Aurora season

Spring is aurora season, and just before midnight last night a display of the northern lights lit up the sky. Taking a test shot from the window confirmed the alert from my phone app, so I headed out the door. The display had already started to subside once I’d defrosted the car and got to a dark spot. But I got there in time to capture a sequence of 50 frames. Enough for a (very!) short time-lapse…

A meteor can be seen around half way through the time-lapse sequence, just to the right of the Andromeda galaxy. You might need to download the HD version to make it out… Here’s the ‘test’ shot taken before heading out. The display was pretty strong at this point…

Aurora Season: Aurora Borealis from Yorkshire, England

Image details: Nikon D7000Nikkor 35mm f1.8G at f1.8. All shots were 10 second exposures at iso 640. Edited and animated in Photoshop CS6.

Standing on the Shoulders of Giants

Standing on the shoulders of giants - Orion rises over Helvellyn in the English Lake DistrictOrion rises over the jagged slopes of Helvellyn in the Lake District. The figure standing in silhouette on England’s third highest mountain is dwarfed by the constellation.

Taken from the lower slopes of Striding Edge, a friend wilfully volunteered to stand on the edge of a precipice as a setting crescent moon illuminates the distant snow-capped peaks.

Using the barn door tracker at half speed allowed me to effectively double the exposure time before the motion blur of either the ground and the sky became noticeable.

This technique combined with the altitude and the dark skies of Cumbria helped bring out the classic deep sky objects. The Great Orion nebula, Horesehead nebula and Flame nebula all make an appearance. With a hint of Barnard’s loop just visible.

The really comes into it’s own with this type of wide angle constellation shot. Making the reddish gold of Betelgeuse and the brilliant white of Rigel stand out spectacularly in the scene.

Image details: Nikon D7000Nikkor 35mm f1.8G at f2.8. 30 seconds at iso 1600 using didymium filter and softon filter. Tracked at half speed with barn door tracker.

Auriga

Auriga with nikon 35mm f1.8 G lens

Imaging full constellations is something I’ve been itching to do since trying the new softon filter. So last night I set off in search of some darker skies armed with a borrowed Nikon 35mm f/1.8G lens. The constellation of Auriga was the target as it’s perfectly placed overhead at this time of year, and imaging large targets overhead is much preferred. (Trying to remove gradients from targets lower down is a real nightmare).

With an exposure time of 22 minutes, the detail visible in the shot is pretty impressive. The centre of Auriga holds two open clusters, M36 and M38, which sit beside a couple of faint nebulae; the Flaming Star nebula, and the less catchy IC410 – an area which could be an excellent target for the 180mm lens at some point.

The lens itself worked like a charm. Stopped own to f4 it’s super sharp, and the light weight makes it easy on the barn door tracker (200g vs 800g for the 180mm). I also had a pleasant surprise when it came to stacking the images as I realised I’d also caught the California nebula in the upper right of the shot!

Hoya Softon A filter for astro  imagingTo get the glowing star effect I took nine 2 minute photos without the filter, then two shots with the softon filter in place. I stacked these separately in DSS and combined them in Photoshop with the softon layer set to ‘screen’.

This side-by-side caparison of 2 minute shots of Capella demonstrates the filters effect. The medium to bright stars stand out much more, as well as their colours. The filter also dims the background stars making the constellations pop out even more.

Image details: Nikon D7000Nikkor 35mm f1.8G at f4. 18 minutes (9 x 2 minutes) at iso 800 using didymium filter, plus 4 minutes (2 x 2 minutes) at iso 800 using softon filter. Stacked with Deep Sky Stacker and Photoshop. Tracked with barn door tracker.