iOptron Mounts, Star Trackers and Telescopes

What iOptron makes

iOptron's About page describes the company as one that develops, manufactures and markets astronomical telescopes, mounts and accessories. Its home page leads with mounts. In our Amazon US data the 14 live listings break down like this:

• Star trackers: seven SkyGuider Pro listings in different packages
• GoTo mounts: HEM44 with iPolar and HEM44EC
• Tripod pier: the Tri-Pier for GoTo Mounts
• Telescopes: the Photron 10" Ritchey-Chretien, the Astroboy, and two 70 mm refractors (6002 and 6003)

A mount is the part of a telescope setup that holds the tube or camera and moves it. For photography it's the part that matters most, because it has to follow the sky smoothly for minutes at a time. That's iOptron's main business, and it shows in the list.

iOptron SkyGuider Pro: one tracker, many packages

The SkyGuider Pro is a star tracker, a small equatorial mount for a camera. iOptron's page gives it an 11 lb (5 kg) balanced payload, not counting the counterweight; four listings in our data state the same 11 lb. The page lists an AccuAlign illuminated polar scope with about a 6-degree field, and four tracking rates: 1X for stars, 1/2X for sky and landscape together, solar and lunar.

Here's how the packages differ in our data:

• Head only: the tracker itself, polar scope listed. For someone replacing a head or who already owns the bracket and counterweight.
• Head only with iPolar: the same idea, with iPolar named in the title. iPolar is iOptron's electronic polar alignment option; check the listing for what's included.
• Full package: head plus the parts iOptron's page lists: alt-az base, polar scope, MiniUSB cable, padded bag, DEC bracket with camera disk, 1.35 kg counterweight and shaft.
• With all accessories: tracking rates listed as 1X, 1/2X, solar and lunar.
• With iPolar: two listings, both with the 11 lb payload; one lists celestial, solar and lunar rates.
• Full package with viewing chair: the full kit plus a chair, payload and four rates listed.

That last one made me laugh. It's the first tracker listing I've seen that comes with a place to sit while it does the work. I'm in favor. A tracker exposure is mostly waiting.

iOptron's page says the camera, lens, telescope, ball head and tripod are not included in its package. Plan for a sturdy photo tripod and a ball head.

Which SkyGuider Pro package fits

My one opinion here: for a first tracker, buy a package with the DEC bracket and counterweight, not the head alone. iOptron's page says the bracket is for heavier camera and lens setups. Even if your first lens is light, the second one rarely is, and a head-only listing leaves you shopping for parts with the clear night already started.

The head-only listings are for a second purchase: a replacement, or a spare for a second tripod. For the full how-to on payload, polar alignment and the night's routine, see our star trackers page.

Tracking rates, in plain words

The listings name rates in slightly different ways, so here's the translation. "1X," "celestial" and "sidereal" all mean star speed: the camera turns once a day, opposite to Earth. "1/2X" turns at half that speed. iOptron's page says it's for sky and landscape together, so the stars smear a little and the ground smears a little, and both stay mostly sharp in one frame. "Solar" and "lunar" are the slightly different speeds of the Sun and Moon across the sky. iOptron says all four rates work in both hemispheres.

One listing in our data names only celestial, solar and lunar. Another names all four. If the 1/2X rate matters for your landscape shots, read the rate line on the exact listing before you order.

iOptron HEM44 GoTo mounts

The HEM44EC lists a 44 lb payload. The HEM44 with iPolar is a sibling listing; the data doesn't give its payload. Both are GoTo mounts, meaning motorized mounts that find objects from a database and track them.

A 44 lb payload is room for a real imaging setup: a mid-size refractor or reflector, a camera, a guide scope and a filter wheel. It's four SkyGuider Pros' worth of stated payload. These suit an imager moving up from a tracker or a light mount. Skip them for a first telescope; the mount's job only makes sense once you know what you want to put on it.

Tri-Pier

The Tri-Pier for GoTo Mounts is a three-legged pier that holds a mount head higher and steadier than a camera tripod. It's for a heavier mount and a long tube that needs to clear the legs. If you're on a SkyGuider Pro, you don't need it.

iOptron telescopes

Photron 10" Ritchey-Chretien

The Photron lists 254 mm (10.0 in) of aperture and is sold as an OTA only, meaning the optical tube without a mount. A Ritchey-Chretien is a two-mirror design built for photography across a flat field. A 254 mm tube needs a mount like the HEM44 class or bigger. It isn't a first telescope.

Astroboy

The Astroboy is a 60 mm refractor on a computerized alt-az GoTo mount, with GoTo listed. It's a small scope with motors. A first scope for someone who wants the mount to find things, and a light one to carry. At 60 mm, it gathers less light than the 70 mm refractors below, so think of it as a Moon, planet and bright-cluster scope. The tradeoff is the right one for some families: a smaller tube that finds its own targets gets used more than a bigger one nobody can aim. Check the listing for what powers the mount and how it's aligned.

6002 and 6003 refractors

Both are 70 mm refractors on manual equatorial mounts. The 6002 lists a 900 mm focal length; the 6003's name says 700x70. At f/12.9, the 6002 is a long, slow tube, good for the Moon and planets at moderate power.

By Celestron's eyepiece guide, highest useful magnification is about 60x per inch of aperture. For 70 mm, that's about 165x. A box that promises far more is selling a number. These suit a curious kid or an adult on a small budget willing to learn an equatorial mount. Skip them if the setup instructions will end up in a drawer; an alt-az mount is easier on night one.

Building a night around a SkyGuider Pro

A tracker is the center of a small kit, and most of the kit isn't in the box. Here's what goes in the bag before the first night:

• A sturdy photo tripod. The tracker can't fix a wobbly base.
• A ball head between the tracker and the camera, unless you use the DEC bracket.
• The camera and lens, with a charged spare battery.
• A remote shutter or intervalometer for long exposures.
• A red flashlight, so your eyes stay dark-adapted.
• A charged tracker. iOptron's page lists a built-in rechargeable battery charged over MiniUSB.

Then the routine. Level the tripod. Set the base to your latitude. Polar-align with the polar scope. Mount the camera, balance it with the counterweight if you use the bracket, pick the rate, focus by hand and take a test frame. Zoom in on the test frame and check that the stars are points. If they're short lines, the alignment needs another look, not the tracker.

Tracker or GoTo mount: the iOptron fork in the road

Most people who land on this page are choosing between a SkyGuider Pro and a full mount. The listings make the trade clear.

A SkyGuider Pro carries a camera and lens, 11 lb by its listed payload. It packs into a bag, runs on a battery and has no hand controller. It doesn't find objects for you; you aim the camera yourself.

A HEM44 mount carries a telescope rig, 44 lb on the HEM44EC listing. It finds objects with GoTo and tracks them, but it needs a pier or heavy tripod, power, and more time to set up.

If your photos will be wide: the Milky Way, constellations, a landscape with stars, the tracker is the tool. If your photos will be one galaxy filling the frame, you need focal length, and focal length needs the mount.

Who should skip iOptron's list

Skip the HEM44 mounts and the Photron tube if you haven't used a telescope before. They're second-step gear.

Skip the SkyGuider Pro if you only want to look at the sky. A tracker has no eyepiece. Our stargazing binoculars page is a better start for looking.

Skip the 6002 and 6003 if you want GoTo; both list manual equatorial mounts. The Astroboy is the GoTo option in iOptron's small-scope listings.

How to pick an iOptron

1. Camera and lens on a tripod: SkyGuider Pro, full package or with all accessories.
2. You already own the bracket and counterweight: head only.
3. Telescope, camera and guide scope: HEM44EC or HEM44 with iPolar, plus a pier or heavy tripod.
4. A small scope for looking: Astroboy for GoTo, 6002 or 6003 for a manual mount.

Theo saw the 1/2X rate on the list and asked if it was half credit. "It is half the sky's speed," I told him. He wrote "partial tracking" on the whiteboard for his class the next morning.

Sun safety

Never look at the Sun through a telescope, binoculars, a finder or a camera, or with your eyes, without a certified solar filter made for that purpose and fitted correctly. Eye damage can be instant and permanent.

A solar tracking rate keeps the Sun in the frame. It does nothing to protect your eyes or your camera. The American Astronomical Society says the solar filter goes on the front of the camera lens or telescope.

Read the package line twice. The chair is optional. The counterweight isn't.