Edwin Jones

Edwin Jones

Posted on 03/13/2012

Photo taken on March 12, 2012


Long exposure
star trails
wide angle
north star

Authorizations, license

Visible by: Everyone
All rights reserved

164 visits

Roof Open to the Stars

Roof Open to the Stars
The Shot

Note there is no Exif info for this shot as the Startrails stacking software removes it.
This is back to Star Trails season. The moon was not due to rise until 10.45 pm and will get later for the next week.
This was taken in an abandoned building on a lane between Puerto del Carmen and Tias in Lanzarote. The roof is open and the front is open. There was light from Puerto del Carmen behind me. The foreground is lit by a combination of that light, a few passing cars and light painting with a torch at the end of the sequence.
There are 2 methods, either one long exposure of 20 minutes plus or a lot of shorter exposures later blended together. The problem with the first is if something goes wrong such as a walker with a flashlight or condensation you can lose the whole thing so I went for the second. It would normally be very time consuming to blend all the pictures together but there is now free software available to do it for you at www.startrails.de/html/software.html
With the method of stacking together shorter exposures noise is not such an issue so I turned off the Cameras noise reduction settings. If these are turned on it doubles the exposure length as a second image is taken automatically of the same length for the noise reduction process. Noise was corrected later with software. Also a higher ISO is required to get the stars to register in 30 seconds so I used ISO 800 and f4. The white balance was set at daylight.
The circular pattern is formed by pointing the camera towards Polaris the Pole Star near the Plough. As the Earth turns stars more above the pole do not appear to move as much as those more above lower latitudes. I had with me an HTC Android Smart Phone with the Google Sky App. This enabled me to locate the pole star while there was still light.
The light on the right is the light from the small town of Tias to the north east.
The image was taken over 70 minutes with 140 images of 30 seconds exposures each stacked with the startrails software. I set the camera to continuous mode and used a wireless shutter release to lock the shutter so the exposures were taken continuously without needing to touch the Camera
- Sony A700.
- ISO 800, f4, 30 seconds, 10mm.
- Sigma 10-20 lens.
- Tripod.
- Wireless Shutter Release

I started with opening the Raw file for one image where the light painting of the foreground came out best. Improvements were made in Camera Raw including exposure clarity and Vibrance.

I wanted to then make separate adjustments to the foreground and the Star Trails. I tried various selection methods but the slats in the roof made that difficult so in the end used a mask.

The foreground was improved by reducing brightness and using Topaz to bring in more detail.

The foreground was saved as a jpeg to go with the other images in the stacking software and blended with the foreground from the other images.

For the Star Trails the stacking software works on jpegs which are then saved as a Tiff. I opened this in Photoshop

After opening in Photoshop general adjustments in curves to increase lightness and contrast and bring up more star trails. The mask was inverted and used to make adjustments only to the sky.

Duplicate layers were brought up to apply Topaz Adjust Vibrance presets, Detail strong 2 with some adjustments to further bring out the Star Trails.

A colour Balance layer was used to bring down a purple hue

Noise reduction was done with Noiseware Pro


For Licensing and more pictures see Edwin Jones Photography