Tuesday, April 2, 2013

Making of a star trail

March 2013 was a good month for me, it allowed me to relax at my own terms!

Most evenings I had the leisure in which I tried to learn and explore - how to capture stars and how to make a photograph of star trail.

Before starting up, I read few articles to get the basic know how. I found many articled over net - courtesy Google and lists of blog that I follow regularly. In particular I read part 1 and part 2 of "All about night photography and photography sky" (the native article is in Russian). Also I closely watched many photographs by the author of the above mentioned articles and by Lincoln Harrison. But there is a big gap between reading/watching something and producing the same thing by own - same as the difference between theory and practical. So things were there to challenge me - they were determined and so was I.

The first big step was to shoot in manual focus mode. I never tried manual focus in my life before, I was afraid to manual focus. I took a deep breath and turn my lens into manual mode and focused to the infinity by rotating the focus dial of my lens. Steps to be followed (that I followed) are:

1. Turned the lens into manual focus mode (as mentioned above) and focused into infinity (for stars, it produce good results)
2. Use wide angle to ultra-wide angle lens and stick to the wider part, I had my Nikon AF-S DX 18-105mm f/3.5-5.6G ED VR lens and I used 18mm.
3. Set the aperture as wide as possible, f/2.8 or wider is capable to produce good results, with my lens I was permitted to use maximum of f/3.5 only and so I did. They say, work around limitations and you will be able to present the best!
4. Shutter speed that I used either 25 sec or 30 sec. For star trail the 25 sec to 30 sec of exposure for each shot is good enough. If the intention is to capture only stars and to avoid the movement of stars then the thumb-rule is to stick with a shutter speed of (600/focal length) sec e.g. if you are using a 24mm focal length then a shutter speed of 25sec will be good enough to have a well exposed stars and without any movements. Remember, this thumb-rule is applicable for full frame system. For cropped system, you need to further divide by 1.5. Also remember, there are exception as this is only a thumb-rule.
5. Pump ISO on higher side to increase light sensitivity of the camera sensor. The recommended value is ISO 1600 to ISO 6400. I was sticking to ISO 800 to ISO 1600 zone to avoid the light pollution of the city, higher ISO was blowing out my horizon. 
6. Mount the camera into a sturdy tripod (a compulsion) and set the camera into interval shooting mode (obviously after few test shots) to shoot 200 to 400 shots (preferable in RAW) or more.
7. Make sure to have a fully charged battery and preferably one back-up battery (fully charged) and an empty memory card before starting the session. My one fully charged battery and an empty 8gb card was good enough for a session of 400 odd snaps.

That was all about shooting and the most important part. The next part is about post-processing and relatively easier part. Steps are:

1. Import all your images from memory card to your computer, open them in your preferred software (in my case it was/is Adobe Lightroom), apply the necessary lens correction and appropriate white balance. 
2. Export your images as JPEG, do not scale down the image size - keep the original.
3. Download Startrails or StarStaX from web and install - both are freeware.
4. Open all your images through the downloaded/installed software and ask the software to process. There are very few sliders/options which you can play with as per your taste. Startrails allows you to make animated output as well.
5. Once the processing is done, you can save the image either as JPEG or TIF or any other format. If you want to further enhance the exposure/contrast of your image then play with the TIF output. 

That's all!. I heard that the same can be achieved using Photoshop, but I guess that will be a lengthy process with lot of layering ans masking. Here no hassle of Photoshop!

My first trial yield this image - around 120 images processed in StarStaX, the foreground is bit boring (actually missing!) but honestly I was trying to get the know-how only.

First trial with Star trails
After achieving the above, the beauty of night, orange colored moon rise at midnight, bites of mosquitoes and continuous experimentation with star trails made the following nights more fun-filled and productive.


Around 420 shots were stacked together

Around 250 shots were stacked together


Over 400 images (precisely 443) from 10.45 pm to 2.30 am on a clear starry night (due to an afternoon shower) resulted the above image. Processed in StarStaX. 
EXIF data: Nikon D5100 with Nikkor AF-S DX 18-105mm f/3.5-5.6G ED VR lens; 25 sec (each), f/3.5, ISO 800, 18mm.

A long way to go before making an AWESOME one!

Stay tuned with my works at 500px | Flickr. Hang out with me on Google+ | Twitter | Facebook.

Please feel free to comment. All comments (criticisms & appraisals) are welcome. Please do not reproduce the images for commercial purposes without prior permission.

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