Hi Haynesb, great find! I've just uploaded a cropped version of your photo so it will be a bit easier for our reptile moderators to see. Cheers, Margot (Southern Highlands Nature Map Admin).
It's a Heath Goanna (Varanus rosenbergi), which is an even greater find, as it's not only a rare and vulnerable species in NSW but it's our first recorded sighting on SHNM.
A good way to tell these two species apart, is by looking at the tail bands. Lacies have fewer and broader, pale tail bands, whereas Heathies have relatively evenly spaced, narrower, pale bands along the entire length of the tail. A different behavioural response to potential predators can also be observed, as Lacies invariably go up a nearby tree, whereas Heathies tend to stay on the ground or disappear down a burrow.