Exposure time 8,0 Sec.

Bruges by night

Submitted by Jürgen Tenckhoff on Fri, 01/22/2021 - 15:41

Venice of the North is called Bruges in Belgium in the Merian. And if you think of the well-known novel by Thomas Mann, Death in Venice, you also understand the title of the film "Seeing Bruges ... and Dying?" From 2008 by Martin McDonagh (screenplay and direction). But that ends the initial similarity between film and novella - while Thomas Mann draws the famous writer Gustav von Aschenbach to Venice, in Martin McDonagh's tragic comedy the two hit men Ray and Ken, masterfully played by the well-known actors Colin Farrell and Brendan Gleeson, travel to Bruges.


Rainbow holograms in art

Submitted by Jürgen Tenckhoff on Fri, 09/25/2020 - 15:47

This example nicely shows the special effect of rainbow holograms: If you tilt them around the horizontal axis, the photo runs through the spectral colors. If you move them around the vertical axis, they show the three-dimensionality of the recorded object. This opens up many possibilities for art projects, since with this method you not only have three representable dimensions but also colors for designing the art object.


Holography with argon laser

Submitted by Jürgen Tenckhoff on Fri, 09/25/2020 - 13:40

White light holograms are generated with coherent laser light (here an argon laser), but they meet lower coherence conditions when viewing. The recorded objects show up in parallel light, so that lasers can be dispensed with. This makes them very suitable for artistic projects.

This test recording was taken in 1979 at the chair for theoretical electrical engineering at the Ruhr University in Bochum.


Rainbow holograms for ID cards and art projects

Submitted by Jürgen Tenckhoff on Thu, 09/24/2020 - 14:43

Rainbow holograms are a special type of white light holograms. The technique for generating rainbow holograms was developed in 1968 by Dr. Stephen A. Benton designed. Rainbow holography uses a horizontal slit and / or cylindrical lenses to remove vertical parallax in the output image. This reduces the spectral blurring while maintaining the third dimension in the observation. If you look at a rainbow hologram that is moved around the horizontal axis, you only see the change in colors.


Comet Neowise above Hennef

Submitted by Jürgen Tenckhoff on Wed, 07/22/2020 - 13:00

Comet C / 2020 F3, Neowise, was difficult to photograph above Hennef. Haze and light pollution prevented several attempts and the planned beautiful image composition with Neowise over Blankenberg Castle was unfortunately not possible. But tonight it was finally time. The lower temperatures kept the haze over Hennef at bay, the sky was relatively clear ...


Color-Key pictures of Frankfurt am Main

Submitted by Jürgen Tenckhoff on Mon, 11/17/2014 - 18:45
Frankfurt am Main, Düsseldorf, Cologne and Bonn on the Rhine, Passau on the Danube, Hamburg on the Elbe - night shots in these cities are particularly impressive as color-key images due to the reflections in the rivers and waters. Long exposures create a silky water surface that makes reflections appear particularly effective. However, the transformation from a color image to a Color-Key picture with Adobe Lightroom or Photoshop is relatively easy compared to the creation of suitable source material, where a lot can happen. If e.g. at the crucial moment a pair of ducks land on the calm water surface and generate waves over waves ... then it is time to wait, wait, wait.