Using a star tracker is one method for capturing starry landscapes with incredibly detailed skies. As the earth rotates on its axis, stars appear to move across the sky. (Or, for the flat earth crowd, as Apollo’s chariot moves across the sky, the sun and stars are dragged across.) To capture sharp photos of stars, a tracking device is needed.
Available star trackers, however, have a thing or two missing. To make them a great experience additional devices are needed.
Polar alignment is not the easiest thing to do with any tracker, and this is one way the trackers fall down on the job. The Vixen Polaris was one of the first commercial trackers available, but while it does a good job it has limitations. Although it is one of the more expensive trackers, it missed doing a couple of things right the first time—most notably, polar alignment. The original version of the optional polar alignment scope did not have an illuminator. The current, even more expensive polar scope does have an illuminator. For a couple of dollars, however, you can upgrade the old version.
To do the upgrade, I took a 1/2-inch plastic water pipe T and modified it to fit. Using sandpaper, I enlarged one end of the T to fit onto the objective end of the polar scope. On the side part, I attached a zipper pull tag light made by Nite Ize for the light source. I painted the red lens with some red fingernail polish to reduce the light’s brightness. The whole assembly slides onto the polar scope and makes the reticle easier to see
Laser Pointers
I made my own laser pointer for my Vixen Polaris. I got a cheap eBay laser pointer, green, and attached it to a Smallrig Cold shoe with a 15mm rail adapter. Unfortunately, the Smallrig piece is no longer listed on their website. Too bad—because it does help get a good polar alignment. The momentary ‘on’ switch on the laser? I use a simple plastic clamp that resembles a clothes pin. A word of caution about lasers. Even the smallest of lasers can damage your eyes. Never look into a laser beam without wearing proper safety glasses. Never shine the beam at any creature that has eyes. At night, make sure the beam is not pointed towards any vehicles or aircraft.
Polar scope illuminators
On my Skywatcher Star Adventurer mount, the polar scope comes with an illuminator. It is a somewhat clumsy design and I am sure I eventually will lose it or break it. Taking the suggestion of Alyn Wallace, I added some glow-in-the dark tape. You can make this yourself if you have access to a 3-D printer ( https://cults3d.com/:111940)
I did try the Glow in the Dark tape that Allyn suggests. It didn’t work that well for me. But I do have glow in the dark tape all over my rig to cut down on those dark sky oops!
Move Shoot Move sells a laser pointer to add onto the Skywatcher. I already had a laser pointer so I made a quick trip to my local hardware store to purchase some plumbing parts. A few minutes later, with the help of a saw and some sandpaper, I had a laser pointer that fit onto the polar scope.
Should you be averse to lasers and polar scopes, there are other very inexpensive ways to do polar alignment. On YouTube, Nightscape Images has a method using a compass and a piece of wood. Richard Tatti is addicted to his tea and biscuits but also has many good ideas.
Later in the video he mentions a device made in New Zealand to help get polar alignment while using his cell phone. But there is an even easier option should you have the Star Adventurer Dec Bracket. I simply lay my iPhone on it and use the Stellarium app. Polar Scope Align Pro and the Star Adventurer Console apps will also do the same thing.
Intrigued, I tried this. I was in the middle of Joshua Tree National Park, in California.
It wasn’t the best conditions for night photography, cold and the first quarter moon, but I tried.
Well out of cellphone range, my iPhone had no troubles finding my polar alignments.
For those not aware, modern cell phones geo locate by cell phone signals. Turn off the cell phone signals and they rely instead on their internal gps receiver. It is fairly accurate. In my case it allowed me to get good enough bearings to do polar alignment with a degree or so.
