Tag Archives: ASI120MM

Nov 2017 Lunar Mosaic

The 4th November 2017 gave me clear skies with a very bright moon in the sky – this gave me  good opportunity to use the rebuilt 14″ Newtonian scope for some imaging work, now that the scope truss tubes have been correctly milled down to the right length. 

Using the ASI120MM camera with a 742nm nr-IR filter, I imaged the moon at its native focal length (1582mm), using Firecapture to grab the video. The data totalled 56GB in all!

The finished mosaic consists of 18 frames: each of these was the result of stacking the best 12%  (quality-wise) of 3000 frames. Each of the frames were 0.18ms each (with gain set to 54), and were captured at around 31 frames per second.  To try to avoid issues with exposure mismatch, all the exposure details were kept identical throughout the 36 minutes  or so it took to complete the whole set of videos across the face of the moon.

99% Moon on 2017-11-04
Mosaic of 99% Moon on 2017-11-04 at 80% resolution (3MB image size)

The videos captured were aligned and stacked using Autostakkert2, and each of the stacked images were processed using identical wavelet settings in Registax6. 

To create the mosaic itself, I took all the images into Microsoft Image Composite Editor (ICE) and let it get on with the process of aligning and stitching the images together. It did a remarkably good job! I had also tried the Photomerge function in CS4, but ICE did a better job here: Photomerge was good but left a couple of slight merging artifacts – misalignments on the limb, mostly. 

Final processing took place in Photoshop (smart sharpening, levels, curves, etc) with the result being a 20Mpixel image weighing in at 7+ MB for a high quality jpg. Here, I’ve reduced the image to 80% of the original resolution to aid web viewing!

Images were taken starting at 2215UT from West Oxfordshire, UK. 

Lunar Imaging Gallery – 16th May 2016

Some further lunar work – as before I worked using the ASI120MM in combination with a 2x Barlow lens and the 742nm near-IR filter through the 350mm Newtonian.

A productive evening, with six images of good quality in what was at times fairly good seeing – I would like to try running at a slightly higher scale (by using a different Barlow). i do have a 4x Imagemate, but I’m not sure the quality or the resultant focal length would work quite as well.

As it turned out, this was an evening where I bagged a few of the double ringed (concentric) craters on the moon, as well as some interesting Rille features and domes.

Images are as follows:

Clavius with Longomontanus, Scheiner and Blancanus – a good amount of detail in this image and I’m especially pleased with the detail within Rutherfurd (on the southern edge of Clavius). Street M is visible with a small concentric craterlet within.

Longomontanus and Clavius, 2016-05-16

Moretus, with some very good detail coming out of the wall and surrounds. The lunar south pole region (with Newton tucked just behind the hills) is to the bottom of the image.

Moretus, 2016-05-16

Copernicus – a classic lunar crater, and one where I’ve got a much better result than I’ve previously acheived. I particularly like the collapsed edge visible to the south – perhaps a little more scale might just let me sharpen up the detail within the crater a little… Also visible are the Hortensius domes (to the left in the image) lying just to the north of the crater of the same name – lunar domes are shield volcanoes which often have a small craterlet at the peak.

Copernicus, 2016-05-16

 

Rimae Hippalus and surrounds. So much going on in this region – bullialdus by itself is a nice looking crater, and nearby the complex rille structures of Rimae Hippalus cut across Hippalus and the surrounding regions, leading up to Agatharchides. The lunar dome Kies Pi is easily visible and concentric crater Marth in Palus Epidemarium is also present in the bottom right of the image.

Rimae Hippalus and Surrounds, 2016-05-17

Another busy nearby field, showing Pitatus, concentric craters Hesiodus A and Marth. Lots of rilles also visible, including Rimae Hippalus, Rimae Ramsden, Rima Hesiodus, rilles in Pitatus, and Rima Campanus cutting between Campanus and Mercator. Kies Pi is again obvious.

Mare Nubium and Palus Epidemiarus, 2016-05-16

A view north of Bullialdus including the interesting “rippled” texture between Darney and Euclides.

Bullialdus and Mare Nubium, 2016-05-16

The last two make a rather nice mosaic, though this was a quick job and I haven’t tried too hard to eliminate the edge of field noise, or the slight mismatch between levels.

Bullialdus Region - Mosaic

Transit of Mercury, 9th May 2016

On 9th May 2016, Mercury transited the sun as viewed from Earth for the first time since November 2006. The transit was well timed for observation from The UK and Europe, starting at 11:12UT and ending at 18:42UTSolar Imaging Setup. I attempted to view and to photograph the transit using both my WO FLT110 with a Herschel Wedge from Lacerta, as well as visual work through the Takahashi FC60.

To image the eclipse, I used a combination of the WO FLT110 working at native f7 using the Herschel Wedge, with ND3.0, IR/UV blocking and Wratten #57 filters. Situated behind this combination was the ASI120MM camera – the plan being to take video captures of the event, processing into images later with Auostakkert/Registax.

However, British weather being itself, I only had a very short window of clear sky at the beginning of the transit during which I could grab one decent shot showing Mercury (bottom left), AR12542 (top) and AR12543 (lower), and with AR12544 developing at the top left. This image made it onto the Meridian (West) news at 6pm that evening, and is on Simon Parkin’s Mercury Transit blog post as well.

Transit of Mercury, 2016-05-09 1250 UT

After this 10 minute spell of clear(ish) sky, I had very little opportunity to see the transit again – there was a short period here and there where I was able to visually observe Mercury and the sunspots on the disc, but by 3pm I was completely clouded out, with rain following later in the evening….

Clouded out for the Transit of Mercury...

Lunar Imaging – 17th Mar 2016

I took the opportunity to do some further imaging of the Moon and Jupiter during a clear evening on the 17th March – as is common, the moon was high, and the transparency wasn’t great for any narrowband work, and as such it gave me an opportunity to work more on some high resolution work.

The seeing wasn’t great, and I took a different approach to imaging this time by using subframes on the ASI 120MM to get a high frame rate and allow large numbers of frames to be captured (thus increasing the chance of capturing good frames).

Images as below are of Clavius, Tycho, Rupes Recta (the Straight Wall) and Rima Birt, and Vallis Alpes (Alpine Valley) with the central rille (just!).

Clavius 2016-03-17, 20:02UT

Tych 2016-03-17, 20:27UT

Rupes Recta and Rima Birt 2016-03-17

Vallis Alpes 2016-03-17, 20:18UT

Jupiter – March 2016

Planetary work is not really my strongest skill in astrophotography, but with Jupiter near it’s highest in this and the past few years, it is well placed for photography from the UK.

Additionally, this is one of the first chances I have had to get images with the large 14″ reflector using my ZWO ASI-120MM. I chose to use the Astronomik 742nm Near-IR filter to try to improve the results: on both occasions it has resulted in much better resolution than with unfiltered white light. In addition I used a Meade Series 4000 2x Barlow lens. With regard to conditions,  I think I’m a little limited by my observing location where I have to observe over the top of our row of houses – the thermal currents (including from boilers, open fires, etc) are likely to do little to help the seeing here..!

First image is from the 17th March during Callisto’s shadow transit (taken at 23:08UT)  – Callisto itself is also visible at about 7 o’clock (and clearly resolved into a disc – at 1.5″ the seeing was clearly not so bad..!).

Jupiter 2016-03-17, 23:08 - with Callisto and Shadow Transit

Second image was taken on 22nd March 2016 – the results weren’t quite as sharp as those from the 17th. Unsure if this is a focus/collimation issue, or if the seeing just wasn’t as good. The processing is a little heavier to try and bring out the cloud contrast where possible too. Collimation of an f4.5 scope is fairly critical, and any slight shift can reduce image quality quickly. Equally, at f9, focusing is tricky with a fairly dim extended object – this is something I need to work on in the future – a Bahtinov mask is on the list of makes for when I have successfully rebuilt this scope.

Jupiter 2016-03-22, 22:43:52

All images were 2 min videos, recorded using FireCapture, processed in AutoStakkert, Registax 6 and Photoshop CS4.