The Earth is constantly in motion, rotating once every 24 hours and taking a lap around the sun once a year. If you want to take great pictures of the night sky, it isn’t enough to know just what you want to shoot, but when. An astronomy simulation app can make planning your next successful imaging session much simpler. SkySafari 5 Pro is one such astronomy simulation app. Can it get the job done?
Versions
Before we get started, I’ll say right off the bat that SkySafari 5 comes in three different flavors, available for both Android and iOS.
- SkySafari 5
- SkySafari 5 Plus
- SkySafari 5 Pro
This review was done on a Samsung Galaxy Note 8 with the top-of-line “Pro” version, although most of the camera-and-telescope-friendly features come in the Plus version as well. The base version comes only with the planetarium display.
Photographer’s Checklist
Earlier, I mentioned a couple of things you’ll want to be able to plan your imaging sessions around, but for simplicity’s sake, I’ll list them here.
Object Visibility
Depending on where you live and what time of year it is, you may not be able to see the desired target on a particular night. The moon phase further complicates things if you’re shooting the Milky Way or deep sky objects like nebulae or galaxies, so it would be nice to know if the moon is going to cause us problems.
Apparent Size
How large does a particular object in the sky appear, and more importantly, how will it appear in your camera’s view finder? Knowing ahead of time can make the difference between imaging as soon as your camera is set up or re-shooting over and over to get things lined up just right.
I’m happy to say that SkySafari 5 Pro can do these things with ease, and much more.
Planetarium Display
With respect to a night-sky object’s visibility, SkySafari lays everything out in a planetarium-like display, showing the entire night sky in all directions above the horizon. Pinch-zoom is supported and scrolling around the sky is as simple as dragging a finger around.
Figure 1: SkySafari’s Planetarium view with horizon coordinates, in both standard (left) and night-friendly (right) modes.
SkySafari is also location-aware. For certain phenomena, like Solar and Lunar Eclipses, how things look depends on where you are on the Earth. SkySafari will automatically use your phone’s GPS coordinates by default, but you can also manually enter coordinates which is super-handy when you’re planning on travelling to a dark-sky site far from home.
Compass
Perhaps one of the coolest features of SkySafari is its compass. When enabled, the Compass feature will use your phone’s GPS and Gyros to determine the phone’s orientation with respect to the sky in real-time. If you are learning constellations for the first time, this feature is fantastic, albeit with a couple of caveats. While the compass worked well for me on my Samsung GN8, it wasn’t near as accurate on my GS5, and didn’t work at all on my Galaxy Tab A. This is almost certainly a hardware limitation, as the GS5 is fairly old, and the Galaxy Tab A is pretty bare-bones and probably lacks the required hardware.
It’s like Google Earth, but for space.
Tapping any object in the display brings up magnitude information and the ability to view its entry in the catalog of objects. It’s really quite impressive the level of detail you can view, from schedules of visibility times for Jupiter’s Great Red Spot to named craters on the surface of the moon. This level of detail won’t matter if you only plan to shoot wide views of the milky way from a tripod, but is invaluable if you image through a telescope.
Figure 2: A close-up of Jupiter (left), showing the shadow-transit of Io and GRS, and Aristarchus crater on the Moon (right).
Several star catalogs are also available, depending on which version of SkySafari you purchased. The Pro version comes with information on 25 million stars, 740,000 galaxies down to the 18th magnitude, 630,000 solar system objects, and satellites including the ISS.
Time Control and Playback
Perhaps SkySafari’s second-most valuable feature is its time control system. By default, SkySafari’s planetarium view updates in real-time, but you can set the simulation to any date in the past or future. Time steps can be measured in a number of different units, including seconds, minutes, hours, days, months, and years, to name a few. Real-time playback can also be set to a specific factor (e.g. 5X real-time). You can also pause the simulation and have it step forward or backward at-will. This powerful feature is what enables a photographer to know where specific objects will be in the sky at specific times and plan accordingly.
Field-of-View Overlay
If the previously-listed features were all you had, SkySafari would be more than enough to plan a shot, albeit with a little guess-work. You’d have to calculate your camera’s Field-of-View (FOV) on your own and then eyeball it against SkySafari’s horizon coordinate grid. But you don’t have to, which brings us to what I think is SkySafari’s greatest feature; the FOV Overlay.
SkySafari has an equipment configuration page where you can enter the aperture and focal length of your scopes (or camera lenses, for that matter), as well as the dimensions of your camera sensors and eyepieces.
Figure 3: Configuration of telescopes/lenses and camera sensor dimensions.
Once you’ve entered the specs for your scopes/lenses and cameras, you can combine any pairing to display their respective field of view. After you’ve chosen a camera/scope combo, you can rotate the viewing angle to see how that combo will frame the desired target.
For instance, I shot the Orion Nebula on December 29th, 2016 using my Canon EOS 70D and Explore Scientific ED127CF scope. Here’s what SkySafari showed would be the apparent field of view, followed by the resulting image from the scope.
Figure 4: Predicted field of view for the Orion Nebula (blue box).
Figure 5: Final image after processing (click to view in gallery). HDR Composite of multiple stacks (30x60s, 30x120s, and 30x240s for a total integration time of 3.5 hours).
Final Thoughts
SkySafari 5 is an excellent, highly-polished app; this review barely scratches the surface of what it is capable of. It handles the two primary concerns (Visibility, Apparent Size) of most budding astrophotographers flawlessly. Overkill? Perhaps, but you can easily plan your next imaging session with it and plenty of additional features to grow into. While some might find the $19.99 asking price a bit steep for a phone app, it is well worth the money. In the couple of years I’ve been using it, it has never crashed once, and I highly recommend it.
One feature not reviewed here is the ability to remotely control a telescope via hardware accessories. Is this something you’d be interested in hearing about? Let me know in the comments below!