Sharpcap Pro – Best $17.20 I’ve Spent Lately

I bought a copy of Sharpcap Pro which has a variety of astrophotography uses including polar alignment. I tried it last night with excellent results. The process is a bit similar to Photopolaralign but it’s fully automated. You take a pair of pictures rotating the mount 90 degrees around the polar axis between them and it tells you how far and in what direction to move the mount to correct your aim. You make the adjustment then keep taking pictures while it watches until you get as close as you care to. The image below is a bit hard to follow but it’s telling me that i’m within a couple of arcminutes of correct which is excellent. Sharpcap is doing the same plate solving that my earlier process was doing but it has its own built in indexes and it solves in milliseconds rather than 10-20 sec. Sharpcap would control many kinds of cameras directly but not my DSLR so I had BackyardEOS continually taking pictures while Sharpcap monitored the folder looking at the latest. Despite my newbie fumbling i was done in 10 minutes after it got dark.

Polar Alignment With Pictures!

PhotoPolarAlign

I found a brilliant polar alignment program. You put the camera on the mount and align as well as you can. Then you take two pictures with the camera swung 90 degrees around the polar axis. The software uses plate solving to analyze the two images and tells you how to adjust the mount. It takes me a few iterations at a minute or so each but the results are great – Getting within say 5-10 arcminutes is pretty good but with this process i can get to <1 arc minute – 1/60 of a degree! Last minute I was shooting 3 minute exposures at 200mm with no star trailing.

A couple of caveats: The script is written in Python 2 which is obsolete and i had to poke at it a bit to get it working; It depends on downloading the cygwin software to run the astrometry software on windows which is also unfamiliar. The best info i found was in a forum post started in 2014.