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Main Screen Layout


Initial Setup

Eclipse Preparation

Script File Format

Camera Configuration



Shortcuts and Tips

Credits & Acknowledgments

Besselian Elements and Lunar Limb Profile

Eclipse circumstances are calculated using the Besselian elements from Fred Espenak’s NASA Solar Eclipse bulletins. A digitized version of Espenak’s lunar limb profile can be used, but the application automatically computes, with greater accuracy, the lunar limb profile at the observer’s location using Watts data (low accuracy) or the ones from the more recent Kaguya and Lunar Reconnaissance Orbiter lunar missions (higher accuracy). Formulas are primarily from Jean Meeus’ books Elements of Solar Eclipses and Astronomical Algorithms.

Memory Cards

Using the fastest memory card your camera can handle is highly recommended: doing so will let you take even more exposures by reducing the delay between each picture. SD (Secure Digital) cards tend to be slightly slower than CF (Compact Flash) cards. When available using a XQD or CFast card is a must.
Recommended cards: Lexar Professional (150MB/s), SanDisk Extreme Pro (160MB/s, 100MB/s, 90MB/s), Extreme (60MB/s) or Extreme IV (45MB/s)

The XDQ memory cards (440MB/s 2933x and 168MB/s 1100x) are the fastest and will only be available with the following cameras:
- Nikon D500, D850, D4, D4s, D5 (XQD)

A SanDisk Extreme Pro or any equivalent memory card (160MB/s 1067x UDMA 7, 100MB/s 667x UDMA 7 or 90MB/s 600x UDMA 6) will only be useful with the following cameras:
- Nikon D300, D300s, D700, D3X, D3s, D800/D800E, D810/D810A, D4, D4s, D5 (CF)
- Canon EOS 50D, 7D, 7D Mark II, 5D Mark II, 5D Mark III, 5Ds/5DsR, 1D Mark IV, 1D X, 1D X MkII, 1D C
A Lexar Professional 1066x or any equivalent memory card (160MB/s 1067x UDMA 7 or 150MB/s 1000x UDMA 7) will only be really useful with the following cameras:
- Nikon D800/D800E, D810/D810A, D4, D4s, D5 (CF)
- Canon EOS 7D, 7D Mark II, 5D Mark III, 5D Mark IV, 5Ds/5DsR, 1D X, 1D X MkII, 1D C
However a Lexar Professional 1066x or any equivalent memory card (160MB/s 1067x UDMA 7 or 150MB/s 1000x UDMA 7) will provide substantial gains with the following cameras:
- Nikon D300, D300s, D700, D3X, D3s
- Canon EOS 50D, 5D Mark II, 1D Mark IV

UHS-I U3 capable SD memory cards should be used with the following cameras:
- Nikon D3200, D3300, D3400, D5100, D5200, D5300, D5500, D5600, D7000, D7100, D7200, D7500, D300s, D500, D600, D610, D750, D800/D800E, D810/D810A
- Canon EOS 100D/Rebel SL1/Kiss X7, 200D/Rebel SL2/Kiss X9, 1200D/Rebel T5/Kiss X70, 1300D/Rebel T6/Kiss X80, 650D/Rebel T4i/Kiss X6i, 700D/Rebel T5i/Kiss X7i, 750D/Rebel T6i/Kiss X8i, 800D/Rebel T7i/Kiss X9i, 760D/Rebel T6s/8000D, 77D/9000D, 70D, 80D, 7D Mark II, 6D, 6D Mark II, 5D Mark III, 5D Mark IV, 5Ds/5DsR
- Panasonic GX8, GH4

UHS-II capable SD memory cards should be used with the following cameras:
- Nikon D500, D850
- Panasonic GH5

Before selecting your memory card I encourage you to browse Camera Memory Speed.

Lexar XQD Card
SanDisk Compact Flash Card
Lexar Compact Flash Card
Lexar SanDisk SD Card

Processor Activity

To reduce the CPU activity and give as much time as possible to the process taking pictures while maximizing the autonomy of your laptop, you can turn off or lower the update frequency of the Sun/Moon diagram and eclipse map animations. When a script is running you can also lower the refresh rate for the countdowns. All this can be done using the contextual menus.

GPS Units and Timing

If you connect a GPS to use it as a timing source, make sure the GPS is reliable enough as a time standard. Run the GPS for a few minutes and then observe the rightmost value on the first line of the main screen (it’s in parentheses, a bit to the right of ClkErr). This is the standard deviation of the GPS timing measurements in seconds. If this number is small (less than 0.1s) your GPS is stable enough. If this number is large, something is wrong with the GPS and it cannot be used. Sometimes a GPS unit will give poor timing results when its display screen is set to a graphically intensive page, so try various GPS display pages to see which gives the most stable timing, leaving it on each page for 1-2 minutes.

Airborne and spaceborne Observations

Aircraft and even more spacecraft move quite fast and allow you to extend the duration of totality by following the displacement of the Moon’s umbra. When using a GPS, Solar Eclipse Maestro can follow in realtime the position of the observer and constantly recompute the current circumstances. However, if you don’t use a GPS to constantly retrieve the current position, then each eclipse event can be manually overridden in the Event Times Override dialog or entered at the beginning of the script file.

Lunar Limb Profile

The lunar limb profile generation using the data from the Japanese Kaguya probe was done with my own tool: JAXA Kaguya Selene. The dataset was later improved by using the data from NASA’s Lunar Reconnaissance Orbiter.
To predict accurately the instants of contact and the Baily’s beads shape, one needs to know the actual profile of the Moon (mountains, craters and valleys) as seen for the observer’s location. Until 2009 this was done using Watts charts. In 2009, JAXA’s Kaguya data revolutionized the accuracy of eclipse contact time calculations and NASA’s Lunar Reconnaissance Orbiter LOLA altimeter promises to literally fill in the gaps left by Kaguya. In March 2010, using LRO’s 430 million data points, the profile generated by the Kaguya dataset was further improved and will be updated regularly as new data is coming in.
JAXA Kaguya Selene
Lunar Limb Profile View
Lunar limb profile view

License for diagrams and PDF or Google Earth files

All diagrams and PDF or Google Earth files created with Lunar Eclipse Maestro are licensed under a Creative Commons Attribution-Non Commercial-No Derivs 3.0 Unported License that can be viewed at
Creative Commons License Logo


Solar Eclipse Maestro may need to pull some data from various websites, such as the Solar and Heliospheric Observatory or Google Maps, to display the Sun or interactive maps. During this process no personal information is transmitted.
When checking the existence of a new release from within the application, my server automatically logs information, such as the visitor’s IP address and version of the application to find if an update is available. I do not link server log information to any other data in a way that would enable me to identify individual visitors, except for security purposes, as discussed above.
Personal information is never disclosed to any third party without your prior consent.