Anyone who’s ever tried afocal photography will know why it is not ideal to hold a smartphone to the eyepiece of a telescope. Attending the image settings requires more than two (steady) hands, with the result a wobbly, flickering image of your target – most likely the Moon.
Like its pricier stablemate the NexYZ, the basic NexGO Universal smartphone adaptor connects a smartphone to a telescope, spotting scope, binocular, monocular or microscope to capture images and video through the eyepiece. It’s designed to keep a smartphone positioned in exactly the right position for totally handsfree control. Celestron also sells the NexGO DX smartphone adaptor kit, which comes with a Bluetooth remote.
However, the NexGO isn’t physically smaller than the NexYZ – it’s 12.8oz (362.87g) to the latter’s 10 oz (283 g). That’s despite it featuring just two directional knobs (X and Y axis) to align a smartphone’s camera with the eyepiece.
The NexYZ has a third Z axis – to tweak the distance of the lens from the eyepiece – as well as a safety lock on the smartphone clamp to keep everything safe. Although it works with all big smartphones, in the NexGO’s box is a small booster (read: a small piece of plastic) that boosts smaller smartphones into position.
Thankfully the metal frame and polymer-made NexGO doesn’t droop during set-up. While that’s crucial, the NexGO lacks versatility. While including a Z axis on the NexYZ means you don’t have to precisely position the bracket’s clamp around the eyepiece holder, the NexGO needs far more precision. It’s also only able to clamp around 1.25” eyepiece barrels; it fits any eyepiece from 25.4 millimeter to 44.45 millimeter in diameter.
However, the NexGO has less success when the 1.25” eyepiece on your telescope has a lot of eye relief and a larger, wider barrel, which I found with the Celestron spotting scope I tried it with. The rim of the eyepiece was simply too thick for the NexGO’s hexagonal clamp to fix around. I was eventually able to use it, but only after manually removing both the scope’s eyepiece and the fixing buffer within the NexGO’s hexagonal clamp.
The NexGO includes a Bluetooth remote in the box, but since all smartphone cameras feature shutter-delay options and voice control, I’m not convinced it’s required.
The NexGO seems to work with some products — but not all. However, with a reasonably low price, lightweight build and easy to use setup, Celstron’s NexGO is worth considering for occasional use and astro-travel.
Plus: Includes Bluetooth remote; simple placement using X and Y axis; spring-loaded clamp; easy to insert and remove a smartphone
Minus: Lacks Z axis for extra precision; no safety lock; limited to eyepieces 1”/25.4mm to 1.75”/44.45mm.
Summary: Ideal for afocal smartphone astrophotography on the go, the Celestron NexGO clamp is easy to use and doesn’t slip while in use. However, it works best with eyepieces with narrow barrels and little eye relief.