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Total Solar Eclipse of 12 August 2026 Spain, Villahoz, Ermita de la Virgen de Madrigal, +42°05'30.5" N, 3°54'16.3" W, 848 m a.s.l. Local circumstances: C1 17.33.49 UT, C2 18.28.52 UT, max 18.29.45 UT, C3 18.30.37 UT, Sunset 19:21 UT (effective 19.15 UT), C4 19.22.12 UT, duration 1 min 45 s by Lorenzo Comolli |
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 Click for high-res Mouse over to view star magnitudes (numbers with 2 decimal digits without the point) or click here for high-res with magnitudes |
| The HDR corona
from the TEC140+ASI6200MM setup. A great amount of fine
detail is visible all along the corona. Prominences from
C2 and C3 contacts were added in red. The
Moon's edge appears oval due to the 1.5 min duration of
this eclipse, as the Moon moved during acquisition. Many
tens of stars are visible, with the brightest being SAO
98574, mag. 6.8, at 42' from the Sun's center. Lunar
craters craters and maria are also visible
thanks to Earthshine. This is the main setup of my eclipse expedition and it was not easy to pack the scope, mount and all accessories in my car, together with my family (2 adults + 2 kids) and everything needed for the holiday. The camera is an ASI6200MM, a full frame of 61 Mpix 16 bit monochrome, and it was my second time using an astronomical camera instead of a reflex camera on a total eclipse (the first being in USA 2024). This was possible thanks to the big improvement in download speeds of modern astronomical cameras, e.g. this big frame sensor downloads to the PC in less than half a second! TEC140 apochromatic refractor plus APM-Riccardi 0.75x reducer (dia 140 mm, FL 740 mm, f/5.3), ASI 6200 MM camera (CMOS full frame 62 Mpix, 16 bit monochromatic, binning 1, 3.76 um/pixel, cooling at +10°C), Scorpio-Astro SA-17 mount, Luminance filter, exposures between 2 ms and 480 ms at 1.32 EV stops at gain 0 (equivalent to 215 ISO, EV stops from 12.7 to 4.7), 171 frames stacked from an effective exposure of 24.4 s captured during 82 s of total duration. Image capture via an automated sequence in SharpCap recording data at ~2 fps with a data flux of 242 MB/s into a SER file. Image processing by Lorenzo Comolli using Siril for preprocessing with dark, flat and darkflat calibration frames, alignment on SAO 98574 (barely visible on the 2 ms exposures group), HDR composition using a custom-made MATLAB script designed to extract the proper part of corona from each exposure group, processing in Photoshop using High Pass and Radial Blur filters as explained in my 2018 tutorial (see end of this page). |
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| Crop of the above image to a smaller field of 1.5x0.8° (aspect ratio 16:9) |
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| Equirectangular projection of the image above, showing radial structures from a different perspective. |
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| GIF animation of the 13 groups of exposures captured over 82 s of totality. Exposures from 2 ms to 480 ms at 1.32 EV steps in 13 groups from 171 exposures. |
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| GIF animation of the only 2 groups, the first and last of totality, with 2 ms exposure (EV=12.7), sum of 7 exp each. The motion of the Moon is clearly visible, and even the small motion of some inner corona detail. |
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| Sequence of
the full eclipse from C1 to sunset captured in a single
composite frame at 3-minute intervals. This is a classic
goal for eclipse astrophotography, which at the time of
film photography was captured on a single piece of film,
and now with digital imaging is compiled from many
frames added together via software with the strict
requirement that camera pointing remains fixed. Sequence obtained with a modified Canon 6D (Baader), Canon 50 mm f/1.8 lens used at f/5.6, exposure 1/13 s during the C1-C2 partial phase and 0.6 s or 5 s during the C3-C4 (with solar filter D=6) and HDR of 1/13-0.6-5 s during totality (without filter), ISO 100, 3 min intervals. Because the framing of totality was not perfectly centered in the frame, I slightly expanded the field on the left using a reference image taken outside of the eclipse, so that the image preserves the actual landscape. |
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| Sequence of C2 and C3 contacts at 5.6 fps
from the TEC140 setup. 25 images per side show a total
duration of 4.5 s per side. In the center is a 2x
magnification of the prominences and chromosphere. The
rapid change in solar appearance is clearly visible,
especially in the high-resolution version. TEC140 refractor reduced 0.75x (740 mm f/5.3), ASI6200MM, SA-17 mount, 0.39 ms exposure at gain 0 (equivalent to 215 ISO, EV=15.0), image capture at 5.6 fps (ROI of 4096x2304). |
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| Lorenzo
Comolli (me) and my friend Emmanuele Sordini in a group
photo taken during totality. This was a key objective of
our expedition, a keepsake to look back on as a reminder
of the expedition. Taken near mid-totality, with the
eclipsed Sun behind, with Venus visible at top-left. It
shows my setup on the left (TEC140), the authors in the
middle (Lorenzo and Emmanuele), Emmanuele's setup on the
right (Pentax 75) and on the far right, our friends
Giuseppe, Valeria, Barbara, Luisa. HDR composition obtained at mid-totality with a Canon 6D, Samyang 14 mm f/5.6, exposure 0.2-0.8-3.2 s, ISO 800. |
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| An all-sky
shot captures the entire sky in a single frame—a crucial
feature when time is limited, as it is during totality! HDR composition obtained near mid-totality with a modified Canon 5D (Baader), Peleng 8 mm f/5.6, exposure 0.4-1.6-6 s, ISO 800. |
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| Rectangular projection
of the above all-sky image. The orange horizon is mainly
on the left and right of the totality. My setup (TEC140)
is at the left and Emmanuele's setup (Pentax 75) at the
right, while Emmanuele and I are posing for the group
photo with the 14 mm lens. |
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| Partial
Eclipse at 18.10.31 UT, 66% magnitude (i.e. fraction of
the solar diameter covered), 15 ms exposure. TEC140 apochromatic refractor plus APM-Riccardi 0.75x reducer (dia 140 mm, FL 740 mm, f/5.3), ASI 6200 MM camera (CMOS full frame 62 Mpix, 16 bit monochromatic, binning 1, 3.76 um/pixel, cooling at +10°C), Scorpio-Astro SA-17 mount, Baader OIII filter (8.5 nm bandwidth), composition of 52 frames over total duration of 10 s. Image capture via SharpCap4.1, processing via AutoStakkert4 and Registax6. Colorized orange. |
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| Partial Eclipse at 18.20.52 UT, 85% magnitude, 16 ms exposure. Other tech data as above. |
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| Partial Eclipse at 18.27.51 UT, 1 min before totality, 98.2% magnitude, 16 ms exposure. Other tech data as above. |
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A solar
eclipse greatly influences Earth's atmosphere. The
temperature, relative humidity, and luminance data show
typical trends, unique to each eclipse and location.
For this event, I used a T/RH datalogger with the sensors positioned 1 meter above the ground on a small tree, with sensors shaded from direct sunlight. During this eclipse, I recorded a temperature drop of only 2°C compared to the baseline trend, versus 5°C in Arkansas (2024), 9°C in Wyoming (2017), 4°C in Egypt (2006), and 7°C in Hungary (1999). Clearly the eclipse near the horizon greatly reduced the temperature drop. A digital luxmeter measured the horizontal luminance: this is a really interesting measurement, which shows the tremendous fall in light, dropping between full Sun at 30000 lux at C1 and totality at only 1.7 lux (to be compared to 1.8 lux in Arkansas 2024, 3.4 lux in Wyoming 2017, 4.1 lux in Egypt 2006). This is the lowest value among my historical measurements, clearly due to the low altitude Sun, although I expected an even lower value due to the Sun's low altitude; this is nearly similar to Arkansas 2024 with the eclipse very high in the sky. Maybe the shorter duration of the totality (only 1 min 45 s) was the key factor. Further analysis needed! During totality I measured the sky brightness with an SQM-L, obtaining 14.29 mag/arcsec˛, which is equivalent to the twilight sky when the Sun's altitude is -6°, i.e. civil twilight. Want to know how dark the sky gets during totality? Just wait for civil twilight—about 30 minutes after sunset! Here are the plots of:
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 Click for the PDF presentation |
| If
you're interested in processing your HDR corona, I invite
you to follow the tutorial that Lorenzo Comolli prepared
after the 2017 USA eclipse. On January 27, 2018, I was
invited by the VVS association in Belgium to present at
the Astrofotografiedag 2018, an astrophotography
conference. One of the presentations was on how to process
the great American eclipse. Be sure
to check out the other presentation on the dedicated
page. |
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