FORKED TONGUES & WIDEMOUTHS Here the subject is 30 inches away and still comfortable enough to remain natural while I sit eye to eye in front of it- It resets its jaws/flicking its tongue to sense the world, especially my presence. Don't try this as most folks may not know the kind of species they are dealing with. Each species has its own safe zone- you should only work outside this zone. Do not recommend even touching subjects-let them remain natural, unless handled by a professional during rescue. Snakes are skittish, but this one was busy looking for prey.
Began filming from a distance, staying low- so no looming shadow to scare it. Gradually move towards the subject. I move @ less than 1/10th inch every second. If your reptile subject has not already been fully alerted then at a motion rate that is slow it may not get alarmed easily. Even when your fingers move around the manual focus ring or to and fro between exposure dials, the motion should be slow & controlled.
You can move faster when the subject is not looking which gives a blind spot window (but animals have so many senses getting a blind spot is not easy) For example this snake kept going into rocks/foliage to look for food, letting me move closer even quicker. Once settled, inch forward towards it without introducing vibrations on the ground.
It finally scurried away only when an assistant about 15 feet behind me, took steps to the side, allowing the snake to sense motion and vibration, even though it was not alarmed by a person just 2 feet away.
We get messages for interning as DOPs. As gifted as an interning DOP maybe, I suggest learning field-craft in natural spaces. This being important for even a regular photographer, even before the camera comes on. Think what if you can take just 36 images from a roll and a tiger steps out giving you a small window of few seconds to take the best shots. Understand wildlife behavior and how they will react within their habitat. Whether you want to join a professional shoot/crew or go for that bucket list wildlife trip, knowing basics of wildlife field craft and how to work your camera around it will help you do better justice to those special moments on filming schedules where time and costs can be very precious. Field craft can be learnt very easily in your own city/town/village you live in or even at your place so that you get comfortable with the camera and any subject.
But all that said- if you are just starting off or enjoy photography-just pick up your camera, even your mobile or point-and-shoot and let it roll, learning photography and field craft along the way! The DSLRs and REDs can come later.