groberts

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 

9 hours ago, Merlin66 said:

Yes. This is also the centre of the visible chart.

 

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 

I'm slowly learning PixInsight using the excellent Light Vortex online tutorial, Warren Keller's (difficult to use) book and of course, the video tutorials from Harrysastroshed.  Also puchased on pre-order a few months ago Reogelio Benrnal Andreo's new two-part box set of books - Mastering PixInsight & Reference Guide, which I've already been using online - but the real thing is always better and personally I find a book in my hands better than online for learning. 

It's therefore with great pleasure the postman today delivered from Taiwan (that's the books not the postman!) the said books, which are very well produced and packaged.  They look very promising and I especially like the reference edtion, which I've already found useful when working with the previously named learning sources in order to clarify points.  Still a long way to go but now armed with the help of all these facilties how can I fail? Famous last words!

Graham

I'm in a similar situation and will be interested to see the reponse to this question + if I may add: 

Is such an upgrade worthwhile, these filters (Chroma & Astrodon) are not cheap so  does the upgrade make noticeable imrovements and in which particular wavelengths?  

I do clean the disc using DiscCleaner and routinely scan with AVG. 

It's an old school magnetic disc - I'm very familar with the tools mentioned and is set up to run auto-fragmentation once a week.

Thanks

50 minutes ago, Dr_Ju_ju said:

One of the problems these days is that the Software developers are making use of the upgraded tools etc. but one of the knock-ons is that trying to run the software on older hardware\os's etc. without updating the 'hidden' apps e.g. .Net will produce unforeseen problems....

4Gb is more than enough to run everything, where are you saving your images to ?, is there enough free contiguous space?, how have you configured your page-file?, its usually better to have it on a separate local drive, so that it doesn't get split .... 

Not sure I undestand some of these points but I save each image direct to the hard disk, then transfer elsewhere for processing + deleting as I go along i.e. always plenty of disc space.  

On occasion my main laptop which I use for imaging crashes or like last night just hangs (mid-imaging!) and in this event can only be restartred by turning it off and rebooting.  I did this last night and thereafter all was fine for the rest of the 4-hour session.  This ony happens every now and again but, of course, it is catostrophic and a real pain mid-imaging.  It seems to me there could be one of three issues (a) software conflicts (b) something badly wrong with the computer or (c) insuffcient memory.  I'm now inclined towards the latter (c).

The computer is about six or seven years old but for any normal (non astro) use is fine and most of the time is also OK for astro too; actually I only mainly use it as my main astro computer nowadays.  It is a Samsung laptop with Intel Core i5-2467M CPU 1.60GHz chip, 4GB RAM, 64bit & Windows 7 + I'm running EQASCOM + PHD2 + CdC + APT for control & image capture - as it's mainly for astro I've removed all non esstenial programmes and mosty run it offline to eliminate unwanted conflicts etc. 

I'm now begining to think that maybe the RAM is perhaps too small and might benefit from upgrading?  Any thoughts or guidance much appreciated.

Graham 

What's the best / easiest way to combine two different image sets?

I'm currently imaging LBN 325 in narrowband @ 300sec exposures and intend to shoot another set of RGB subs @ 60sec for star colour, which I then want to combine.

I'm mostly using Photoshop + learning (slowly) PixInsight and really want to keep it as simple as possible + without purchasing / learning another software package; I appreciate there is such software that will do this?  I should have done this ages ago but too lazy! 

Thanks, Graham

Congratulations, looks great - just done the same myself, this lens is a right little belter 

Looking forwards to more use. 

re-installed and now OK 👍 

Will do, thanks.

Version 3.0.  I've been using this for over a year OK + no other problems with computer. 

I've been using FITS Viewer for a while just to check my subs before stacking - usually four or five at a time.

I'm now finding that if I load more than 2 images at a time into FITS viewer it crashes but still works fine if it's just one of two.

Anybody any idea what's causing this and how it can be fixed please?