Astrophotography by Anthony Ayiomamitis

Star Trail Image Gallery

One of the most basic types of astrophotography and yet equally stunning is that involving star trails, particularly around the celestial poles or immediately due east or west. In addition to capturing the motion of stars around the north pole which are circumpolar and, hence, never rise or set, we also have the ability to capture seasonal constellations and stars in such photos, thus allowing for different opportunities during different seasons. Star trail photos also provide direct evidence that our planet rotates and does so at a rate of 15 per hour. Furthermore, by studying the arc for a particular star, especially as far away from the pole as possible, one can indirectly estimate the length of the (total) exposure which often ranges from seven to eight hours in duration and is totally dependent on the end of astronomical twilight one evening and its onset the following morning.

Many star photos are centered on Polaris, a double star system which represents our quickest means to locating the north celestial pole, for it lies less than 1.0 from it, and is an excellent starting point for the polar alignment of a telescope (and finding your way home if you are lost!). Due to the extended length of the typical exposures involved, the best film for such work is Kodak Elite Chrome (ISO 100) whose reciprocity failure is nearly zero or Fujichrome Velvia and Provia (ISO 50 and 100) emulsions with equally impressive curves! With respect to equipment, it is rudimentary, for a camera with extended exposure capability is required along with a firm tripod and shutter release and locking cable. It is also preferable that the camera used have a mechanical shutter so that battery consumption and power does not become an issue during mid-exposure. The final requirement is a location with dark skies - the darker the better so that the trails and their colouration will be as bright and contrasty as possible - with, preferably, an interesting foreground which can be used to enrich the final result.

Note: The impressive but abandoned Church of Saint Ioannis Prodromou below was built in 1919 and lies within a short walking distance from the Temple of Poseidon at Sounion. The church was never granted a permit for its operation following the objections of the Department of Antiquities (Greece) due to the fact that its construction included materials taken from the nearby archaeological grounds at Sounion and, more specifically, the Temple of Souniadas Athenas built during the 5th century BC and which measured 19 x 15 meters. Locals claim the church and other related buildings in the immediate vicinity which also fall under the embargo due to the efforts of the Department of Antiquities are haunted. Nevertheless, this impressive structure has stood well during the nearly one hundred years since its construction and during which it has remained abandoned but has managed to remain a very photogenic monument.


Image Details
Star Trails Over Agios Ioannis Prodromou (Sounion)
Imaging Details
Proper Star Name:
Polaris

Bayer Letter:
Ursae Minoris

Tycho Catalog:
TYC 4628-237-1

SAO Catalog:
SAO 308

Luminosity
2290 +/- 282 x Sun

Distance:
431 +/- 26 light yrs

RA / Dec:
02h 39m 31s /
+89 17' 39"


B-V Color Index:
+0.570 mag

Magnitude:
1.98
Date:
July 03-04, 2014
22:15 - 03:25 UT+3


Location:
Sounion, Greece

Equipment:
Canon EOS 350D
Canon EOS EF-S 18-55 mm
    @ 21 mm / f5.6


Exposure(s):
312 min (208 x 90 sec) (RGB)
009 min (006 x 90 sec) (Dark)
ISO 400
JPG Fine Image Format
3456x2304 Image Size
Continuous Servo Mode


Software:
Startrails V1.1
Photoshop CS5


Processing:
Dark Frame Reduction
Layers and Lighten
Resampling
Unsharp Masking
JPG Compression