Assisting new bino-chair users, e.g., at a star party

The April Starfest at the university, before and after it got dark:

Assisting new users:

Before the new user sits in the bino-chair:

• Have the chair-front counterweight solidly in place (important).
• Demonstrate, or those standing in line could watch the person ahead of them.
• Coarse adjust the teeter mount height and the neck cushion height.
• Coarse adjust the distance out to the oculars, using the thumbscrews, taking into account eyeglasses. However, most don’t need to use their glasses (see the note at the very end below).
• The thick neck cushion should perform best if it is placed low, at the nape of the neck (also see note below for tall users).
• Coarse adjust the inter-pupil distance (IPD) only if theirs is very unusual (less important).
• Push the teeter up out of the way.

Then the new user gets into the bino-chair and …

• They sit fully back in the chair, sitting tall, not slouching (important), unless they are very tall.
• They use their torso strength to tilt the backrest back a little.
• They use their right hand on the cradle (not on the binoculars) to push the teeter/cradle up or down.
• They bring the teeter down in front of their eyes (you could then re-adjust the gap to the oculars using the thumbscrews).
• They can pan using the left hand drive wheel.
• They push the teeter down a bit and look over top of the binoculars for a small star or target.
• They center the small object in the binoculars (from behind, you could nudge the chair and the teeter a little to help line them up).
• Again, they can adjust IPD if theirs is very unusual (less important).
• They adjust the focus, typically one eye and one ocular at a time, while keeping the small target centered.
• They can push the teeter down a bit, and look over top of the binoculars for their next target. Or they can slew to targets while looking through the binoculars. They should ideally do the slewing without touching the binoculars.
• They can make small changes to the eye-to-ocular distance (less important) by swiveling the cradle and then compensating by swiveling the teeter in the opposite direction.   
• For high elevation targets, they use torso strength to push the backrest further back. When new users make large changes in viewing elevation, it is safer without the binoculars directly in front of their eyes. You can adjust the teeter height on backrest again (for example if the binoculars become too close to their eyes when their head is tilted back, then raise the teeter mounts on the backrest). The thick cushion is best if under the nape of the neck.
• For moderate changes to the viewing elevation, they can adjust the tilt of the teeter and/or the cradle simultaneously with one hand.
• To return the backrest by tilting it forward, they can use lower leg strength, and pull on the armrests with one or both hands. To make it easier to tilt the backrest forward, they could first swivel the teeter up out of the way, then lean their head and chest forward in order to shift their center-of-mass forward.

Other advice:

• Those who have more difficulty operating an ordinary zero gravity chair, will need more assistance; this may include very short persons or children.
• Very tall persons may want to slouch a little in the chair. They may want to use a pad on the top rail of the chair’s backrest, as well as a thicker cushion for the nape of the neck.
• For high elevation viewing the teeter mount height setting is important, especially for very tall users. The oculars may start to push against the eye sockets if the teeter mounts are not high enough.
• The chair-front counterweight reduces the chance that the entire chair could tip backwards, and it assists when returning the backrest upright (important).
• Many can choose not to use eyeglasses and can instead focus each ocular. This may not work for those with a lot of astigmatism. For star-hopping when sitting in the chair and not looking through the binoculars, some may need to momentarily put glasses on to see the star locations and to line up.