The unit I have has options 1, 3 and 4. The attenuator would not be useful for priting alternative processes since exposures are long and you want all the radiation you can get. The auto vacuum feature is a real convenience, but not a necessity. The light curtain is highly recommended to avoid eye exposure to UV light, but you could just use UV goggles. And some people will install the unit in an enclosed area that will contain the light, which would make the curtain not necessary.
Originally Posted by reggie