Tag Archives: compass direction

The Ideal Handheld App For Catching the Sun, Moon and Stars

Here at StarCircleAcademy we’ve been consuming and testing quite a number of photography related apps. So far none have risen to the promise that a handheld app could bring to the table.  Rather than illuminate what is missing from each app, here I describe what I want to DO with my handheld App.

In the Evening [5_057775+92]

  1. First, I need an app with accuracy to within 0.2 degrees! Why? Because the moon and sun are only 0.5 degrees in angular diameter. If I want to catch the moon exactly behind the Pigeon Point Lighthouse less accuracy will result in a “miss”.
    Monumental [C_038216]
  2. I want the app to accurately measure and save all the relevant data so I can reuse it and share it.  At minimum it needs to keep track of: From location, to location, altitude at the to location (degrees above horizontal), and any additional constraints like the fractional number of degrees that each measurement can vary. In some locations like the shore of a lake there is more leeway to move. In other spots, like the balcony of a building there is little leeway to move.  An ideal app would allow me to stand in two or more different spots to define that leeway.Rise and Shine [C_037951+77]If I’m solving for the moon, I’d like it to also remember the moon phase I’m interested in (usually full or slender crescent). The ability to take notes including things like height of the landmark is a big plus.
  3. Ideally I can save an image representing what I want with ALL data on the image so that if all I have is a photo, I can reconstruct the parameters in other tools or other ways.
    For example, SpyGlass shows me my GPS coordinates, the elevation, altitude and azimuth (compass direction) – though as you can see it’s calculation on where to find the moon is off by about 15 degrees (30 moon diameters) due to iPhone 4 compass inaccuracy.

    SpyGlass copy

    SpyGlass snap. Note that the plotted location of the moon is off due to iPhone compass hardware.

  4. I’d like to be able to pull up my saved locations and re-execute a search to find the next occurrence. For example, a Pigeon Point Lighthouse vista that I really like only occurs a few times a year. It’s not enough to keep track of the one event I photographed or plan to photograph.
    Project Impact [5_057573-615br]
  5. Bonus points if the data is stored in a server somewhere to make it easy to share. Extra bonus points if there is a way to have the server periodically check possible alignments and send me alerts or emails when such alignments are soon to become possible.
  6. For planning shots with the Milky Way or other prominent sky features (like the Andromeda Galaxy and the Great Orion Nebula), the app needs to accurately plot the course of those objects on an Augmented Reality frame. Images of the Milky Way presented must be realistic.  A poorly illustrated Milky Way won’t help me find the galactic center (which is what I most often want) or compare the alignment I want with the foreground I am trying to capture.
    Inflow [C_072091]
  7. For night related photography, the app must also factor in twilight and moonlight. That is, I want to be able point my device at say the Transamerica building and ask the app when (or if) the Andromeda Galaxy will appear above it when there is little or no moonlight.
  8. Make it easy to use, of course.  Most of the apps that embed maps in them are difficult to use on the tiny real estate of an iPhone – and require data connections as well.

Is it unrealistic to think a handheld app could meet these requirements?  I don’t think so. The biggest problem is overcoming the accuracy limitations in the current devices. The iPhone and iPad, for example have quite inaccurate compass readings except in perfect scenarios… but there are some clever ways (I think) to correct for that inaccuracy.  The tilt angle calculations from the on-board accelerometers and gyroscopes seem to be pretty accurate.

What We’ve Tried

  • Inclinometer. Great for measuring angles above the horizon. Even has a voice mode where it says aloud the measurement. Doesn’t do Now includes augmented reality mode so you don’t have to sight along an edge of the device. On an iPad, it seemed to be accurate to about 0.2 degrees!
  • GoSkyMap. Fun interactive sky map. You can change the date / and time and point it “at space” and it will show you great details about what is there. BUT you have to make sure you set the location correctly. Doesn’t have an Augmented Reality mode so you can’t tell how the mountain in the foreground interacts with the Milky Way, for example, but you can ask it where to find constellations and it will indicate which direction you should look.
  • Sky Map. Like GoSkyMap it’s an interactive planetarium.  I prefer to use it without the “point features”. It’s my Planosphere (Sky chart) in hand. Also includes things like Meteor Showers and radiants, a list of “what’s up tonight” showing rise and set times, moon phase, etc.  No Augmented Reality.
  • PhotoPills. Lots of things rolled into one app. Biggest complaints about this app are saving and reusing Plans, usability quirks, a grossly oversized moon or sun icon in the Augmented Reality modes and an inaccurate Milky Way representation. Oh, and I’d really like it if it would measure for me!  The planner would be great if I could have the Augmented Reality compute the Azimuth and Altitude (aka Elevation) for me, especially since it doesn’t seem to have a way to measure like the Inclinometer tool does. I see, for example where someone saved the “Manhattanhenge” event. It would be great if I could load it and click “find next occurrence”. That feature alone might be worth booking a flight to New York!
  • SpyGlass. Clever app with lots of onscreen information in Augmented Reality mode. We especially like the onscreen measurements which are saved when you grab an image.

Do you know of an app that’s highly accurate and will meet our requirements? Let’s hear about it. If it exists on an Android I’ll buy an android!