groberts

Currently unable to carry out astronomy following a knee operation, I'm using the time to reprocess some some old images using my embyronic PixInsight skills. It's early days but I have to say PI is growing on me!

UPDATE - re. nfotis comments above regarding the 294 ZWO & QHY mono cameras. Been looking at this all day + on CN it's clear that the ZWO294MM is very much the successor to the ASI1600MM-Cool, which I and many other people have. This thread on CN is therefore well worth reading if, like me, you're thinking of upgrading: https://www.cloudynights.com/topic/726990-zwo-asi-294-mm-pro-first-impressions-and-test-images/#entry10473357 Warning it's very long but probably points the way forwards for mid-range / price mono cameras for the near /mid-term so worth the time. Graham

I finished this image yesterday, my first mainly processed in PixInsight, and wanted to say thanks to those that helped from time-to-time answering my questions as I battled with PI. I can see the power and benefits of PI but boy is it a x%#*! to learn. In my case after numerous false starts I've spent much of the summer working through various online tutorials (Light Vortex was best but difficult to follow on screen) when finally through persistance and the arrival in the post of Rogilio Bernal Andreo's (RBA) great new box set books Mastering Pixinsight I think I've now completed the first pitch (for those who know rock climbing!) but still have more of the mountain to climb! For anyone starting out + even experienced astronomers, I can't recommend RGA's book enough, it's a game changer. The Deneb-Sadr HII region is rich pickings for astroimaging and I shot this in September. It's actually 90% PI and 10% DSS for calibraiton and stacking (tried PI and it's just too long winded even with batch processing) and inevitably PS to finesse some of the final colours. Anyhow thanks again + for more image info see my website and full resoultion on Astrobin: https://watchthisspaceman.wordpress.com/ https://www.astrobin.com/aph6e9/?nc=user Thanks again, Graham

Thanks I'll take a closer look 🤔

I have an open mind but in what way are they an upgrade + they appear to be only OSC versions, do they do mono? Graham

OK I'm sold on moving to Chroma 31mm filters but have one further small but practical question for anybody that has already made a similar change this. The filters will be going into a ZWO x8 EFW to replace the original bundled ZWO filters: I understand the Chroma filters are thicker than ZWO ones so - will the screws used to fix the ZWO filters be long enough to accomodate the Chroma filters and if not, where could I get suitable / longer replacement ones? Graham

Thanks Adrian that's reassuring. It's just that I haven't used my ASI1600 with the Samyang yet and am considering upgrading my filters to Chroma / Astrodon and wanted to make sure the 31mm would still be OK. As a matter of interest what bandwidth do you use 3 / 5 / 7nm & what sort of exposure times do you need? Graham

OK I get that but for those using the ZWO1600 what size filters are you using and do they work OK?

Currently just playing with this excellent lens using a modded 550D but eventually intend to switch to my ZWO ASI1600MM-Cool + x7 31mm EFW. Just wondering if 31mm filters will be large enough for this fast lens or will I need to go bigger (36mm) to avoid vignetting at say f2.8 or faster? Graham

Interesting - I wonder what the spec will be + when = is it worth waiting rather than another 1600MM-Cool? Presumably a mono version of the colour version https://astronomy-imaging-camera.com/product/asi2600mc-pro-color ? 🤨

Thanks Ken, looks convincing. For some reason I figured 3nm was better then 5nm but maybe not? Graham

I was also thinking of getting a second ZWO1600MM but am intrigued by what you're now saying about the 16bit-CMOS sensors - could you please direct me to any / alternatives to the ZWO - althougb that sounds like we're thinking of the same thing re. APS-C size? No I haven't heard of the iOptron - will take a look; one day I hope to have a static observatory + view of Polaris but for now have to work with what I have = dream on! Graha

Thanks Syed that's helpful. I'm a little concerned as I said 300s is my highest exposure due to (a) numerous aircraft and (b) I have no view of Polaris, so my PA is OK'ish (using PHD2 technique) but not sure about going to say +600s - one of the reasons I like the ZWO which being sensitive + low readout noise produces a good bang for your buck @ 300s. Graham

I've had a ZWO ASI1600MM-Cool 2nd Gen since the end of 2016 + using the ZWO 7nm 31mm filter bundle (LRGB & HaOIIISII), which I use with a WO GT81 and Bortle 5/6 skies + frequent planes as I live near Gatwick (or at least there used to be) using mainly <= 5 min subs. Although generally happy with the results I am now considering upgrading the filters either to Astrodon or Chroma. Is this a good idea / worthwhile? For NB is 3nm the way to go + what, if any, are the implications for imaging e.g. exposures, integration times etc? Graham

Thanks Dave, yes I messed up the framing after a Meridian flip! I'll give your ideas a try and next time be more careful. Graham

Can somebody please point me to a simple (short) description / video tuttorial of how to manually align and then merge two already processed images in Photoshop? I have an HOO image and corresponding RGB star image which need to be manually brought together - unfortunately the FOV of the two data sets don't naturally match but are otherwise they are the same i.e same OTA and camera. I realise there's software such as Registar and APP which I believe can do this but for the moment I'd rather not go down that track (cost). Thanks

My set of books arrived about 10-days ago and as a learner, I can say the book's very helpful - as ever, used with other online tutorials such as the excellent Light Vortex (would love to see this in book form, though very good it's tricky to use online) and Harry's Astro Shed. In addition, it is easy to use and unlike Keller's book very well produced - printing and proper binding - unlike Keller's book which for me started falling apart the day I opened it up. PixInsight still remains a tricky piece of software to learn but I'm sure these volumes will quickly become an essential part of the process and a very useful reference for all using PI. Graham

Thanks Alan, I tend to flatten image layers as I go along once happy with the result, so not sure that's an issue. However, this has got me thinking and might at least experiment with other formats (FITS / PS). I only went with Tiff as, I think, that was the default output from DSS when I started a few years ago and until now never questioned it. Graham

I only caught up with Steve Richard's Stargazine Talk "Dark Art or Magic Bullet" and was interested that he strongly recommended continuing to work with FITS files after DSS and perhaps later with the PS native files - is there any reason evidence that this produces a better outcome or is it just personal preference? For no particular reason I've always taken Tiff files from the DSS stacking pre-processing into PS and continued to work with TIFF throughout the PS post-processing until completed and need to export for the web etc. Graham

A belated thanks for Steve's excellent talk which I just caught up with today and the downloads provided. As was said in the presentation, you never stop learning with astrophotography and especially processing - much appreciated. Graham

Thank but not sure about that - assuming say any plane was travelling at say +200mph and this is a 180" exposure, surely it would just leave a trail and certainly not two images? As mentioned, I get more than my fair share of planes flying through my images and I don't think I ever recall seeing the plane itself, only a trail of their fuselage and wingtip lights. Graham

Living not far from Gatwick and Heathrow airports planes are something of an accepted hazard for my astrophotography, even in the quieter times of Covid-19. However, last night just before 10pm I got the strange result shown below on a 180 sec Luminance exposure. It has all the hallmarks of a plane with 4 x light traces but seems to have also imaged twice what looks like the tailfin - is this possible, never seen such a result before? Due to its speed I won't usually see the wings or tailfins but twice. Very curious. Graham

Ah thanks again, just checking - it's often these minor things that seem to trip me up and for some reason have not fathomed this obvioulsy simple action before, much appreciated. Graham

OK thanks that seems straight forward, except to clarify - when you say 'chart centre' I presume you mean right click on the point (O) that's generated from the Position icon data? Graham

I've looked at this before but for whatever reason can't figure out what to do: How do I input RA and DEC info in CdC for a chosen point of the sky and then slew to it using CdC? I can see Object lists and User Defined Objects but, if either of these is correct - how can this be translated to naviagtion to the said point or is there another way - preferably step-by step idiots guide please? Graham