Dipping a toe in landscape astro photography

August 29, 2012  •  Leave a Comment

I've been dabbling in a bit of astro landscape photography recently for fun - and because I love looking at the night sky. It's a bit of a struggle for me as I'm not a night owl. I'm usually up at 6:00am to go to work. Bed at 10:00 ish. It's not really dark until well after that in mid-summer. Photography at night requires - at a minimum - a camera, a tripod, and a torch. Everything else will just make it better or easier. There are a whole lot of options for gear which improves the technical aspects of a shot, from a cable release for shots longer that 30 seconds, to DSLRs optimised for astrophotography, to manual focus lenses which 'stop' at infinity, so you don't have to focus carefully, to motorised mounts so your camera moves in the opposite direct to the earths rotation, for longer exposures - leaving the sky static in the frame for the duration.

Astro landscape photography uses earth based landscape features - even silhouettes, in conjunction with the night sky.

The first two images here were shot with the moon in shot which makes them a different challenge. Not such a problem for the camera's sensor. This one below, was shot looking over the flooded Arun valley in West Sussex in winter. It's a stitched image using Nikkor 24mm PCE lens. I pushed the exposure to the point where the shadows cut off very abruptly. But overall I like this shot the best so far, even though it was my first attempt some time ago!

The image below  is an evening shot of; (left to right) Altair, The Moon, Venus, Jupiter and before it got really dark. I love the arrangement of the heavenly bodies, but I wish I had a better silhouette in the foreground. I plan to find some locations really close to home for this sort of shot in future. The other issue is that Altair is very small. As a big print it looks great. Not so easy to see on a screen. Nikon D7000, Nikkor 24mm f3.5 PCE at f5.6 

So far, I have learn't/experienced the following in the last few months:

  • It can get cold, even in summer. Extra clothing
  • Standing up with your head pointing up for more than a few short minutes is uncomfortable. Garden chair - preferably reclining - if you're looking at the sky a lot, as part of the shoot / experience.
  • Focusing a modern autofocus lens, manually at night, even with 'Live view' is difficult. Best to pre-mark by testing or note the real infinity focus point (not necessarily what is marked on the lens), or use a manual lens which 'stops' at infinity.
  • Familiar constellations seem to disappear in images which reveal a real 'depth' of stars, e.g. shooting to reveal the milky way.  As these are very bright stars, and as the camera builds a view which includes thousands of dimmer, less visible stars, the bright ones - having hit maximum exposure of R255, G255, B255 early on in the exposure, are 'caught up' by their dimmer brethren and aren't as easy to 'see'.

Unless you are in a very dark environment, getting a crisp starry sky and a visible landscape is difficult. I live in the South of the UK in the yellow bit - See the dark skies map below. My nearest really dark sky is Dartmoor in Devon, about 100 miles away to the west. I will have to get very serious to go that far! 

Dark skies map For the record, I've been shooting with a Zeiss Distagon 21mm f2.8 for many of my night shots. I bought this for my work shooting interiors and photography of people in working environments. I don't need autofocus, but shooting wide open is important to me and this ultra wide lens is, I think, one of the best for corner to corner sharpness wide open. I also have a Samyang 8mm full frame fisheye, which I use in full frame mode on my Nikon D800. I can then crop as I want as this is designed for Nikon DX cameras. I still get a 15megapixel image. 

The image below is in my garden. The edges of the sky are rather bright. It's a mid summer shot, and even though the sky looked velvety black overhead with the milky way very clear, we still have lots of light pollution from nearby towns, so I couldn't expose for long enough to make the milky way really stand out. There is a meteor in this shot at the top of the image. Nikon D800, Samyang 8mm  ISO 2500, at f2.8 30 seconds. 

On the south downs way, I left the shutter open for 4 minutes - hense the star trails. Nikon D800 Zeiss Distagon 21mm f2.8 at f6.3, ISO 2500. I have created a graduated exposure mask to darken the sky as it was so bright at these settings. In fact, in spite of the light pollution, I could barely make out the path in front of me without a torch!

A day or two ago I also discovered Deep Sky Stacker  software. This opened a can of worms! 15 frames of the same patch of sky, plus another 45 frames of 'control' data and some serious image processing later, and my first attempt at a clearer sky above my home can be seen below. This is a 50% crop. On the right, one of the original frames, shot at iso 3200, 15 seconds at f2.8. The one on the left is the processed result from the whole set. I think I have a long way to go to understand how best to use this software, which was really designed for use with telescopes to reveal the best, least 'noisy' image of the sky, not as part of astro landscape photography! If I do use this for landscapes, I imagine I will have to blend the result with a single frame of the foreground to get a pleasing image.

So. I have a lot to learn. None of these images is great. They all have elements I like, but all are flawed too. I hope that in the autumn or winter, I might get clearer skies and maybe If I get lucky with the weather when I'm travelling, I will have learnt enough to get some really good images, like these from Manel Soria I hope to post another blog about this later in the year.

 


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