Exposure stacking of a moonlit landscape - a challenge in Photoshop

 

You may have tried this yourself, trying to photograph a nice landscape with the moon during the twilight hours in the evening or morning. For a landscape like this you need a tripod and a long exposure time. The moon being many times brighter needs a very short exposure time. In cases with such brightness differences you normally make an exposure series as shown here (with tripod!) and use high dynamic range techniques and exposure stacking which is nowadays quite straightforward to use. However with the moon and a bright planet (Mars, or Venus) below the moon this does not work for several reasons:

• The long exposure gives 'stripes' for the stars, planets and the moon as well, because the earth moves
• Even more problematic for the same reason is that the moon, stars and palnet change position across the image between exposures
  
• The exposure difference is too extreme. Even stacking the cropped moon alone with over 10 images does not yield a nice image

As I will explain here, there is a 'dirty' solution to this problem, which is not as realistic as exposure stacking, but gives a result that is quite true to the experience of the viewer. In short: the washed out moon needs to be cleaned (and not as bright), as well as planets and stars visible as stripes. From the end of the exposure series you copy in a layer and set it to blend mode 'lighten'.

Advanced Photoshop technique for image restoration: remove erratic backgroud structures

 

This new Photoshop technique will allow you to remove any erratic, chaotic background patterns, caused by old printing machines ('random dotted pattern') or visible paper structures (fibers, depths), with the least possible blur. Note that there are various methods for recovering halftone prints from newspapers or color magazines (with the fast fourier transformation method) covered elsewhere. The images have in common that they show at the highest zoom a kind of chaotic leopard pattern. What you would like to do is to lighten the spots, and darken the background, so that they merge to a uniform color. The difficulty is to get a selection that is exactly right.

Die Teufelsmauer - ein einzigartiger Geotop und vergessene Perle am Harzrand - mit Karte

Die Teufelsmauer in Sachsen-Anhalt liegt am Ostrand des Harzes. Sie ist eine vergessene Perle, für Wanderfreunde die skurrile Felsformationen lieben. Manche kennen die Teufelsmauer bei Neinstedt, den bekanntesten Teil. Was viele nicht wissen, ist das die Teufelsmauer sich in 3 Teile über 20 km ausstreckt. An jeder diese 3 Orte kann man jeweils eine größere oder mehrere kleinere Wanderungen machen. Für unsere Familie hat sich dieser Gegend als sehr praktisch für kleinere Kinder herausgestellt, da die Strecken kurz sind und es viele Einkehrmöglichkeiten gibt: wenn man zurück läuft, sehen die Hinterseiten der Felsen nochmal komplett anders aus. Langweilig wird es, trotz wenige Kilometern, nie. 

The mystery of the dark rainbow

Many years ago I saw a "dark rainbow". A perfect bow,  a dark curved band in the air, the same width and same shape as a normal rainbow. It was appearing in the south, where the dim sun also appeared, around 11:00 am. Later that day, my social network confirmed that others had seen this mysterious phenomenon as well. Mysterious indeed; nobody knew what it was or what could be the physical explanation! I contacted several meteorologists by email, but I never received an answer. All those years, none of the meteorological books that came in my hands provided a even the smallest clue... What could it have been?!!

Lego einfach reinigen

Altes Lego auf dem Dachboden? Total verstaubt und verschmutzt? Mein Versuch so was recht unkompliziert sauber zu bekommen, hat so gut funktioniert, das ich ein paar Tips gerne hier teilen möchte.

Worterfindungen 2020

Nach langer Zeit habe ich  unser Whiteboard in der Küche mal komplett sauber gemacht, und dabei zwei Worterfindungen aus 2020 weggewischt, die ihre eigene Geschichte haben.

Amazing photos of melting glaciers and mountain summits in the Italian Alps

 

This church in Trafoi is still standing. The big hotel in the back had a fire and wasn't rebuilt. But what is really missing in the background is the big glacier!
Left image: SLUB / Deutsche Fotothek / Möbius, Walter; Right image: J. Everaars

When I visited the Italian Alps for a scientific project on the effect of climate and land use change on pollinators, I tried to re-picture some of the sites I found on historical photos. Here are some of the results.