Samsung NX 500 & Samyang 8mm F2.8 UMC Fisheye II, interval 5 seconds, speed 150x
20250309_1530-1630utc_Bohdanec_x264_1920x1080.mp4 (56 MB)
Pre-spring silhouettes and reflections. Bohdaneč Pond, Lázně Bohdaneč (district of Pardubice, Czech Republic).
See also a static photo from the beginning of the timelapse and MTG-I1 (Meteosat Third Generation), Meteosat-12 satellite loops RGB VIS-IR, and RGB Cloud Type (CHMI version) image products. The area was somewhat covered by dust, as can be seen in the ALC profile from nearby Ústí nad Orlicí. The two black vertical lines indicate time span of the timelapse.
Sony A7C & 7Artisans 10mm F2.8 II Fisheye ED, interval 12 seconds, speed 120x
20250321_1830-1926utc_Sulice_normal-mode_x264_1620x1080.mp4 (65 MB)
20250321_1830-1926utc_Sulice_startrails-mode_x264_1620x1080.mp4 (65 MB)
Satellite tracks through the night sky. While some thirty years ago, when I was active in astrophotography, satellite passes through the night sky were rather a rarity that all of us got excited about, today satellites pose a serious problem for wide-angle astrophotography, especially when timelapsing the night sky. Satellites can be removed from a static photo by various methods, but for timelapses this would already be a challenging problem. Fortunately, the Earth itself helps here (to a certain degree) - when satellites enter its shadow, they are no longer visible.
This can be clearly seen in the timelapse above: the satellites flying from the right side of the frame (west) do not reach the left side, southeast part of the image. The same is true for satellites flying in polar orbits (from south to north or vice versa), they only appear or disappear at some distance from the left edge of the frame. Moreover, it is possible to notice how this whole “satellite darkness area” slowly drifts westwards (to the right, towards the center of the frame). This is nothing else than the Earth's shadow - when the satellite enters it, it ceases to be visible (and vice versa). The only trails that make it all the way to the left edge are planes - they usually also have dotted tracks (a result of blinking of their position lights). All of this is nicely visible on both the classic (“normal”) timelapse and the “startrails” version (from about a third of the timelapse onward). See also this static image of startrails, in which the satellite (and aircraft) tracks are shown at their full length. The short gaps in the satellite trails are gaps between the timelapse frames. Another thing to notice is that the satellites do not disappear at any precise location - this is due to the fact that they fly at different altitudes, and the position of the Earth's shadow depends on its height above the surface. Satellites on the lowest orbits disappear most quickly after the sunset, while the higher ones disappear later (if at all).
The last thing that makes this timelapse interesting is the blue color of some of the satellites. In the entire timelapse (just under one hour) I found about seven of them in the images. These might be the newer generation Starlinks, coated with a special coating to reduce their reflectivity (see e.g. info here). Though, I don't know for sure.
This can be clearly seen in the timelapse above: the satellites flying from the right side of the frame (west) do not reach the left side, southeast part of the image. The same is true for satellites flying in polar orbits (from south to north or vice versa), they only appear or disappear at some distance from the left edge of the frame. Moreover, it is possible to notice how this whole “satellite darkness area” slowly drifts westwards (to the right, towards the center of the frame). This is nothing else than the Earth's shadow - when the satellite enters it, it ceases to be visible (and vice versa). The only trails that make it all the way to the left edge are planes - they usually also have dotted tracks (a result of blinking of their position lights). All of this is nicely visible on both the classic (“normal”) timelapse and the “startrails” version (from about a third of the timelapse onward). See also this static image of startrails, in which the satellite (and aircraft) tracks are shown at their full length. The short gaps in the satellite trails are gaps between the timelapse frames. Another thing to notice is that the satellites do not disappear at any precise location - this is due to the fact that they fly at different altitudes, and the position of the Earth's shadow depends on its height above the surface. Satellites on the lowest orbits disappear most quickly after the sunset, while the higher ones disappear later (if at all).
The last thing that makes this timelapse interesting is the blue color of some of the satellites. In the entire timelapse (just under one hour) I found about seven of them in the images. These might be the newer generation Starlinks, coated with a special coating to reduce their reflectivity (see e.g. info here). Though, I don't know for sure.
Samsung NX 500 & Samyang 8mm F2.8 UMC Fisheye II, interval 8 seconds, speed 240x
20250322_1110-1420utc_Kacerov_x264_1920x1080.mp4 (103 MB)
Cirrus clouds above Prague, on their way to Central Europe. See also a still photo from 11:35 UTC, time of NOAA-20 overpass above the area, from which are the following image products: True Color RGB (VIIRS bands 5,4,3), 24h Microphysics RGB, Cloud Phase RGB, Cloud Type RGB, and the 1.38 μm band M9 image.
Motion of the cirrus band as captured by Meteosat-12 (MTG-I1, Meteosat Third Generation - Imager 1): True Color RGB, Cloud Phase RGB and Cloud Type RGB (CHMI version). Red dot indicates place and time of the timelapse.
For interpretation of these VIIRS and MTG RGB image products and bands see e.g. the EuMeTrain Quick Guides.
Samsung NX 500 & Samyang 8mm F2.8 UMC Fisheye II, interval 4 seconds, speed 120x
20250601_1735-1815utc_x264_1920x1080.mp4 (48 MB)
Weak shelf cloud on dissipating thunderstorms and showers (see this radar image) above southern parts of Prague, Czech Republic. Static image from 17:50UTC here.
Samsung NX 500 & Samyang 8mm F2.8 UMC Fisheye II, interval 30 seconds, speed 900x
20250611-13_Klementinum_1728x1080_x264.mp4 (204 MB)
Prague - Klementinum weather station celebrates 250 years of continuous air temperature measurements this year, though the first measurements (with gaps) started already somewhat earlier, in 1772. Other variables began to be measured continuously later on, or have gaps in their series. Klementinum (Clementinum), famous for its Astronomical Tower and Baroque Library, is thus the oldest continuously measuring weather station in the Czech Republic and one of the oldest in Europe. The current station has two locations in Klementinum - the historic one in a first-floor window on the north side of the south wing of the complex (location of the station in photo is marked here), the other one on a platform on the roof of the east wing. More information on the history of the meteorological measurements at Klementinum can be found e.g. here (CHMI) or here.
The timelapse captures illumination of the station in a window during the day, shortly before the summer solstice, when the sun is at its highest and also at its northernmost point on its journey across the sky. Thus, twice a day in spring and summer (after sunrise and before sunset) the sun shines directly on the station, partially shaded by the astronomical tower in the afternoon. The bright source of light traveling in the night low in the southwestern sky is full moon. Westward view from the roof platform.
Samsung NX 500 & Samyang 8mm F2.8 UMC Fisheye II, interval 5 seconds, speed 150x
20250615_1551-1710utc_Okrouhlik_x264_1700x1080.mp4 (71 MB)
Turbulent sky. Weak dissipating outflow boundary (?) south of Prague. See also still image from 16:31 UTC, the radar image from 15:55 UTC with an arrow indicating the boundary, radar loop from 13:30 - 18:00 UTC (with indication of place and time of the timelapse, and its sector), and MTG satellite loop of IR10.5 sandwich product (rather uninteresting for these storms).