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!).
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..!).
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.
All images were 2 min videos, recorded using FireCapture, processed in AutoStakkert, Registax 6 and Photoshop CS4.
We’ve had some poor weather this winter so far for astronomy, but we’ve had some clearer nights in the last week, but with the moon at a fairly full phase. So I’ve been working with the 14″ SPX350 in honing my high resolution lunar work a bit.
I had two fairly average sessions working with the ZWO camera in unfiltered mode, but suffered a lot from poor seeing (potentially due to thermals from houses I image over) especially with stacks coming out with “ghost craters”. However, for this run of images, I used an Astronomik ProPlanet 742 filter I have just purchased (this is a near IR filter passing wavelengths longer than 742nm).
This has given a very good set of results – with three images surpassing the resolution I’d previously been able to get – and working at a focal length around 3200mm too by using a Meade series 4000 barlow lens in front of the camera and filter (giving a resolution of about 0.24″/pixel). Previously, I’ve only got good results at prime focus. From a first time using it, it certainly appears that this filter does help with larger apertures where seeing is not perfect. Images, while not totally unaffected by seeing, seemed a lot more stable in terms of high speed jitter or double vision on craters.
Images were taken around 98% illumination so all the images are from areas around the eastern limb of the moon – with limited targets available and with cloud rapidly rolling in, the session was somewhat curtailed!
Grimaldi, Hevelius, Cavalerius:
Phocylides, Nasmyth, Wargentin and Schickard:
A long time since the last post (and still needing to properly process the lunar eclipse images I took at the end of September) I finally got the 14″ re-mounted and collimated for some lunar work.
Images were taken through an Orion Optics SPX350 at f4.52 (prime focus) using a ZWO ASI120MM. Images were stacked with Autostakkert, processed in Registax 6 and Photoshop.
First up: The South Pole region (including Tycho, Clavius and Moretus)
Copernicus and surrounds:
Rupes Recta in Mare Nubium (also showing Rima Birt and the lunar dome Kies Pi):
Mare Imbrium and Plato: