in are manifestly essential to the production, or that they do not put at risk engagement of New Zealand professionals, or that the producer has appropriately looked at engaging New Zealand professionals.
To get a work visa, crew probably need a letter from the Techos' Guild
Section W3.10 of Immigration Instructions - Temporary Entry 2requires, with some exceptions, that the producer obtains the agreement of the relevant New Zealand performers union or professional association. For crew, excluding producers and directors, this professional association is the Techos' Guild. For Producers refer SPADA and for directors or editors refer DEGNZ.
The way to obtain agreement is by requesting from the Screen Industry Guild a letter of non-objection (LONO) which can be forwarded with the visa application to Immigration New Zealand. The Screen Industry Guild normally processes a request for a letter of non-objection within two working days. This will greatly facilitate and speed up most crew visa applications with Immigration New Zealand. The cost of a letter of non-objection is $45 inc GST.