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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 My other TSE pages: 2024 2019 2017 2009 2006 2005 1999 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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| 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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| 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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| Medium field of view HDR
solar corona. Raw data obtained by my friend Gianni
Galli from the same location as me (~200 m away). The
setup consisted of a Pentax 75 APO refractor (500 mm
f/6.7) and an ASI2400MC color CMOS camera, controlled
via the same SharpCap script I used for my own setup.
Many stars are visible thanks to the large field of
view, while still maintaining high detail in the corona. The center of the image (Moon, prominences, and the innermost corona only) comes from the TEC140 + ASI6200MM setup. Setup: Pentax 75 apochromatic refractor (FL=500 mm, 75 mm aperture, f/6.7), ASI2400MC (full-frame 24 MP color CMOS, 16-bit Bayer matrix, binning 1, 5.94 µm pixel size, cooled to +8 °C), Juwei-14 mount. Exposures: Ranging from 1.5 ms to 512 ms in steps of 1.40 EV at Gain 140 (equivalent to ISO 465, EV range from 12.6 down to 4.2). 382 frames were stacked for a total net exposure time of 60 s, captured over a gross duration of 84 s. Image capture was executed via an automated SharpCap sequence, recording into a SER file at 7.7 fps with a throughput of 362 MB/s. Image processing with Siril, Photoshop and Matlab as described above. Image processing: Lorenzo Comolli. Image setup control: Gianni Galli. This image is a collaboration between Lorenzo Comolli and Gianni Galli. |
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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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| Animation of the C2 and
C3 contacts, crop at 100% original resolution and
rotation parallel to the contact lines. Tech data as
above. |
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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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| Sunset taken
with the TEC140 and ASI6200MM. The eclipsed Sun sets
behind a small hill at a distance of 9.7 km and 0.3° of
altitude (according to PeakFinder data), where other
eclipse observers were stationed (note the cars and
people). The original frames, oriented with celestial
North at the top, were cropped and rotated to level the
horizon in a 16:9 format. False colors were
added (since the sensor is monochrome). The image was captured using the TEC140 and ASI6200MM (refer to the HDR corona description for technical details), without a solar filter but using a G (Green) filter. Exposure was set to 18 ms with gain 0, taken at 19:15:21 UT. |
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| Collage of 9
frames of the eclipsed Sun sunset, taken with the TEC140
and ASI6200MM. Tech data as above, images from 19.14.36 UT to 19.17.20 UT. |
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| Timelapse of totality from the
50 mm lens. The change in ground
illumination is dramatic. Images created from HDR
compositions. Sequence captured with a modified Canon 6D (Baader), Canon 50 mm f/1.8 lens stopped down to f/5.6, AEB ±3 EV, fixed exposures of 1/13 s - 0.6 s - 5 s (EV 8.7 / 5.7 / 2.7), one triplet every 10 s, ISO 100. The totality framing was slightly off-center. Processed with 8x AI frame interpolation to smooth the transition from the original 17 frames to 129 final frames. |
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| Timelapse
of totality from the 14 mm lens. Best
view of the umbral shadow moving from right to left.
In the foreground, my friends and I move quickly to
observe the event and check the instruments. Images
created from HDR compositions. Sequence captured with a Canon 6D, Samyang 14 mm f/2.8 lens stopped down to f/5.6, AEB ±2 EV, AV mode (exposures during totality: 0.2 s - 0.8 s - 3.2 s), one triplet every 5 s, ISO 800. 60 frames total. |
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| Timelapse
of totality from the 8 mm lens.
Ultra-wide view showing the sky illumination
changes. Images created from HDR compositions. Sequence captured with a modified Canon 5D (Baader), Peleng 8 mm f/3.5 fisheye lens stopped down to f/5.6, AEB ±2 EV, AV mode (exposures during totality: 0.4 s - 1.6 s - 6 s), one triplet every 8 s, ISO 800. 39 frames total. |
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| Timelapse
of the sunset taken with the TEC140 and
ASI6200MM. The eclipsed Sun sets behind
a small hill at a distance of 9.7 km and 0.3° of
altitude (according to PeakFinder data), where other
eclipse observers were stationed (note the movement
of cars and people). The original frames, oriented
with celestial North at the top, were cropped and
rotated to level the horizon in a 16:9 format. The
subtle movement of the landscape is a residual
effect resulting from the compensation of the
telescope mount's sidereal tracking. The sequence was captured using the TEC140 and ASI6200MM (refer to the HDR corona description for technical details), without a solar filter but using a G (Green) filter. Exposure was set to 18 ms with gain 0, at 2 fps, spanning from 19:14:36 UT to 19:18:23 UT (with the final frame showing the Sun at 19:17:34 UT). |
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| Slices of the umbral shadow
movement from the 14 mm lens. The
umbra is moving from right (North) to left (South),
with the Sun positioned to the West. Sequence captured with a Canon 6D, Samyang 14 mm f/2.8 lens stopped down to f/5.6, AEB ±2 EV, AV mode (exposures during totality: 0.2 s - 0.8 s - 3.2 s), one triplet every 5 s, ISO 800. |
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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! This eclipse was very low above the horizon (8.2° at my location), so I tried to measure the atmospheric extinction based on the brightness of the solar disk during partial phases. I measured a value of 3.7 EV during totality, which is much higher than what I expected (1.4 EV) considering standard extinction models and the extinction I had measured at my home location the month before with the Sun at the same altitude. The haze that day was probably particularly heavy, though fortunately without any unsightly linear gradients that would have affected the totality imaging. The ability to capture so many stars down to magnitude 12 is therefore even more incredible.. Here are the plots of:
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The key
to imaging the HDR corona with the TEC140 and ASI6200MM
is an automatic sequence carefully prepared in the
months prior. Just like for the Total Solar Eclipse in
the USA in 2024, I used the excellent SharpCap software
with the "Sequence Editor" feature. I prepared an "SCS"
text file with all the commands by editing it with
Notepad++, and I calculated the delays and exposures
using an Excel file that automatically compiles the
central sequence commands based on input parameters such
as C2 and C3 times, as well as the desired number of
exposures. Detailed camera timing parameters were
included so that when I arrived on-site on the day of
the eclipse, I could easily update the C2 and C3 times
and the number of exposures, then copy and paste the
commands tailored to the exact observing location into
the SCS file.
Image sequences were then saved as SER files on my PC's SSD. A modern PC and a fast SSD are required so as not to lose any frames from the 242 MB/s download stream (i.e. ~117 MB/frame at 2.1 fps). |
 Actual exposures measured from the SER file. Each circle represents a single frame. A total of 171 frames was collected in the central sequence. Exposure times are estimated from the brightness of the corona because SER files do not include the exposure time of each frame, but only the timestamp. Therefore, the measured exposure values seem to slowly decrease due to the increasing airmass extinction at an altitude of about 8°. |
 The XLS file used to prepare the sequence. Note also the contact sequences. |
 SharpCap Sequence Editor with the actual script used for imaging. I just needed to press "Run" about 12 min before C2, and the software automatically recorded all the images of the partial phase and totality from C2-10min to C3+10min. An example image of the eclipse is in the background. |
 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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