Andromeda Galaxy II

Andromeda galaxy with barn door tracker

After being blown away by my first attempt at the Andromeda Galaxy, I couldn’t help having another go with the improved barn door tracker, this time using longer exposures of 80 seconds, and a lower iso of 800. The resulting image has a lot more detail and much less noise than the original, despite being taken from the back garden with plenty of light pollution and a rising moon. Click here to view the image at 100% scale.

Having experimented with different ISO speeds on the Nikon D7000, I’d say that iso 800-1000 offers the best balance between noise and sensitivity for astrophotography.

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 64 minutes (48 x 80 seconds) at iso 800. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

Below is a side-by-side comparison between the original image (5 x 30 seconds at iso 1600) and a recent image (18 x 80 seconds at iso 800).

andromeda galaxy exposure length

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Comet Lovejoy – C/2013 R1

comet lovejoy C/2013 R1 and M44 beehive cluster

I managed to grab a few shots of comet Lovejoy (C/2013 R1) as it flew past the Beehive cluster (M44) in the constellation of Cancer. Lovejoy is one of four bright comets currently visible in the early morning sky, including the much anticipated ISON. Unfortunately I don’t have the will power to get up at 5am to enjoy the show, but Lovejoy hangs much higher in the sky at this point, so appears much earlier. (These images were taken between 1 and 1.30am local time).

The comet is still pretty dim at the moment at magnitude 6.2, and invisible to the naked eye. But it should continue to brighten for the next month or so, hopefully developing a more pronounced tail as it dives toward the Sun.

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 3 minutes (6 x 30 seconds) at iso 800. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

comet lovejoy C/2013 R1 barn door trackerA single 30 second exposure was enough to bring out the comet’s intense green colour caused by poisons gasses spewing from the core. I captured a total of 40 exposures at 30 second each stacking them in Deep Sky Stacker to create the 20 minutes image shown here.

Stacking the images centred on the comet results in the streaking of the background stars due to the huge speed of the comet (roughly 100,000 mph). DSS does give the option to stack the comet and the stars separately (so both are sharp). This sounds great, but in practice didn’t work too well and I actually prefer the original 3 minute exposure stacked on the stars.

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 20 minutes (40 x 30 seconds) at iso 800. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

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Comet Lovejoy Update 30th November..

Comet Lovejoy is best seen in the hours before dawn, where it sits nice and high in the sky. But thankfully for people like me who enjoy their sleep, it’s also now visible in the evening sky as well. It appears lower down at this time, so the conditions aren’t as good, but it has allowed me to revisit the comet to see how it’s doing as it nears the Sun…

Comet lovejoy galaxy barn door tracker

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 5 minutes (10 x 30 seconds) at iso 800. Using didymium filter. Stacked (to stars) with Deep Sky Stacker and tracked with barn door tracker.

The comet, seen here gliding past the Sunflower galaxy (M63), has grown a pretty huge tail in the last month! Although I’ve found long exposures of the comet difficult to take due to its massive speed, the image below with the levels pushed to the maximum shows some nice detail in the tail.

comet lovejoy tail barn door tracker

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 9 minutes (18 x 30 seconds) at iso 800. Using didymium filter. Stacked (to comet) with Deep Sky Stacker and tracked with barn door tracker.
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Orion

orion nebula M42 barn door tracker

Orion is one of the most recognisable and celebrated sights in the winter sky. The constellation has been documented, worshipped and woven into fable and legend for thousands of years. The supergiant stars Betelgeuse and Rigel are two of the brightest in the sky, and the vast amount of nebulosity in the region make Orion an excellent target.

I tried my hand at capturing the legendary Orion nebula (M42) in the sword region. The nebula is among the brightest in the night sky, so I was optimistic for a pretty good result. But seeing it final result stacked in DSS with all its stunning detail, I couldn’t help but be blown away once again!

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 56 minutes (112 x 30 seconds) at iso 800. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

horsehead nebula taken with barn door trackerOrion’s belt also contains the famous Horsehead nebula, which I thought would be neigh on impossible to capture due to its faintness and fairly low position in the sky as seen the UK. It’s a target made even tougher due to its red colour, which regular unmodified cameras don’t capture well.

It took the longest exposure I’ve managed to date (1 hour 12 minutes) to draw out the detail, but the final stacked image just about shows the Horsehead nebula, along with the beautiful flame nebula.

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 72 minutes (144 x 30 seconds) at iso 800. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

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Triangulum Galaxy

Since testing out the new Nikkor 180mm f2.8 lens on the Andromeda galaxy, we’ve been cursed with almost 3 solid weeks of cloud and moonlit nights. This is pretty typical, as anybody who’s just bought some new equipment will tell you.

The stars finally came out for an hour or so last night, allowing me to grab some shots of the Triangulum galaxy (M33). Being much smaller and fainter than the Andromeda galaxy (magnitude 5.7 vs 3.4) I went for a MUCH longer exposure, taking 50 shots at 80 seconds each, for a total of 1 hour and 6 minutes.

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 1 hour and 6 minutes (50 x 80 seconds) at iso 800. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

The lens did a great job once again. Below is a side by side 10 minute exposure comparison between the 50mm f1.8 with the new 180mm f2.8 lens. As you’d expect, there’s a massive difference!

Messier M33 triangulum galaxy 50mm f1.8 vs 180mm f2.8 barn door tracker

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Andromeda Galaxy

First attempt at imaging the Andromeda galaxy with the new Nikkor 180mm f2.8 ED Ai-s lens. I was able to grab just 2.5 minutes of exposure time before the clouds rolled in, but the resulting image stacked in Deep Sky Stacker blew me away!

The lens is incredible. It can be shot wide open at f2.8 while still producing sharp contrasty images, with very little coma. There is more detail visible in a single 30 second exposure with this lens, than a full 5 minute exposure with the 18-105mm. The spiral arms and dust lanes stand out nicely in the final image, with the two satellite galaxies M32 and M110 easily visible. The colour the lens produces is another welcome improvement over the flat colours from the old lens, and something I hadn’t expected.

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 2 and a half minutes (5 x 30 seconds) at iso 1600. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

andromeda galaxy evolution

This sequence shows the progression over the last 2 months, from single 10 second image, to the most recent tracked and stacked image. All images were taken with the Nikon D7000 at iso 1600:

  1. View – Single frame with Nikkor 50mm f1.8, on fixed tripod. 10 second exposure at f2.5.
  2. View – 30 frames with Nikkor 50mm f1.8, on fixed tripod, stacked with DSS. 5 minute exposure (30 x 10 seconds) at f2.5.
  3. View – 3 frames with Nikkor 18-105mm f3.5-5.6, tracked with barn door tracker and stacked with DSS. 5 minute exposure (3 x 100 seconds) at f5.6.
  4. View – 5 frames with Nikkor 180mm f2.8 ED Ai-s, tracked with barn door tracker and stacked with DSS. 2.5 minute exposure (5 x 30 seconds) at f2.8.

The key to improvement was building the barn door tracker which allowed for longer exposures, along with Deep Sky Stacker to reduce noise and bring out the details. I should be able to improve on the sequence even further once the weather picks up!

Update…

After 3 weeks of bad weather and moonlight, I eventually had another go at the Andromeda galaxy. The final image (below) is a definite improvement as the galaxy was near zenith at time of shooting, so there was less atmosphere in the way. At 6 minutes and 30 seconds (13 x 30 seconds) it’s also a longer exposure. I think it would be possible to improve still further, but I’d need to go to a dark sky site and use ‘sub frame’ exposure times longer than 30 seconds.

andromeda galaxy M31 barn door tracker

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 6 and a half minutes (13 x 30 seconds) at iso 1600. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

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Cygnus nebulae

This is easily the best astro shot I’ve managed to date. Taken using a combination of the cross filter and the new didymium / red enhancing filter which really draws out the nebulosity in Cygnus. The North America nebula, Pelican nebula and Butterfly nebula can all be seen in this 1000 second (10×100 seconds) exposure.

I’ll probably try the same shot again, but without using the cross filter. I think it can work well in single exposures, but Deep Sky Stacker has a hard time with multiple exposures, and the effect gets a bit too distracting.

Details: Nikon D7000, Nikkor 50mm/f1.8 at f4. 16 minutes 40 seconds (10 x 100 seconds) at iso 800. Using cross filter and didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

north american nebula red intensifier

A few days later I had a go at imaging the North America nebula with the Nikkor 18-105mm/f3.5-5.6 lens. I accidentally took the photos as 70mm, so there isn’t much difference to the 50mm; just a lot less light gathering power!

Details: Nikon D7000, Nikkor 18-105mm/f3.5-5.6 at 70mm and f5.2. 18 minutes (12 x 90 seconds) at iso 1600. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

Update…

Since purchasing the Nikkor 180 f2.8 lens I’ve had another go at the nebulosity in the Sadr region. I’ve been experimenting with ISO settings, taking this image at ISO 6400. However I think I’ll stick to lower ISOs in the future (1600 and below) as the results at higher ISOs begin to deteriorate.

Cygnus Gamma Cygni Sadr region nebula

Details: Nikon D7000Nikkor 180mm f2.8 at f2.8. 7 minutes (14 x 30 seconds) at iso 6400. Using didymium filter. Stacked with Deep Sky Stacker and tracked with barn door tracker.

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Deneb & Sadr

Rummaging through some old camera gear, I found a neglected looking cross filter from back in my old film camera days. I guess it’s more of a novelty effect filter, but I was intrigued as to what it might do to my star shots. It polished up nicely with a microfibre cloth, so I laid it on the 50mm lens (the filter size is way too small) and took a few shots straight upwards in the direction of Deneb.

cassiopeia crop smallI think the effect works well as long as there aren’t too many bright stars in the frame. Here’s another shot I took of Cassiopeia with several more bright stars, which perhaps gives it a slightly cheesy/tacky look. I think using a 4 cross filter instead of an 8 cross would improve the effect, but overall I like the result. The colours of the stars really stand out with the diffraction of the filter.

As an added bonus, the barn door tracker worked really well tonight, even with longer exposures the stars showed up as sharp pinpoints, without a hint of trailing.

Details: Nikon D7000, Nikkor 50mm/f1.8 at f3.5. Single 30 second exposure at iso 1000. Using cross filter and didymium filter. Tracked with barn door tracker.

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