iPhone Photo App: Sunlight Tracker
Monday, April 19, 2010 at 10:00AM | Glyn Evans "Sunlight Tracker: invaluable for those photographers wanting to capture the sun as it turns night in to day, and day in to night." - GE
Developers Description: Sunlight Tracker lets you track Sun's position and gives you the exact angle and elevation of Sun at any time of day for any location. This information is overlayed on top of a google map so you can zoom all the way in and see the Sun's angle/elevation at a certain spot at 8am!.
Key Features:
- Find out sunrise, sunset, twilight times and day length for any day and location.
- Easily track Sun's position and elevation at any time of day for any location. Use it to find the perfect time for photographing your subjects.
- Using Google map, zoom into a spot and then find the direction of sunlight at that spot for any time of day. For instance, you can find out which direction the sun would hit any landscape or a lake or a waterfall or any outdoor subject for that matter and it helps you plan to visit these locations at the right time for best photographic opportunity.
- Save multiple locations and switch between them easily.
- Does not require internet connection for basic functions, so you can take the app anywhere and use it any time. Internet connection is only required when adding a new location, or when using search or using the maps.
- Works on both iPhone and iPod touch.
App Overview
Rise And Set:
This view displays the sunrise, sunset, along with the twilight begin and twilight end time. It also displays the daylength for the current day. To go to a different date, simply swipe across the screen or touch the date to select a different date.
By default the twilight setting displays the civil twilight for the date selected. You can change this to Nautical twilight or Astronomical twilight from the settings tab.
Note- On certain latitudes closer to the artic and antartic the sun either stays above the horizon or below the horizon the entire day (depending on the month of the year). For these days, there are no rise and set events and they are indicated as "--".
Position:
In position view, you can view the Azimuth and Elevation of the Sun. Azimuth is the angle measured clockwise from the north point. For example, if you point your phone towards the north direction of the compass, the azimuth tells you the degree you need to turn clockwise from north to find the Sun at that time of day.
Elevation as the name implies is just the angle measured from the true horizon. Note when using elevation, understand that true horizon is always at sea level and your local horizon in view may or may not be at the true horizon.
By sliding your finger across the time slider on the bottom, you can view how the azimuth of sun and its elevation changes during the course of the day. You can change the date by touching on the date button.
The aziumth graph displays the perpendicular projection of sun onto the horizon plane and the elevation graph displays the degree of elevation on the y-axis (90 to -90) over the time of day (12am to 12am) on the x-axis. The dotted red lines indicate the Sunrise and Sunset events.
Map View:
The Map View displays the same information in Position tab, but it is overlayed on top of Google map. This view is most useful for outdoor photographers who wish to know which spot and time are best to make use of the best available light.
It is also the view that requires network connection since it pulls maps from the network. The red line indicates the current angle of sun (Azimuth) at current time. You can change the time by sliding your finger across the time slider or jump to a specific date/time using the date button. Adding new locations are really simple and you can switch between different locations with one touch.
With help of several mathematical algorithms the app calculates the position of sun, sunrise, sunset times etc.. This means you don't need to be connected to the network to use this app. Take it to any remote place and still get the information you need.However when using the map, network connection is required to pull the map images. When not in network range, get the same information from Position tab and Rise & Set tab.
Locations, Search and Timezone:
To add new location, you can drag the pin on the map to any location and save that location or press the "Options" button on the map for more options.
From the Options menu you can search for a location by city (requires network) or you can manually enter the geographic co-ordinates. You can also switch between Normal view and Hybrid view. The Hybrid view is selected by default.
The locations tab allows quickly switching between different locations. As you select a location, all tabs switch to that location automatically.
When adding a new location, if "Auto detect timezone" setting is turned on, it connects to network to determine the timezone for the selected latitude and longitude. Timezone auto detected this way will adjust for daylight savings time automatically. For this reason, it is better to add all the locations when you have the network connection. (Network connection is required only when adding the locations but not required afterwards when switching between them). If network connection is unavailable while adding a location, you need to enter the timezone manually for the location. Timezone entered manually do not auto adjust for daylight savings.
Please note that the app uses tinygeocoder service to convert a name to latitude and longitude string and uses Geonames to obtain the timezone information. If either of these services are down then you may not be able to use search or auto detect the timezone.
AppStore Link: Sunlight Tracker - Price £1.19/$1.99
Editors comments: I grabbed this app whilst it was free, and last Friday decided to try the app out for the first time as I wanted to take some photos of the sun setting over a volcanic dust encapsulated UK.
Essentially I wanted to know when the sun was going to set in my home town; now I already knew the direction the sun was going to set, although if had I not known, then this app would have told me.
So firing up the app on Friday told that the sun was going to set at 8:08 PM GMT and that it would be dusk by 8:43 PM GMT, so I headed to my vantage point and arrived at about 7:40 PM GMT and prepared to capture the sunset.
During the time between 8:00 PM and 8:30 PM GMT I was able to shoot a number of photos of the sun setting, and with the use of this app I was able to save myself a lot of wasted time sitting around waiting for the sun to set.
Above: "Volcanic sunset" over the UK, edited with CameraBag Colorcross effect, and then cropped.
So what do I think of Sunlight Tracker?
Well, this isn't the only app of its kind, but it is easy to use, and it does tell you the direction the sun will set or rise along with the sunrise/sunset times.
It is also ideal for those occasions when you find the perfect location and want to know if you can capture a sunrise/sunset and at what time, if at all, or for searching in advance to see if a location is ideal for capturing the sun setting or rising.
Whilst this app does have extra features/information that most people will not need, knowing when and where the sun will set/rise is invaluable for those photographers wanting to capture the sun as it turns night in to day, and day in to night.
It is very difficult to rate this app, as it will be invaluable to some whilst of no interest to others, but for me this app will definitely have a place on my iPhone, although it may only get used occasionally, and as such I give it 3 stars.
Reader Comments (3)
I use this app a lot and really find it useful. Perhaps not on a daily basis, but when you want a sunset shot or what to know exactly how long you can go before it's too dark to do any more shooting, then this is great!
I love this app. 5 stars all the way. I think its simply unfair to rate an app 3 stars just because you think you will need it occasionally. Rate an app for what it does well and how well it does something.
@John. Thanks for the comment, and I'm glad this is a 5 star app for yourself. The reason I have not rated this a 5 star app, is this would imply it is a must have app, and whilst it is an extremely useful app, in my opinion it is not a must have one. In my opinion 3 stars demonstrates its usefulness without implying it's a must have, although as has happened in the past, many may disagree, and this is the place to say it :)